Adding upstream version 2:9.1.0016.upstream/2%9.1.0016

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 7814 insertions, 0 deletions

diff --git a/src/window.c b/src/window.c
new file mode 100644
index 0000000..54e17be
--- /dev/null
+++ b/src/window.c
@@ -0,0 +1,7814 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read a list of people who contributed.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+#include "vim.h"
+
+static void cmd_with_count(char *cmd, char_u *bufp, size_t bufsize, long Prenum);
+static void win_init(win_T *newp, win_T *oldp, int flags);
+static void win_init_some(win_T *newp, win_T *oldp);
+static void frame_comp_pos(frame_T *topfrp, int *row, int *col);
+static void frame_setheight(frame_T *curfrp, int height);
+static void frame_setwidth(frame_T *curfrp, int width);
+static void win_exchange(long);
+static void win_rotate(int, int);
+static void win_totop(int size, int flags);
+static void win_equal_rec(win_T *next_curwin, int current, frame_T *topfr, int dir, int col, int row, int width, int height);
+static void trigger_winclosed(win_T *win);
+static win_T *win_free_mem(win_T *win, int *dirp, tabpage_T *tp);
+static frame_T *win_altframe(win_T *win, tabpage_T *tp);
+static tabpage_T *alt_tabpage(void);
+static win_T *frame2win(frame_T *frp);
+static int frame_has_win(frame_T *frp, win_T *wp);
+static void win_fix_scroll(int resize);
+static void win_fix_cursor(int normal);
+static void frame_new_height(frame_T *topfrp, int height, int topfirst, int wfh);
+static int frame_fixed_height(frame_T *frp);
+static int frame_fixed_width(frame_T *frp);
+static void frame_add_statusline(frame_T *frp);
+static void frame_new_width(frame_T *topfrp, int width, int leftfirst, int wfw);
+static void frame_add_vsep(frame_T *frp);
+static int frame_minwidth(frame_T *topfrp, win_T *next_curwin);
+static void frame_fix_width(win_T *wp);
+static int win_alloc_firstwin(win_T *oldwin);
+static void new_frame(win_T *wp);
+static tabpage_T *alloc_tabpage(void);
+static int leave_tabpage(buf_T *new_curbuf, int trigger_leave_autocmds);
+static void enter_tabpage(tabpage_T *tp, buf_T *old_curbuf, int trigger_enter_autocmds, int trigger_leave_autocmds);
+static void frame_fix_height(win_T *wp);
+static int frame_minheight(frame_T *topfrp, win_T *next_curwin);
+static int may_open_tabpage(void);
+static int win_enter_ext(win_T *wp, int flags);
+static void win_free(win_T *wp, tabpage_T *tp);
+static void win_append(win_T *after, win_T *wp);
+static void frame_append(frame_T *after, frame_T *frp);
+static void frame_insert(frame_T *before, frame_T *frp);
+static void frame_remove(frame_T *frp);
+static void win_goto_ver(int up, long count);
+static void win_goto_hor(int left, long count);
+static void frame_add_height(frame_T *frp, int n);
+static void last_status_rec(frame_T *fr, int statusline);
+
+static void make_snapshot_rec(frame_T *fr, frame_T **frp);
+static void clear_snapshot(tabpage_T *tp, int idx);
+static void clear_snapshot_rec(frame_T *fr);
+static int check_snapshot_rec(frame_T *sn, frame_T *fr);
+static win_T *restore_snapshot_rec(frame_T *sn, frame_T *fr);
+static win_T *get_snapshot_curwin(int idx);
+
+static int frame_check_height(frame_T *topfrp, int height);
+static int frame_check_width(frame_T *topfrp, int width);
+
+static win_T *win_alloc(win_T *after, int hidden);
+
+#define NOWIN		((win_T *)-1)	// non-existing window
+
+#define ROWS_AVAIL (Rows - p_ch - tabline_height())
+
+// flags for win_enter_ext()
+#define WEE_UNDO_SYNC			0x01
+#define WEE_CURWIN_INVALID		0x02
+#define WEE_TRIGGER_NEW_AUTOCMDS	0x04
+#define WEE_TRIGGER_ENTER_AUTOCMDS	0x08
+#define WEE_TRIGGER_LEAVE_AUTOCMDS	0x10
+#define WEE_ALLOW_PARSE_MESSAGES	0x20
+
+static char *m_onlyone = N_("Already only one window");
+
+// When non-zero splitting a window is forbidden.  Used to avoid that nasty
+// autocommands mess up the window structure.
+static int split_disallowed = 0;
+
+// When non-zero closing a window is forbidden.  Used to avoid that nasty
+// autocommands mess up the window structure.
+static int close_disallowed = 0;
+
+/*
+ * Disallow changing the window layout (split window, close window, move
+ * window).  Resizing is still allowed.
+ * Used for autocommands that temporarily use another window and need to
+ * make sure the previously selected window is still there.
+ * Must be matched with exactly one call to window_layout_unlock()!
+ */
+    static void
+window_layout_lock(void)
+{
+    ++split_disallowed;
+    ++close_disallowed;
+}
+
+    static void
+window_layout_unlock(void)
+{
+    --split_disallowed;
+    --close_disallowed;
+}
+
+/*
+ * When the window layout cannot be changed give an error and return TRUE.
+ * "cmd" indicates the action being performed and is used to pick the relevant
+ * error message.
+ */
+    int
+window_layout_locked(enum CMD_index cmd)
+{
+    if (split_disallowed > 0 || close_disallowed > 0)
+    {
+	if (close_disallowed == 0 && cmd == CMD_tabnew)
+	    emsg(_(e_cannot_split_window_when_closing_buffer));
+	else
+	    emsg(_(e_not_allowed_to_change_window_layout_in_this_autocmd));
+	return TRUE;
+    }
+    return FALSE;
+}
+
+// #define WIN_DEBUG
+#ifdef WIN_DEBUG
+/*
+ * Call this method to log the current window layout.
+ */
+    static void
+log_frame_layout(frame_T *frame)
+{
+    ch_log(NULL, "layout %s, wi: %d, he: %d, wwi: %d, whe: %d, id: %d",
+	    frame->fr_layout == FR_LEAF ? "LEAF"
+				  : frame->fr_layout == FR_ROW ? "ROW" : "COL",
+	    frame->fr_width,
+	    frame->fr_height,
+	    frame->fr_win == NULL ? -1 : frame->fr_win->w_width,
+	    frame->fr_win == NULL ? -1 : frame->fr_win->w_height,
+	    frame->fr_win == NULL ? -1 : frame->fr_win->w_id);
+    if (frame->fr_child != NULL)
+    {
+	ch_log(NULL, "children");
+	log_frame_layout(frame->fr_child);
+	if (frame->fr_next != NULL)
+	    ch_log(NULL, "END of children");
+    }
+    if (frame->fr_next != NULL)
+	log_frame_layout(frame->fr_next);
+}
+#endif
+
+/*
+ * Return the current window, unless in the cmdline window and "prevwin" is
+ * set, then return "prevwin".
+ */
+    win_T *
+prevwin_curwin(void)
+{
+    // In cmdwin, the alternative buffer should be used.
+    return is_in_cmdwin() && prevwin != NULL ? prevwin : curwin;
+}
+
+/*
+ * If the 'switchbuf' option contains "useopen" or "usetab", then try to jump
+ * to a window containing "buf".
+ * Returns the pointer to the window that was jumped to or NULL.
+ */
+    win_T *
+swbuf_goto_win_with_buf(buf_T *buf)
+{
+    win_T   *wp = NULL;
+
+    if (buf == NULL)
+	return wp;
+
+    // If 'switchbuf' contains "useopen": jump to first window in the current
+    // tab page containing "buf" if one exists.
+    if (swb_flags & SWB_USEOPEN)
+	wp = buf_jump_open_win(buf);
+
+    // If 'switchbuf' contains "usetab": jump to first window in any tab page
+    // containing "buf" if one exists.
+    if (wp == NULL && (swb_flags & SWB_USETAB))
+	wp = buf_jump_open_tab(buf);
+
+    return wp;
+}
+
+/*
+ * All CTRL-W window commands are handled here, called from normal_cmd().
+ */
+    void
+do_window(
+    int		nchar,
+    long	Prenum,
+    int		xchar)	    // extra char from ":wincmd gx" or NUL
+{
+    long	Prenum1;
+    win_T	*wp;
+    char_u	*ptr;
+    linenr_T    lnum = -1;
+#ifdef FEAT_FIND_ID
+    int		type = FIND_DEFINE;
+    int		len;
+#endif
+    char_u	cbuf[40];
+
+    if (ERROR_IF_ANY_POPUP_WINDOW)
+	return;
+
+#define CHECK_CMDWIN \
+    do { \
+	if (cmdwin_type != 0) \
+	{ \
+	    emsg(_(e_invalid_in_cmdline_window)); \
+	    return; \
+	} \
+    } while (0)
+
+    Prenum1 = Prenum == 0 ? 1 : Prenum;
+
+    switch (nchar)
+    {
+// split current window in two parts, horizontally
+    case 'S':
+    case Ctrl_S:
+    case 's':
+		CHECK_CMDWIN;
+		reset_VIsual_and_resel();	// stop Visual mode
+		// When splitting the quickfix window open a new buffer in it,
+		// don't replicate the quickfix buffer.
+		if (bt_quickfix(curbuf))
+		    goto newwindow;
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		(void)win_split((int)Prenum, 0);
+		break;
+
+// split current window in two parts, vertically
+    case Ctrl_V:
+    case 'v':
+		CHECK_CMDWIN;
+		reset_VIsual_and_resel();	// stop Visual mode
+		// When splitting the quickfix window open a new buffer in it,
+		// don't replicate the quickfix buffer.
+		if (bt_quickfix(curbuf))
+		    goto newwindow;
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		(void)win_split((int)Prenum, WSP_VERT);
+		break;
+
+// split current window and edit alternate file
+    case Ctrl_HAT:
+    case '^':
+		CHECK_CMDWIN;
+		reset_VIsual_and_resel();	// stop Visual mode
+
+		if (buflist_findnr(Prenum == 0
+					? curwin->w_alt_fnum : Prenum) == NULL)
+		{
+		    if (Prenum == 0)
+			emsg(_(e_no_alternate_file));
+		    else
+			semsg(_(e_buffer_nr_not_found), Prenum);
+		    break;
+		}
+
+		if (!curbuf_locked() && win_split(0, 0) == OK)
+		    (void)buflist_getfile(
+			    Prenum == 0 ? curwin->w_alt_fnum : Prenum,
+			    (linenr_T)0, GETF_ALT, FALSE);
+		break;
+
+// open new window
+    case Ctrl_N:
+    case 'n':
+		CHECK_CMDWIN;
+		reset_VIsual_and_resel();	// stop Visual mode
+newwindow:
+		if (Prenum)
+		    // window height
+		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
+		else
+		    cbuf[0] = NUL;
+#if defined(FEAT_QUICKFIX)
+		if (nchar == 'v' || nchar == Ctrl_V)
+		    STRCAT(cbuf, "v");
+#endif
+		STRCAT(cbuf, "new");
+		do_cmdline_cmd(cbuf);
+		break;
+
+// quit current window
+    case Ctrl_Q:
+    case 'q':
+		reset_VIsual_and_resel();	// stop Visual mode
+		cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
+		do_cmdline_cmd(cbuf);
+		break;
+
+// close current window
+    case Ctrl_C:
+    case 'c':
+		reset_VIsual_and_resel();	// stop Visual mode
+		cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
+		do_cmdline_cmd(cbuf);
+		break;
+
+#if defined(FEAT_QUICKFIX)
+// close preview window
+    case Ctrl_Z:
+    case 'z':
+		CHECK_CMDWIN;
+		reset_VIsual_and_resel();	// stop Visual mode
+		do_cmdline_cmd((char_u *)"pclose");
+		break;
+
+// cursor to preview window
+    case 'P':
+		FOR_ALL_WINDOWS(wp)
+		    if (wp->w_p_pvw)
+			break;
+		if (wp == NULL)
+		    emsg(_(e_there_is_no_preview_window));
+		else
+		    win_goto(wp);
+		break;
+#endif
+
+// close all but current window
+    case Ctrl_O:
+    case 'o':
+		CHECK_CMDWIN;
+		reset_VIsual_and_resel();	// stop Visual mode
+		cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
+		do_cmdline_cmd(cbuf);
+		break;
+
+// cursor to next window with wrap around
+    case Ctrl_W:
+    case 'w':
+// cursor to previous window with wrap around
+    case 'W':
+		CHECK_CMDWIN;
+		if (ONE_WINDOW && Prenum != 1)	// just one window
+		    beep_flush();
+		else
+		{
+		    if (Prenum)			// go to specified window
+		    {
+			for (wp = firstwin; --Prenum > 0; )
+			{
+			    if (wp->w_next == NULL)
+				break;
+			    else
+				wp = wp->w_next;
+			}
+		    }
+		    else
+		    {
+			if (nchar == 'W')	    // go to previous window
+			{
+			    wp = curwin->w_prev;
+			    if (wp == NULL)
+				wp = lastwin;	    // wrap around
+			}
+			else			    // go to next window
+			{
+			    wp = curwin->w_next;
+			    if (wp == NULL)
+				wp = firstwin;	    // wrap around
+			}
+		    }
+		    win_goto(wp);
+		}
+		break;
+
+// cursor to window below
+    case 'j':
+    case K_DOWN:
+    case Ctrl_J:
+		CHECK_CMDWIN;
+		win_goto_ver(FALSE, Prenum1);
+		break;
+
+// cursor to window above
+    case 'k':
+    case K_UP:
+    case Ctrl_K:
+		CHECK_CMDWIN;
+		win_goto_ver(TRUE, Prenum1);
+		break;
+
+// cursor to left window
+    case 'h':
+    case K_LEFT:
+    case Ctrl_H:
+    case K_BS:
+		CHECK_CMDWIN;
+		win_goto_hor(TRUE, Prenum1);
+		break;
+
+// cursor to right window
+    case 'l':
+    case K_RIGHT:
+    case Ctrl_L:
+		CHECK_CMDWIN;
+		win_goto_hor(FALSE, Prenum1);
+		break;
+
+// move window to new tab page
+    case 'T':
+		CHECK_CMDWIN;
+		if (one_window())
+		    msg(_(m_onlyone));
+		else
+		{
+		    tabpage_T	*oldtab = curtab;
+		    tabpage_T	*newtab;
+
+		    // First create a new tab with the window, then go back to
+		    // the old tab and close the window there.
+		    wp = curwin;
+		    if (win_new_tabpage((int)Prenum) == OK
+						     && valid_tabpage(oldtab))
+		    {
+			newtab = curtab;
+			goto_tabpage_tp(oldtab, TRUE, TRUE);
+			if (curwin == wp)
+			    win_close(curwin, FALSE);
+			if (valid_tabpage(newtab))
+			    goto_tabpage_tp(newtab, TRUE, TRUE);
+		    }
+		}
+		break;
+
+// cursor to top-left window
+    case 't':
+    case Ctrl_T:
+		win_goto(firstwin);
+		break;
+
+// cursor to bottom-right window
+    case 'b':
+    case Ctrl_B:
+		win_goto(lastwin);
+		break;
+
+// cursor to last accessed (previous) window
+    case 'p':
+    case Ctrl_P:
+		if (!win_valid(prevwin))
+		    beep_flush();
+		else
+		    win_goto(prevwin);
+		break;
+
+// exchange current and next window
+    case 'x':
+    case Ctrl_X:
+		CHECK_CMDWIN;
+		win_exchange(Prenum);
+		break;
+
+// rotate windows downwards
+    case Ctrl_R:
+    case 'r':
+		CHECK_CMDWIN;
+		reset_VIsual_and_resel();	// stop Visual mode
+		win_rotate(FALSE, (int)Prenum1);    // downwards
+		break;
+
+// rotate windows upwards
+    case 'R':
+		CHECK_CMDWIN;
+		reset_VIsual_and_resel();	// stop Visual mode
+		win_rotate(TRUE, (int)Prenum1);	    // upwards
+		break;
+
+// move window to the very top/bottom/left/right
+    case 'K':
+    case 'J':
+    case 'H':
+    case 'L':
+		CHECK_CMDWIN;
+		win_totop((int)Prenum,
+			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
+			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
+		break;
+
+// make all windows the same width and/or height
+    case '=':
+		{
+		    int mod = cmdmod.cmod_split & (WSP_VERT | WSP_HOR);
+#ifdef FEAT_GUI
+		    need_mouse_correct = TRUE;
+#endif
+		    win_equal(NULL, FALSE,
+			   mod == WSP_VERT ? 'v' : mod == WSP_HOR ? 'h' : 'b');
+		}
+		break;
+
+// increase current window height
+    case '+':
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		win_setheight(curwin->w_height + (int)Prenum1);
+		break;
+
+// decrease current window height
+    case '-':
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		win_setheight(curwin->w_height - (int)Prenum1);
+		break;
+
+// set current window height
+    case Ctrl__:
+    case '_':
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		win_setheight(Prenum ? (int)Prenum : 9999);
+		break;
+
+// increase current window width
+    case '>':
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		win_setwidth(curwin->w_width + (int)Prenum1);
+		break;
+
+// decrease current window width
+    case '<':
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		win_setwidth(curwin->w_width - (int)Prenum1);
+		break;
+
+// set current window width
+    case '|':
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
+		break;
+
+// jump to tag and split window if tag exists (in preview window)
+#if defined(FEAT_QUICKFIX)
+    case '}':
+		CHECK_CMDWIN;
+		if (Prenum)
+		    g_do_tagpreview = Prenum;
+		else
+		    g_do_tagpreview = p_pvh;
+#endif
+		// FALLTHROUGH
+    case ']':
+    case Ctrl_RSB:
+		CHECK_CMDWIN;
+		// keep Visual mode, can select words to use as a tag
+		if (Prenum)
+		    postponed_split = Prenum;
+		else
+		    postponed_split = -1;
+#ifdef FEAT_QUICKFIX
+		if (nchar != '}')
+		    g_do_tagpreview = 0;
+#endif
+
+		// Execute the command right here, required when "wincmd ]"
+		// was used in a function.
+		do_nv_ident(Ctrl_RSB, NUL);
+		postponed_split = 0;
+		break;
+
+// edit file name under cursor in a new window
+    case 'f':
+    case 'F':
+    case Ctrl_F:
+wingotofile:
+		CHECK_CMDWIN;
+		if (check_text_or_curbuf_locked(NULL))
+		    break;
+
+		ptr = grab_file_name(Prenum1, &lnum);
+		if (ptr != NULL)
+		{
+		    tabpage_T	*oldtab = curtab;
+		    win_T	*oldwin = curwin;
+#ifdef FEAT_GUI
+		    need_mouse_correct = TRUE;
+#endif
+		    setpcmark();
+
+		    // If 'switchbuf' is set to 'useopen' or 'usetab' and the
+		    // file is already opened in a window, then jump to it.
+		    wp = NULL;
+		    if ((swb_flags & (SWB_USEOPEN | SWB_USETAB))
+						&& cmdmod.cmod_tab == 0)
+			wp = swbuf_goto_win_with_buf(buflist_findname_exp(ptr));
+
+		    if (wp == NULL && win_split(0, 0) == OK)
+		    {
+			RESET_BINDING(curwin);
+			if (do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
+						   ECMD_HIDE, NULL) == FAIL)
+			{
+			    // Failed to open the file, close the window
+			    // opened for it.
+			    win_close(curwin, FALSE);
+			    goto_tabpage_win(oldtab, oldwin);
+			}
+			else
+			    wp = curwin;
+		    }
+
+		    if (wp != NULL && nchar == 'F' && lnum >= 0)
+		    {
+			curwin->w_cursor.lnum = lnum;
+			check_cursor_lnum();
+			beginline(BL_SOL | BL_FIX);
+		    }
+		    vim_free(ptr);
+		}
+		break;
+
+#ifdef FEAT_FIND_ID
+// Go to the first occurrence of the identifier under cursor along path in a
+// new window -- webb
+    case 'i':			    // Go to any match
+    case Ctrl_I:
+		type = FIND_ANY;
+		// FALLTHROUGH
+    case 'd':			    // Go to definition, using 'define'
+    case Ctrl_D:
+		CHECK_CMDWIN;
+		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
+		    break;
+
+		// Make a copy, if the line was changed it will be freed.
+		ptr = vim_strnsave(ptr, len);
+		if (ptr == NULL)
+		    break;
+
+		find_pattern_in_path(ptr, 0, len, TRUE,
+			Prenum == 0 ? TRUE : FALSE, type,
+			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
+		vim_free(ptr);
+		curwin->w_set_curswant = TRUE;
+		break;
+#endif
+
+// Quickfix window only: view the result under the cursor in a new split.
+#if defined(FEAT_QUICKFIX)
+    case K_KENTER:
+    case CAR:
+		if (bt_quickfix(curbuf))
+		    qf_view_result(TRUE);
+		break;
+#endif
+
+// CTRL-W g  extended commands
+    case 'g':
+    case Ctrl_G:
+		CHECK_CMDWIN;
+#ifdef USE_ON_FLY_SCROLL
+		dont_scroll = TRUE;		// disallow scrolling here
+#endif
+		++no_mapping;
+		++allow_keys;   // no mapping for xchar, but allow key codes
+		if (xchar == NUL)
+		    xchar = plain_vgetc();
+		LANGMAP_ADJUST(xchar, TRUE);
+		--no_mapping;
+		--allow_keys;
+		(void)add_to_showcmd(xchar);
+
+		switch (xchar)
+		{
+#if defined(FEAT_QUICKFIX)
+		    case '}':
+			xchar = Ctrl_RSB;
+			if (Prenum)
+			    g_do_tagpreview = Prenum;
+			else
+			    g_do_tagpreview = p_pvh;
+#endif
+			// FALLTHROUGH
+		    case ']':
+		    case Ctrl_RSB:
+			// keep Visual mode, can select words to use as a tag
+			if (Prenum)
+			    postponed_split = Prenum;
+			else
+			    postponed_split = -1;
+
+			// Execute the command right here, required when
+			// "wincmd g}" was used in a function.
+			do_nv_ident('g', xchar);
+			postponed_split = 0;
+			break;
+
+		    case 'f':	    // CTRL-W gf: "gf" in a new tab page
+		    case 'F':	    // CTRL-W gF: "gF" in a new tab page
+			cmdmod.cmod_tab = tabpage_index(curtab) + 1;
+			nchar = xchar;
+			goto wingotofile;
+
+		    case 't':	    // CTRL-W gt: go to next tab page
+			goto_tabpage((int)Prenum);
+			break;
+
+		    case 'T':	    // CTRL-W gT: go to previous tab page
+			goto_tabpage(-(int)Prenum1);
+			break;
+
+		    case TAB:	    // CTRL-W g<Tab>: go to last used tab page
+			if (goto_tabpage_lastused() == FAIL)
+			    beep_flush();
+			break;
+
+		    default:
+			beep_flush();
+			break;
+		}
+		break;
+
+    default:	beep_flush();
+		break;
+    }
+}
+
+/*
+ * Figure out the address type for ":wincmd".
+ */
+    void
+get_wincmd_addr_type(char_u *arg, exarg_T *eap)
+{
+    switch (*arg)
+    {
+    case 'S':
+    case Ctrl_S:
+    case 's':
+    case Ctrl_N:
+    case 'n':
+    case 'j':
+    case Ctrl_J:
+    case 'k':
+    case Ctrl_K:
+    case 'T':
+    case Ctrl_R:
+    case 'r':
+    case 'R':
+    case 'K':
+    case 'J':
+    case '+':
+    case '-':
+    case Ctrl__:
+    case '_':
+    case '|':
+    case ']':
+    case Ctrl_RSB:
+    case 'g':
+    case Ctrl_G:
+    case Ctrl_V:
+    case 'v':
+    case 'h':
+    case Ctrl_H:
+    case 'l':
+    case Ctrl_L:
+    case 'H':
+    case 'L':
+    case '>':
+    case '<':
+#if defined(FEAT_QUICKFIX)
+    case '}':
+#endif
+    case 'f':
+    case 'F':
+    case Ctrl_F:
+#ifdef FEAT_FIND_ID
+    case 'i':
+    case Ctrl_I:
+    case 'd':
+    case Ctrl_D:
+#endif
+		// window size or any count
+		eap->addr_type = ADDR_OTHER;
+		break;
+
+    case Ctrl_HAT:
+    case '^':
+		// buffer number
+		eap->addr_type = ADDR_BUFFERS;
+		break;
+
+    case Ctrl_Q:
+    case 'q':
+    case Ctrl_C:
+    case 'c':
+    case Ctrl_O:
+    case 'o':
+    case Ctrl_W:
+    case 'w':
+    case 'W':
+    case 'x':
+    case Ctrl_X:
+		// window number
+		eap->addr_type = ADDR_WINDOWS;
+		break;
+
+#if defined(FEAT_QUICKFIX)
+    case Ctrl_Z:
+    case 'z':
+    case 'P':
+#endif
+    case 't':
+    case Ctrl_T:
+    case 'b':
+    case Ctrl_B:
+    case 'p':
+    case Ctrl_P:
+    case '=':
+    case CAR:
+		// no count
+		eap->addr_type = ADDR_NONE;
+		break;
+    }
+}
+
+    static void
+cmd_with_count(
+    char	*cmd,
+    char_u	*bufp,
+    size_t	bufsize,
+    long	Prenum)
+{
+    if (Prenum > 0)
+	vim_snprintf((char *)bufp, bufsize, "%s %ld", cmd, Prenum);
+    else
+	STRCPY(bufp, cmd);
+}
+
+/*
+ * If "split_disallowed" is set give an error and return FAIL.
+ * Otherwise return OK.
+ */
+    static int
+check_split_disallowed(void)
+{
+    if (split_disallowed > 0)
+    {
+	emsg(_(e_cant_split_window_while_closing_another));
+	return FAIL;
+    }
+    if (curwin->w_buffer->b_locked_split)
+    {
+	emsg(_(e_cannot_split_window_when_closing_buffer));
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * split the current window, implements CTRL-W s and :split
+ *
+ * "size" is the height or width for the new window, 0 to use half of current
+ * height or width.
+ *
+ * "flags":
+ * WSP_ROOM: require enough room for new window
+ * WSP_VERT: vertical split.
+ * WSP_TOP:  open window at the top-left of the shell (help window).
+ * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
+ * WSP_HELP: creating the help window, keep layout snapshot
+ *
+ * return FAIL for failure, OK otherwise
+ */
+    int
+win_split(int size, int flags)
+{
+    if (ERROR_IF_ANY_POPUP_WINDOW)
+	return FAIL;
+
+    if (check_split_disallowed() == FAIL)
+	return FAIL;
+
+    // When the ":tab" modifier was used open a new tab page instead.
+    if (may_open_tabpage() == OK)
+	return OK;
+
+    // Add flags from ":vertical", ":topleft" and ":botright".
+    flags |= cmdmod.cmod_split;
+    if ((flags & WSP_TOP) && (flags & WSP_BOT))
+    {
+	emsg(_(e_cant_split_topleft_and_botright_at_the_same_time));
+	return FAIL;
+    }
+
+    // When creating the help window make a snapshot of the window layout.
+    // Otherwise clear the snapshot, it's now invalid.
+    if (flags & WSP_HELP)
+	make_snapshot(SNAP_HELP_IDX);
+    else
+	clear_snapshot(curtab, SNAP_HELP_IDX);
+
+    return win_split_ins(size, flags, NULL, 0);
+}
+
+/*
+ * When "new_wp" is NULL: split the current window in two.
+ * When "new_wp" is not NULL: insert this window at the far
+ * top/left/right/bottom.
+ * Return FAIL for failure, OK otherwise.
+ */
+    int
+win_split_ins(
+    int		size,
+    int		flags,
+    win_T	*new_wp,
+    int		dir)
+{
+    win_T	*wp = new_wp;
+    win_T	*oldwin;
+    int		new_size = size;
+    int		i;
+    int		need_status = 0;
+    int		do_equal = FALSE;
+    int		needed;
+    int		available;
+    int		oldwin_height = 0;
+    int		layout;
+    frame_T	*frp, *curfrp, *frp2, *prevfrp;
+    int		before;
+    int		minheight;
+    int		wmh1;
+    int		did_set_fraction = FALSE;
+    int		retval = FAIL;
+
+    // Do not redraw here, curwin->w_buffer may be invalid.
+    ++RedrawingDisabled;
+
+    if (flags & WSP_TOP)
+	oldwin = firstwin;
+    else if (flags & WSP_BOT)
+	oldwin = lastwin;
+    else
+	oldwin = curwin;
+
+    // add a status line when p_ls == 1 and splitting the first window
+    if (ONE_WINDOW && p_ls == 1 && oldwin->w_status_height == 0)
+    {
+	if (VISIBLE_HEIGHT(oldwin) <= p_wmh && new_wp == NULL)
+	{
+	    emsg(_(e_not_enough_room));
+	    goto theend;
+	}
+	need_status = STATUS_HEIGHT;
+    }
+
+#ifdef FEAT_GUI
+    // May be needed for the scrollbars that are going to change.
+    if (gui.in_use)
+	out_flush();
+#endif
+
+    if (flags & WSP_VERT)
+    {
+	int	wmw1;
+	int	minwidth;
+
+	layout = FR_ROW;
+
+	/*
+	 * Check if we are able to split the current window and compute its
+	 * width.
+	 */
+	// Current window requires at least 1 space.
+	wmw1 = (p_wmw == 0 ? 1 : p_wmw);
+	needed = wmw1 + 1;
+	if (flags & WSP_ROOM)
+	    needed += p_wiw - wmw1;
+	if (flags & (WSP_BOT | WSP_TOP))
+	{
+	    minwidth = frame_minwidth(topframe, NOWIN);
+	    available = topframe->fr_width;
+	    needed += minwidth;
+	}
+	else if (p_ea)
+	{
+	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
+	    prevfrp = oldwin->w_frame;
+	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
+							frp = frp->fr_parent)
+	    {
+		if (frp->fr_layout == FR_ROW)
+		    FOR_ALL_FRAMES(frp2, frp->fr_child)
+			if (frp2 != prevfrp)
+			    minwidth += frame_minwidth(frp2, NOWIN);
+		prevfrp = frp;
+	    }
+	    available = topframe->fr_width;
+	    needed += minwidth;
+	}
+	else
+	{
+	    minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
+	    available = oldwin->w_frame->fr_width;
+	    needed += minwidth;
+	}
+	if (available < needed && new_wp == NULL)
+	{
+	    emsg(_(e_not_enough_room));
+	    goto theend;
+	}
+	if (new_size == 0)
+	    new_size = oldwin->w_width / 2;
+	if (new_size > available - minwidth - 1)
+	    new_size = available - minwidth - 1;
+	if (new_size < wmw1)
+	    new_size = wmw1;
+
+	// if it doesn't fit in the current window, need win_equal()
+	if (oldwin->w_width - new_size - 1 < p_wmw)
+	    do_equal = TRUE;
+
+	// We don't like to take lines for the new window from a
+	// 'winfixwidth' window.  Take them from a window to the left or right
+	// instead, if possible. Add one for the separator.
+	if (oldwin->w_p_wfw)
+	    win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
+
+	// Only make all windows the same width if one of them (except oldwin)
+	// is wider than one of the split windows.
+	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
+					 && oldwin->w_frame->fr_parent != NULL)
+	{
+	    frp = oldwin->w_frame->fr_parent->fr_child;
+	    while (frp != NULL)
+	    {
+		if (frp->fr_win != oldwin && frp->fr_win != NULL
+			&& (frp->fr_win->w_width > new_size
+			    || frp->fr_win->w_width > oldwin->w_width
+							      - new_size - 1))
+		{
+		    do_equal = TRUE;
+		    break;
+		}
+		frp = frp->fr_next;
+	    }
+	}
+    }
+    else
+    {
+	layout = FR_COL;
+
+	/*
+	 * Check if we are able to split the current window and compute its
+	 * height.
+	 */
+	// Current window requires at least 1 space.
+	wmh1 = (p_wmh == 0 ? 1 : p_wmh) + WINBAR_HEIGHT(curwin);
+	needed = wmh1 + STATUS_HEIGHT;
+	if (flags & WSP_ROOM)
+	    needed += p_wh - wmh1;
+	if (flags & (WSP_BOT | WSP_TOP))
+	{
+	    minheight = frame_minheight(topframe, NOWIN) + need_status;
+	    available = topframe->fr_height;
+	    needed += minheight;
+	}
+	else if (p_ea)
+	{
+	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
+	    prevfrp = oldwin->w_frame;
+	    for (frp = oldwin->w_frame->fr_parent; frp != NULL;
+							frp = frp->fr_parent)
+	    {
+		if (frp->fr_layout == FR_COL)
+		    FOR_ALL_FRAMES(frp2, frp->fr_child)
+			if (frp2 != prevfrp)
+			    minheight += frame_minheight(frp2, NOWIN);
+		prevfrp = frp;
+	    }
+	    available = topframe->fr_height;
+	    needed += minheight;
+	}
+	else
+	{
+	    minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
+	    available = oldwin->w_frame->fr_height;
+	    needed += minheight;
+	}
+	if (available < needed && new_wp == NULL)
+	{
+	    emsg(_(e_not_enough_room));
+	    goto theend;
+	}
+	oldwin_height = oldwin->w_height;
+	if (need_status)
+	{
+	    oldwin->w_status_height = STATUS_HEIGHT;
+	    oldwin_height -= STATUS_HEIGHT;
+	}
+	if (new_size == 0)
+	    new_size = oldwin_height / 2;
+	if (new_size > available - minheight - STATUS_HEIGHT)
+	    new_size = available - minheight - STATUS_HEIGHT;
+	if (new_size < wmh1)
+	    new_size = wmh1;
+
+	// if it doesn't fit in the current window, need win_equal()
+	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
+	    do_equal = TRUE;
+
+	// We don't like to take lines for the new window from a
+	// 'winfixheight' window.  Take them from a window above or below
+	// instead, if possible.
+	if (oldwin->w_p_wfh)
+	{
+	    // Set w_fraction now so that the cursor keeps the same relative
+	    // vertical position using the old height.
+	    set_fraction(oldwin);
+	    did_set_fraction = TRUE;
+
+	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
+								      oldwin);
+	    oldwin_height = oldwin->w_height;
+	    if (need_status)
+		oldwin_height -= STATUS_HEIGHT;
+	}
+
+	// Only make all windows the same height if one of them (except oldwin)
+	// is higher than one of the split windows.
+	if (!do_equal && p_ea && size == 0 && *p_ead != 'h'
+	   && oldwin->w_frame->fr_parent != NULL)
+	{
+	    frp = oldwin->w_frame->fr_parent->fr_child;
+	    while (frp != NULL)
+	    {
+		if (frp->fr_win != oldwin && frp->fr_win != NULL
+			&& (frp->fr_win->w_height > new_size
+			    || frp->fr_win->w_height > oldwin_height - new_size
+							      - STATUS_HEIGHT))
+		{
+		    do_equal = TRUE;
+		    break;
+		}
+		frp = frp->fr_next;
+	    }
+	}
+    }
+
+    /*
+     * allocate new window structure and link it in the window list
+     */
+    if ((flags & WSP_TOP) == 0
+	    && ((flags & WSP_BOT)
+		|| (flags & WSP_BELOW)
+		|| (!(flags & WSP_ABOVE)
+		    && ( (flags & WSP_VERT) ? p_spr : p_sb))))
+    {
+	// new window below/right of current one
+	if (new_wp == NULL)
+	    wp = win_alloc(oldwin, FALSE);
+	else
+	    win_append(oldwin, wp);
+    }
+    else
+    {
+	if (new_wp == NULL)
+	    wp = win_alloc(oldwin->w_prev, FALSE);
+	else
+	    win_append(oldwin->w_prev, wp);
+    }
+
+    if (new_wp == NULL)
+    {
+	if (wp == NULL)
+	    goto theend;
+
+	new_frame(wp);
+	if (wp->w_frame == NULL)
+	{
+	    win_free(wp, NULL);
+	    goto theend;
+	}
+
+	// make the contents of the new window the same as the current one
+	win_init(wp, curwin, flags);
+    }
+
+    /*
+     * Reorganise the tree of frames to insert the new window.
+     */
+    if (flags & (WSP_TOP | WSP_BOT))
+    {
+	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
+	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
+	{
+	    curfrp = topframe->fr_child;
+	    if (flags & WSP_BOT)
+		while (curfrp->fr_next != NULL)
+		    curfrp = curfrp->fr_next;
+	}
+	else
+	    curfrp = topframe;
+	before = (flags & WSP_TOP);
+    }
+    else
+    {
+	curfrp = oldwin->w_frame;
+	if (flags & WSP_BELOW)
+	    before = FALSE;
+	else if (flags & WSP_ABOVE)
+	    before = TRUE;
+	else if (flags & WSP_VERT)
+	    before = !p_spr;
+	else
+	    before = !p_sb;
+    }
+    if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
+    {
+	// Need to create a new frame in the tree to make a branch.
+	frp = ALLOC_CLEAR_ONE(frame_T);
+	*frp = *curfrp;
+	curfrp->fr_layout = layout;
+	frp->fr_parent = curfrp;
+	frp->fr_next = NULL;
+	frp->fr_prev = NULL;
+	curfrp->fr_child = frp;
+	curfrp->fr_win = NULL;
+	curfrp = frp;
+	if (frp->fr_win != NULL)
+	    oldwin->w_frame = frp;
+	else
+	    FOR_ALL_FRAMES(frp, frp->fr_child)
+		frp->fr_parent = curfrp;
+    }
+
+    if (new_wp == NULL)
+	frp = wp->w_frame;
+    else
+	frp = new_wp->w_frame;
+    frp->fr_parent = curfrp->fr_parent;
+
+    // Insert the new frame at the right place in the frame list.
+    if (before)
+	frame_insert(curfrp, frp);
+    else
+	frame_append(curfrp, frp);
+
+    // Set w_fraction now so that the cursor keeps the same relative
+    // vertical position.
+    if (!did_set_fraction)
+	set_fraction(oldwin);
+    wp->w_fraction = oldwin->w_fraction;
+
+    if (flags & WSP_VERT)
+    {
+	wp->w_p_scr = curwin->w_p_scr;
+
+	if (need_status)
+	{
+	    win_new_height(oldwin, oldwin->w_height - 1);
+	    oldwin->w_status_height = need_status;
+	}
+	if (flags & (WSP_TOP | WSP_BOT))
+	{
+	    // set height and row of new window to full height
+	    wp->w_winrow = tabline_height();
+	    win_new_height(wp, curfrp->fr_height - (p_ls > 0)
+							  - WINBAR_HEIGHT(wp));
+	    wp->w_status_height = (p_ls > 0);
+	}
+	else
+	{
+	    // height and row of new window is same as current window
+	    wp->w_winrow = oldwin->w_winrow;
+	    win_new_height(wp, VISIBLE_HEIGHT(oldwin));
+	    wp->w_status_height = oldwin->w_status_height;
+	}
+	frp->fr_height = curfrp->fr_height;
+
+	// "new_size" of the current window goes to the new window, use
+	// one column for the vertical separator
+	win_new_width(wp, new_size);
+	if (before)
+	    wp->w_vsep_width = 1;
+	else
+	{
+	    wp->w_vsep_width = oldwin->w_vsep_width;
+	    oldwin->w_vsep_width = 1;
+	}
+	if (flags & (WSP_TOP | WSP_BOT))
+	{
+	    if (flags & WSP_BOT)
+		frame_add_vsep(curfrp);
+	    // Set width of neighbor frame
+	    frame_new_width(curfrp, curfrp->fr_width
+		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
+								       FALSE);
+	}
+	else
+	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
+	if (before)	// new window left of current one
+	{
+	    wp->w_wincol = oldwin->w_wincol;
+	    oldwin->w_wincol += new_size + 1;
+	}
+	else		// new window right of current one
+	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
+	frame_fix_width(oldwin);
+	frame_fix_width(wp);
+    }
+    else
+    {
+	// width and column of new window is same as current window
+	if (flags & (WSP_TOP | WSP_BOT))
+	{
+	    wp->w_wincol = 0;
+	    win_new_width(wp, Columns);
+	    wp->w_vsep_width = 0;
+	}
+	else
+	{
+	    wp->w_wincol = oldwin->w_wincol;
+	    win_new_width(wp, oldwin->w_width);
+	    wp->w_vsep_width = oldwin->w_vsep_width;
+	}
+	frp->fr_width = curfrp->fr_width;
+
+	// "new_size" of the current window goes to the new window, use
+	// one row for the status line
+	win_new_height(wp, new_size);
+	int old_status_height = oldwin->w_status_height;
+	if (flags & (WSP_TOP | WSP_BOT))
+	{
+	    int new_fr_height = curfrp->fr_height - new_size
+							  + WINBAR_HEIGHT(wp) ;
+
+	    if (!((flags & WSP_BOT) && p_ls == 0))
+		new_fr_height -= STATUS_HEIGHT;
+	    if (flags & WSP_BOT)
+		frame_add_statusline(curfrp);
+	    frame_new_height(curfrp, new_fr_height, flags & WSP_TOP, FALSE);
+	}
+	else
+	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
+	if (before)	// new window above current one
+	{
+	    wp->w_winrow = oldwin->w_winrow;
+	    wp->w_status_height = STATUS_HEIGHT;
+	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
+	}
+	else		// new window below current one
+	{
+	    wp->w_winrow = oldwin->w_winrow + VISIBLE_HEIGHT(oldwin)
+							       + STATUS_HEIGHT;
+	    wp->w_status_height = old_status_height;
+	    if (!(flags & WSP_BOT))
+		oldwin->w_status_height = STATUS_HEIGHT;
+	}
+	frame_fix_height(wp);
+	frame_fix_height(oldwin);
+    }
+
+    if (flags & (WSP_TOP | WSP_BOT))
+	(void)win_comp_pos();
+
+     // Both windows need redrawing.  Update all status lines, in case they
+     // show something related to the window count or position.
+    redraw_win_later(wp, UPD_NOT_VALID);
+    redraw_win_later(oldwin, UPD_NOT_VALID);
+    status_redraw_all();
+
+    if (need_status)
+    {
+	msg_row = Rows - 1;
+	msg_col = sc_col;
+	msg_clr_eos_force();	// Old command/ruler may still be there
+	comp_col();
+	msg_row = Rows - 1;
+	msg_col = 0;	// put position back at start of line
+    }
+
+    /*
+     * equalize the window sizes.
+     */
+    if (do_equal || dir != 0)
+	win_equal(wp, TRUE,
+		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
+		: dir == 'h' ? 'b' : 'v');
+    else if (!is_aucmd_win(wp))
+	win_fix_scroll(FALSE);
+
+    // Don't change the window height/width to 'winheight' / 'winwidth' if a
+    // size was given.
+    if (flags & WSP_VERT)
+    {
+	i = p_wiw;
+	if (size != 0)
+	    p_wiw = size;
+
+# ifdef FEAT_GUI
+	// When 'guioptions' includes 'L' or 'R' may have to add scrollbars.
+	if (gui.in_use)
+	    gui_init_which_components(NULL);
+# endif
+    }
+    else
+    {
+	i = p_wh;
+	if (size != 0)
+	    p_wh = size;
+    }
+
+    /*
+     * make the new window the current window
+     */
+    (void)win_enter_ext(wp, WEE_TRIGGER_NEW_AUTOCMDS
+		    | WEE_TRIGGER_ENTER_AUTOCMDS | WEE_TRIGGER_LEAVE_AUTOCMDS);
+    if (flags & WSP_VERT)
+	p_wiw = i;
+    else
+	p_wh = i;
+    retval = OK;
+
+theend:
+    if (RedrawingDisabled > 0)
+	--RedrawingDisabled;
+    return retval;
+}
+
+
+/*
+ * Initialize window "newp" from window "oldp".
+ * Used when splitting a window and when creating a new tab page.
+ * The windows will both edit the same buffer.
+ * WSP_NEWLOC may be specified in flags to prevent the location list from
+ * being copied.
+ */
+    static void
+win_init(win_T *newp, win_T *oldp, int flags UNUSED)
+{
+    int		i;
+
+    newp->w_buffer = oldp->w_buffer;
+#ifdef FEAT_SYN_HL
+    newp->w_s = &(oldp->w_buffer->b_s);
+#endif
+    oldp->w_buffer->b_nwindows++;
+    newp->w_cursor = oldp->w_cursor;
+    newp->w_valid = 0;
+    newp->w_curswant = oldp->w_curswant;
+    newp->w_set_curswant = oldp->w_set_curswant;
+    newp->w_topline = oldp->w_topline;
+#ifdef FEAT_DIFF
+    newp->w_topfill = oldp->w_topfill;
+#endif
+    newp->w_leftcol = oldp->w_leftcol;
+    newp->w_pcmark = oldp->w_pcmark;
+    newp->w_prev_pcmark = oldp->w_prev_pcmark;
+    newp->w_alt_fnum = oldp->w_alt_fnum;
+    newp->w_wrow = oldp->w_wrow;
+    newp->w_fraction = oldp->w_fraction;
+    newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
+    copy_jumplist(oldp, newp);
+#ifdef FEAT_QUICKFIX
+    if (flags & WSP_NEWLOC)
+    {
+	// Don't copy the location list.
+	newp->w_llist = NULL;
+	newp->w_llist_ref = NULL;
+    }
+    else
+	copy_loclist_stack(oldp, newp);
+#endif
+    newp->w_localdir = (oldp->w_localdir == NULL)
+				    ? NULL : vim_strsave(oldp->w_localdir);
+    newp->w_prevdir = (oldp->w_prevdir == NULL)
+				    ? NULL : vim_strsave(oldp->w_prevdir);
+
+    if (*p_spk != 'c')
+    {
+	if (*p_spk == 't')
+	    newp->w_skipcol = oldp->w_skipcol;
+	newp->w_botline = oldp->w_botline;
+	newp->w_prev_height = oldp->w_height - WINBAR_HEIGHT(oldp);
+	newp->w_prev_winrow = oldp->w_winrow + 2 * WINBAR_HEIGHT(oldp);
+    }
+
+    // copy tagstack and folds
+    for (i = 0; i < oldp->w_tagstacklen; i++)
+    {
+	taggy_T	*tag = &newp->w_tagstack[i];
+	*tag = oldp->w_tagstack[i];
+	if (tag->tagname != NULL)
+	    tag->tagname = vim_strsave(tag->tagname);
+	if (tag->user_data != NULL)
+	    tag->user_data = vim_strsave(tag->user_data);
+    }
+    newp->w_tagstackidx = oldp->w_tagstackidx;
+    newp->w_tagstacklen = oldp->w_tagstacklen;
+
+    // Keep same changelist position in new window.
+    newp->w_changelistidx = oldp->w_changelistidx;
+
+#ifdef FEAT_FOLDING
+    copyFoldingState(oldp, newp);
+#endif
+
+    win_init_some(newp, oldp);
+#ifdef FEAT_TERMINAL
+    term_update_wincolor(newp);
+#endif
+}
+
+/*
+ * Initialize window "newp" from window "old".
+ * Only the essential things are copied.
+ */
+    static void
+win_init_some(win_T *newp, win_T *oldp)
+{
+    // Use the same argument list.
+    newp->w_alist = oldp->w_alist;
+    ++newp->w_alist->al_refcount;
+    newp->w_arg_idx = oldp->w_arg_idx;
+
+    // copy options from existing window
+    win_copy_options(oldp, newp);
+}
+
+/*
+ * Return TRUE if "win" is a global popup or a popup in the current tab page.
+ */
+    int
+win_valid_popup(win_T *win UNUSED)
+{
+#ifdef FEAT_PROP_POPUP
+    win_T	*wp;
+
+    FOR_ALL_POPUPWINS(wp)
+	if (wp == win)
+	    return TRUE;
+    FOR_ALL_POPUPWINS_IN_TAB(curtab, wp)
+	if (wp == win)
+	    return TRUE;
+#endif
+    return FALSE;
+}
+
+/*
+ * Check if "win" is a pointer to an existing window in the current tab page.
+ */
+    int
+win_valid(win_T *win)
+{
+    win_T	*wp;
+
+    if (win == NULL)
+	return FALSE;
+    FOR_ALL_WINDOWS(wp)
+	if (wp == win)
+	    return TRUE;
+    return win_valid_popup(win);
+}
+
+/*
+ * Find window "id" in the current tab page.
+ * Also find popup windows.
+ * Return NULL if not found.
+ */
+    win_T *
+win_find_by_id(int id)
+{
+    win_T   *wp;
+
+    FOR_ALL_WINDOWS(wp)
+	if (wp->w_id == id)
+	    return wp;
+#ifdef FEAT_PROP_POPUP
+    FOR_ALL_POPUPWINS(wp)
+	if (wp->w_id == id)
+	    return wp;
+    FOR_ALL_POPUPWINS_IN_TAB(curtab, wp)
+	if (wp->w_id == id)
+	    return wp;
+#endif
+    return NULL;
+}
+
+/*
+ * Check if "win" is a pointer to an existing window in any tab page.
+ */
+    int
+win_valid_any_tab(win_T *win)
+{
+    win_T	*wp;
+    tabpage_T	*tp;
+
+    if (win == NULL)
+	return FALSE;
+    FOR_ALL_TABPAGES(tp)
+    {
+	FOR_ALL_WINDOWS_IN_TAB(tp, wp)
+	{
+	    if (wp == win)
+		return TRUE;
+	}
+#ifdef FEAT_PROP_POPUP
+	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
+	    if (wp == win)
+		return TRUE;
+#endif
+    }
+    return win_valid_popup(win);
+}
+
+/*
+ * Return the number of windows.
+ */
+    int
+win_count(void)
+{
+    win_T	*wp;
+    int		count = 0;
+
+    FOR_ALL_WINDOWS(wp)
+	++count;
+    return count;
+}
+
+/*
+ * Make "count" windows on the screen.
+ * Return actual number of windows on the screen.
+ * Must be called when there is just one window, filling the whole screen
+ * (excluding the command line).
+ */
+    int
+make_windows(
+    int		count,
+    int		vertical UNUSED)  // split windows vertically if TRUE
+{
+    int		maxcount;
+    int		todo;
+
+    if (vertical)
+    {
+	// Each window needs at least 'winminwidth' lines and a separator
+	// column.
+	maxcount = (curwin->w_width + curwin->w_vsep_width
+					     - (p_wiw - p_wmw)) / (p_wmw + 1);
+    }
+    else
+    {
+	// Each window needs at least 'winminheight' lines and a status line.
+	maxcount = (VISIBLE_HEIGHT(curwin) + curwin->w_status_height
+				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
+    }
+
+    if (maxcount < 2)
+	maxcount = 2;
+    if (count > maxcount)
+	count = maxcount;
+
+    /*
+     * add status line now, otherwise first window will be too big
+     */
+    if (count > 1)
+	last_status(TRUE);
+
+    /*
+     * Don't execute autocommands while creating the windows.  Must do that
+     * when putting the buffers in the windows.
+     */
+    block_autocmds();
+
+    // todo is number of windows left to create
+    for (todo = count - 1; todo > 0; --todo)
+	if (vertical)
+	{
+	    if (win_split(curwin->w_width - (curwin->w_width - todo)
+			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
+		break;
+	}
+	else
+	{
+	    if (win_split(curwin->w_height - (curwin->w_height - todo
+			    * STATUS_HEIGHT) / (todo + 1)
+			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
+		break;
+	}
+
+    unblock_autocmds();
+
+    // return actual number of windows
+    return (count - todo);
+}
+
+/*
+ * Exchange current and next window
+ */
+    static void
+win_exchange(long Prenum)
+{
+    frame_T	*frp;
+    frame_T	*frp2;
+    win_T	*wp;
+    win_T	*wp2;
+    int		temp;
+
+    if (ERROR_IF_ANY_POPUP_WINDOW)
+	return;
+    if (ONE_WINDOW)	    // just one window
+    {
+	beep_flush();
+	return;
+    }
+    if (text_or_buf_locked())
+    {
+	beep_flush();
+	return;
+    }
+
+#ifdef FEAT_GUI
+    need_mouse_correct = TRUE;
+#endif
+
+    /*
+     * find window to exchange with
+     */
+    if (Prenum)
+    {
+	frp = curwin->w_frame->fr_parent->fr_child;
+	while (frp != NULL && --Prenum > 0)
+	    frp = frp->fr_next;
+    }
+    else if (curwin->w_frame->fr_next != NULL)	// Swap with next
+	frp = curwin->w_frame->fr_next;
+    else    // Swap last window in row/col with previous
+	frp = curwin->w_frame->fr_prev;
+
+    // We can only exchange a window with another window, not with a frame
+    // containing windows.
+    if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
+	return;
+    wp = frp->fr_win;
+
+/*
+ * 1. remove curwin from the list. Remember after which window it was in wp2
+ * 2. insert curwin before wp in the list
+ * if wp != wp2
+ *    3. remove wp from the list
+ *    4. insert wp after wp2
+ * 5. exchange the status line height and vsep width.
+ */
+    wp2 = curwin->w_prev;
+    frp2 = curwin->w_frame->fr_prev;
+    if (wp->w_prev != curwin)
+    {
+	win_remove(curwin, NULL);
+	frame_remove(curwin->w_frame);
+	win_append(wp->w_prev, curwin);
+	frame_insert(frp, curwin->w_frame);
+    }
+    if (wp != wp2)
+    {
+	win_remove(wp, NULL);
+	frame_remove(wp->w_frame);
+	win_append(wp2, wp);
+	if (frp2 == NULL)
+	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
+	else
+	    frame_append(frp2, wp->w_frame);
+    }
+    temp = curwin->w_status_height;
+    curwin->w_status_height = wp->w_status_height;
+    wp->w_status_height = temp;
+    temp = curwin->w_vsep_width;
+    curwin->w_vsep_width = wp->w_vsep_width;
+    wp->w_vsep_width = temp;
+
+    frame_fix_height(curwin);
+    frame_fix_height(wp);
+    frame_fix_width(curwin);
+    frame_fix_width(wp);
+
+    (void)win_comp_pos();		// recompute window positions
+
+    if (wp->w_buffer != curbuf)
+	reset_VIsual_and_resel();
+    else if (VIsual_active)
+	wp->w_cursor = curwin->w_cursor;
+
+    win_enter(wp, TRUE);
+    redraw_all_later(UPD_NOT_VALID);
+}
+
+/*
+ * rotate windows: if upwards TRUE the second window becomes the first one
+ *		   if upwards FALSE the first window becomes the second one
+ */
+    static void
+win_rotate(int upwards, int count)
+{
+    win_T	*wp1;
+    win_T	*wp2;
+    frame_T	*frp;
+    int		n;
+
+    if (ONE_WINDOW)		// nothing to do
+    {
+	beep_flush();
+	return;
+    }
+
+#ifdef FEAT_GUI
+    need_mouse_correct = TRUE;
+#endif
+
+    // Check if all frames in this row/col have one window.
+    FOR_ALL_FRAMES(frp, curwin->w_frame->fr_parent->fr_child)
+	if (frp->fr_win == NULL)
+	{
+	    emsg(_(e_cannot_rotate_when_another_window_is_split));
+	    return;
+	}
+
+    while (count--)
+    {
+	if (upwards)		// first window becomes last window
+	{
+	    // remove first window/frame from the list
+	    frp = curwin->w_frame->fr_parent->fr_child;
+	    wp1 = frp->fr_win;
+	    win_remove(wp1, NULL);
+	    frame_remove(frp);
+
+	    // find last frame and append removed window/frame after it
+	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
+		;
+	    win_append(frp->fr_win, wp1);
+	    frame_append(frp, wp1->w_frame);
+
+	    wp2 = frp->fr_win;		// previously last window
+	}
+	else			// last window becomes first window
+	{
+	    // find last window/frame in the list and remove it
+	    for (frp = curwin->w_frame; frp->fr_next != NULL;
+							   frp = frp->fr_next)
+		;
+	    wp1 = frp->fr_win;
+	    wp2 = wp1->w_prev;		    // will become last window
+	    win_remove(wp1, NULL);
+	    frame_remove(frp);
+
+	    // append the removed window/frame before the first in the list
+	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
+	    frame_insert(frp->fr_parent->fr_child, frp);
+	}
+
+	// exchange status height and vsep width of old and new last window
+	n = wp2->w_status_height;
+	wp2->w_status_height = wp1->w_status_height;
+	wp1->w_status_height = n;
+	frame_fix_height(wp1);
+	frame_fix_height(wp2);
+	n = wp2->w_vsep_width;
+	wp2->w_vsep_width = wp1->w_vsep_width;
+	wp1->w_vsep_width = n;
+	frame_fix_width(wp1);
+	frame_fix_width(wp2);
+
+	// recompute w_winrow and w_wincol for all windows
+	(void)win_comp_pos();
+    }
+
+    redraw_all_later(UPD_NOT_VALID);
+}
+
+/*
+ * Move the current window to the very top/bottom/left/right of the screen.
+ */
+    static void
+win_totop(int size, int flags)
+{
+    int		dir;
+    int		height = curwin->w_height;
+
+    if (ONE_WINDOW)
+    {
+	beep_flush();
+	return;
+    }
+    if (check_split_disallowed() == FAIL)
+	return;
+
+    // Remove the window and frame from the tree of frames.
+    (void)winframe_remove(curwin, &dir, NULL);
+    win_remove(curwin, NULL);
+    last_status(FALSE);	    // may need to remove last status line
+    (void)win_comp_pos();   // recompute window positions
+
+    // Split a window on the desired side and put the window there.
+    (void)win_split_ins(size, flags, curwin, dir);
+    if (!(flags & WSP_VERT))
+    {
+	win_setheight(height);
+	if (p_ea)
+	    win_equal(curwin, TRUE, 'v');
+    }
+
+#if defined(FEAT_GUI)
+    // When 'guioptions' includes 'L' or 'R' may have to remove or add
+    // scrollbars.  Have to update them anyway.
+    gui_may_update_scrollbars();
+#endif
+}
+
+/*
+ * Move window "win1" to below/right of "win2" and make "win1" the current
+ * window.  Only works within the same frame!
+ */
+    void
+win_move_after(win_T *win1, win_T *win2)
+{
+    int		height;
+
+    // check if the arguments are reasonable
+    if (win1 == win2)
+	return;
+
+    // check if there is something to do
+    if (win2->w_next != win1)
+    {
+	if (win1->w_frame->fr_parent != win2->w_frame->fr_parent)
+	{
+	    iemsg("Trying to move a window into another frame");
+	    return;
+	}
+
+	// may need to move the status line/vertical separator of the last
+	// window
+	if (win1 == lastwin)
+	{
+	    height = win1->w_prev->w_status_height;
+	    win1->w_prev->w_status_height = win1->w_status_height;
+	    win1->w_status_height = height;
+	    if (win1->w_prev->w_vsep_width == 1)
+	    {
+		// Remove the vertical separator from the last-but-one window,
+		// add it to the last window.  Adjust the frame widths.
+		win1->w_prev->w_vsep_width = 0;
+		win1->w_prev->w_frame->fr_width -= 1;
+		win1->w_vsep_width = 1;
+		win1->w_frame->fr_width += 1;
+	    }
+	}
+	else if (win2 == lastwin)
+	{
+	    height = win1->w_status_height;
+	    win1->w_status_height = win2->w_status_height;
+	    win2->w_status_height = height;
+	    if (win1->w_vsep_width == 1)
+	    {
+		// Remove the vertical separator from win1, add it to the last
+		// window, win2.  Adjust the frame widths.
+		win2->w_vsep_width = 1;
+		win2->w_frame->fr_width += 1;
+		win1->w_vsep_width = 0;
+		win1->w_frame->fr_width -= 1;
+	    }
+	}
+	win_remove(win1, NULL);
+	frame_remove(win1->w_frame);
+	win_append(win2, win1);
+	frame_append(win2->w_frame, win1->w_frame);
+
+	(void)win_comp_pos();	// recompute w_winrow for all windows
+	redraw_later(UPD_NOT_VALID);
+    }
+    win_enter(win1, FALSE);
+}
+
+/*
+ * Make all windows the same height.
+ * 'next_curwin' will soon be the current window, make sure it has enough
+ * rows.
+ */
+    void
+win_equal(
+    win_T	*next_curwin,	// pointer to current window to be or NULL
+    int		current,	// do only frame with current window
+    int		dir)		// 'v' for vertically, 'h' for horizontally,
+				// 'b' for both, 0 for using p_ead
+{
+    if (dir == 0)
+	dir = *p_ead;
+    win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
+		      topframe, dir, 0, tabline_height(),
+					   (int)Columns, topframe->fr_height);
+    if (!is_aucmd_win(next_curwin))
+	win_fix_scroll(TRUE);
+}
+
+/*
+ * Set a frame to a new position and height, spreading the available room
+ * equally over contained frames.
+ * The window "next_curwin" (if not NULL) should at least get the size from
+ * 'winheight' and 'winwidth' if possible.
+ */
+    static void
+win_equal_rec(
+    win_T	*next_curwin,	// pointer to current window to be or NULL
+    int		current,	// do only frame with current window
+    frame_T	*topfr,		// frame to set size off
+    int		dir,		// 'v', 'h' or 'b', see win_equal()
+    int		col,		// horizontal position for frame
+    int		row,		// vertical position for frame
+    int		width,		// new width of frame
+    int		height)		// new height of frame
+{
+    int		n, m;
+    int		extra_sep = 0;
+    int		wincount, totwincount = 0;
+    frame_T	*fr;
+    int		next_curwin_size = 0;
+    int		room = 0;
+    int		new_size;
+    int		has_next_curwin = 0;
+    int		hnc;
+
+    if (topfr->fr_layout == FR_LEAF)
+    {
+	// Set the width/height of this frame.
+	// Redraw when size or position changes
+	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
+		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
+	   )
+	{
+	    topfr->fr_win->w_winrow = row;
+	    frame_new_height(topfr, height, FALSE, FALSE);
+	    topfr->fr_win->w_wincol = col;
+	    frame_new_width(topfr, width, FALSE, FALSE);
+	    redraw_all_later(UPD_NOT_VALID);
+	}
+    }
+    else if (topfr->fr_layout == FR_ROW)
+    {
+	topfr->fr_width = width;
+	topfr->fr_height = height;
+
+	if (dir != 'v')			// equalize frame widths
+	{
+	    // Compute the maximum number of windows horizontally in this
+	    // frame.
+	    n = frame_minwidth(topfr, NOWIN);
+	    // add one for the rightmost window, it doesn't have a separator
+	    if (col + width == Columns)
+		extra_sep = 1;
+	    else
+		extra_sep = 0;
+	    totwincount = (n + extra_sep) / (p_wmw + 1);
+	    has_next_curwin = frame_has_win(topfr, next_curwin);
+
+	    /*
+	     * Compute width for "next_curwin" window and room available for
+	     * other windows.
+	     * "m" is the minimal width when counting p_wiw for "next_curwin".
+	     */
+	    m = frame_minwidth(topfr, next_curwin);
+	    room = width - m;
+	    if (room < 0)
+	    {
+		next_curwin_size = p_wiw + room;
+		room = 0;
+	    }
+	    else
+	    {
+		next_curwin_size = -1;
+		FOR_ALL_FRAMES(fr, topfr->fr_child)
+		{
+		    if (!frame_fixed_width(fr))
+			continue;
+		    // If 'winfixwidth' set keep the window width if possible.
+		    // Watch out for this window being the next_curwin.
+		    n = frame_minwidth(fr, NOWIN);
+		    new_size = fr->fr_width;
+		    if (frame_has_win(fr, next_curwin))
+		    {
+			room += p_wiw - p_wmw;
+			next_curwin_size = 0;
+			if (new_size < p_wiw)
+			    new_size = p_wiw;
+		    }
+		    else
+			// These windows don't use up room.
+			totwincount -= (n + (fr->fr_next == NULL
+					       ? extra_sep : 0)) / (p_wmw + 1);
+		    room -= new_size - n;
+		    if (room < 0)
+		    {
+			new_size += room;
+			room = 0;
+		    }
+		    fr->fr_newwidth = new_size;
+		}
+		if (next_curwin_size == -1)
+		{
+		    if (!has_next_curwin)
+			next_curwin_size = 0;
+		    else if (totwincount > 1
+			    && (room + (totwincount - 2))
+						  / (totwincount - 1) > p_wiw)
+		    {
+			// Can make all windows wider than 'winwidth', spread
+			// the room equally.
+			next_curwin_size = (room + p_wiw
+					    + (totwincount - 1) * p_wmw
+					    + (totwincount - 1)) / totwincount;
+			room -= next_curwin_size - p_wiw;
+		    }
+		    else
+			next_curwin_size = p_wiw;
+		}
+	    }
+
+	    if (has_next_curwin)
+		--totwincount;		// don't count curwin
+	}
+
+	FOR_ALL_FRAMES(fr, topfr->fr_child)
+	{
+	    wincount = 1;
+	    if (fr->fr_next == NULL)
+		// last frame gets all that remains (avoid roundoff error)
+		new_size = width;
+	    else if (dir == 'v')
+		new_size = fr->fr_width;
+	    else if (frame_fixed_width(fr))
+	    {
+		new_size = fr->fr_newwidth;
+		wincount = 0;	    // doesn't count as a sizeable window
+	    }
+	    else
+	    {
+		// Compute the maximum number of windows horiz. in "fr".
+		n = frame_minwidth(fr, NOWIN);
+		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
+								/ (p_wmw + 1);
+		m = frame_minwidth(fr, next_curwin);
+		if (has_next_curwin)
+		    hnc = frame_has_win(fr, next_curwin);
+		else
+		    hnc = FALSE;
+		if (hnc)	    // don't count next_curwin
+		    --wincount;
+		if (totwincount == 0)
+		    new_size = room;
+		else
+		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
+								/ totwincount;
+		if (hnc)	    // add next_curwin size
+		{
+		    next_curwin_size -= p_wiw - (m - n);
+		    if (next_curwin_size < 0)
+			next_curwin_size = 0;
+		    new_size += next_curwin_size;
+		    room -= new_size - next_curwin_size;
+		}
+		else
+		    room -= new_size;
+		new_size += n;
+	    }
+
+	    // Skip frame that is full width when splitting or closing a
+	    // window, unless equalizing all frames.
+	    if (!current || dir != 'v' || topfr->fr_parent != NULL
+		    || (new_size != fr->fr_width)
+		    || frame_has_win(fr, next_curwin))
+		win_equal_rec(next_curwin, current, fr, dir, col, row,
+							    new_size, height);
+	    col += new_size;
+	    width -= new_size;
+	    totwincount -= wincount;
+	}
+    }
+    else // topfr->fr_layout == FR_COL
+    {
+	topfr->fr_width = width;
+	topfr->fr_height = height;
+
+	if (dir != 'h')			// equalize frame heights
+	{
+	    // Compute maximum number of windows vertically in this frame.
+	    n = frame_minheight(topfr, NOWIN);
+	    // add one for the bottom window if it doesn't have a statusline
+	    if (row + height == cmdline_row && p_ls == 0)
+		extra_sep = 1;
+	    else
+		extra_sep = 0;
+	    totwincount = (n + extra_sep) / (p_wmh + 1);
+	    has_next_curwin = frame_has_win(topfr, next_curwin);
+
+	    /*
+	     * Compute height for "next_curwin" window and room available for
+	     * other windows.
+	     * "m" is the minimal height when counting p_wh for "next_curwin".
+	     */
+	    m = frame_minheight(topfr, next_curwin);
+	    room = height - m;
+	    if (room < 0)
+	    {
+		// The room is less than 'winheight', use all space for the
+		// current window.
+		next_curwin_size = p_wh + room;
+		room = 0;
+	    }
+	    else
+	    {
+		next_curwin_size = -1;
+		FOR_ALL_FRAMES(fr, topfr->fr_child)
+		{
+		    if (!frame_fixed_height(fr))
+			continue;
+		    // If 'winfixheight' set keep the window height if
+		    // possible.
+		    // Watch out for this window being the next_curwin.
+		    n = frame_minheight(fr, NOWIN);
+		    new_size = fr->fr_height;
+		    if (frame_has_win(fr, next_curwin))
+		    {
+			room += p_wh - p_wmh;
+			next_curwin_size = 0;
+			if (new_size < p_wh)
+			    new_size = p_wh;
+		    }
+		    else
+			// These windows don't use up room.
+			totwincount -= (n + (fr->fr_next == NULL
+					       ? extra_sep : 0)) / (p_wmh + 1);
+		    room -= new_size - n;
+		    if (room < 0)
+		    {
+			new_size += room;
+			room = 0;
+		    }
+		    fr->fr_newheight = new_size;
+		}
+		if (next_curwin_size == -1)
+		{
+		    if (!has_next_curwin)
+			next_curwin_size = 0;
+		    else if (totwincount > 1
+			    && (room + (totwincount - 2))
+						   / (totwincount - 1) > p_wh)
+		    {
+			// can make all windows higher than 'winheight',
+			// spread the room equally.
+			next_curwin_size = (room + p_wh
+					   + (totwincount - 1) * p_wmh
+					   + (totwincount - 1)) / totwincount;
+			room -= next_curwin_size - p_wh;
+		    }
+		    else
+			next_curwin_size = p_wh;
+		}
+	    }
+
+	    if (has_next_curwin)
+		--totwincount;		// don't count curwin
+	}
+
+	FOR_ALL_FRAMES(fr, topfr->fr_child)
+	{
+	    wincount = 1;
+	    if (fr->fr_next == NULL)
+		// last frame gets all that remains (avoid roundoff error)
+		new_size = height;
+	    else if (dir == 'h')
+		new_size = fr->fr_height;
+	    else if (frame_fixed_height(fr))
+	    {
+		new_size = fr->fr_newheight;
+		wincount = 0;	    // doesn't count as a sizeable window
+	    }
+	    else
+	    {
+		// Compute the maximum number of windows vert. in "fr".
+		n = frame_minheight(fr, NOWIN);
+		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
+								/ (p_wmh + 1);
+		m = frame_minheight(fr, next_curwin);
+		if (has_next_curwin)
+		    hnc = frame_has_win(fr, next_curwin);
+		else
+		    hnc = FALSE;
+		if (hnc)	    // don't count next_curwin
+		    --wincount;
+		if (totwincount == 0)
+		    new_size = room;
+		else
+		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
+								/ totwincount;
+		if (hnc)	    // add next_curwin size
+		{
+		    next_curwin_size -= p_wh - (m - n);
+		    new_size += next_curwin_size;
+		    room -= new_size - next_curwin_size;
+		}
+		else
+		    room -= new_size;
+		new_size += n;
+	    }
+	    // Skip frame that is full width when splitting or closing a
+	    // window, unless equalizing all frames.
+	    if (!current || dir != 'h' || topfr->fr_parent != NULL
+		    || (new_size != fr->fr_height)
+		    || frame_has_win(fr, next_curwin))
+		win_equal_rec(next_curwin, current, fr, dir, col, row,
+							     width, new_size);
+	    row += new_size;
+	    height -= new_size;
+	    totwincount -= wincount;
+	}
+    }
+}
+
+#ifdef FEAT_JOB_CHANNEL
+    void
+leaving_window(win_T *win)
+{
+    // Only matters for a prompt window.
+    if (!bt_prompt(win->w_buffer))
+	return;
+
+    // When leaving a prompt window stop Insert mode and perhaps restart
+    // it when entering that window again.
+    win->w_buffer->b_prompt_insert = restart_edit;
+    if (restart_edit != 0 && mode_displayed)
+	clear_cmdline = TRUE;		// unshow mode later
+    restart_edit = NUL;
+
+    // When leaving the window (or closing the window) was done from a
+    // callback we need to break out of the Insert mode loop and restart Insert
+    // mode when entering the window again.
+    if (State & MODE_INSERT)
+    {
+	stop_insert_mode = TRUE;
+	if (win->w_buffer->b_prompt_insert == NUL)
+	    win->w_buffer->b_prompt_insert = 'A';
+    }
+}
+
+    void
+entering_window(win_T *win)
+{
+    // Only matters for a prompt window.
+    if (!bt_prompt(win->w_buffer))
+	return;
+
+    // When switching to a prompt buffer that was in Insert mode, don't stop
+    // Insert mode, it may have been set in leaving_window().
+    if (win->w_buffer->b_prompt_insert != NUL)
+	stop_insert_mode = FALSE;
+
+    // When entering the prompt window restart Insert mode if we were in Insert
+    // mode when we left it and not already in Insert mode.
+    if ((State & MODE_INSERT) == 0)
+	restart_edit = win->w_buffer->b_prompt_insert;
+}
+#endif
+
+    static void
+win_init_empty(win_T *wp)
+{
+    redraw_win_later(wp, UPD_NOT_VALID);
+    wp->w_lines_valid = 0;
+    wp->w_cursor.lnum = 1;
+    wp->w_curswant = wp->w_cursor.col = 0;
+    wp->w_cursor.coladd = 0;
+    wp->w_pcmark.lnum = 1;	// pcmark not cleared but set to line 1
+    wp->w_pcmark.col = 0;
+    wp->w_prev_pcmark.lnum = 0;
+    wp->w_prev_pcmark.col = 0;
+    wp->w_topline = 1;
+#ifdef FEAT_DIFF
+    wp->w_topfill = 0;
+#endif
+    wp->w_botline = 2;
+#if defined(FEAT_SYN_HL) || defined(FEAT_SPELL)
+    wp->w_s = &wp->w_buffer->b_s;
+#endif
+#ifdef FEAT_TERMINAL
+    term_reset_wincolor(wp);
+#endif
+}
+
+/*
+ * Init the current window "curwin".
+ * Called when a new file is being edited.
+ */
+    void
+curwin_init(void)
+{
+    win_init_empty(curwin);
+}
+
+/*
+ * Close all windows for buffer "buf".
+ */
+    void
+close_windows(
+    buf_T	*buf,
+    int		keep_curwin)	    // don't close "curwin"
+{
+    win_T	*wp;
+    tabpage_T   *tp, *nexttp;
+    int		count = tabpage_index(NULL);
+
+    ++RedrawingDisabled;
+
+    for (wp = firstwin; wp != NULL && !ONE_WINDOW; )
+    {
+	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
+		&& !(wp->w_closing || wp->w_buffer->b_locked > 0))
+	{
+	    if (win_close(wp, FALSE) == FAIL)
+		// If closing the window fails give up, to avoid looping
+		// forever.
+		break;
+
+	    // Start all over, autocommands may change the window layout.
+	    wp = firstwin;
+	}
+	else
+	    wp = wp->w_next;
+    }
+
+    // Also check windows in other tab pages.
+    for (tp = first_tabpage; tp != NULL; tp = nexttp)
+    {
+	nexttp = tp->tp_next;
+	if (tp != curtab)
+	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
+		if (wp->w_buffer == buf
+		    && !(wp->w_closing || wp->w_buffer->b_locked > 0))
+		{
+		    win_close_othertab(wp, FALSE, tp);
+
+		    // Start all over, the tab page may be closed and
+		    // autocommands may change the window layout.
+		    nexttp = first_tabpage;
+		    break;
+		}
+    }
+
+    if (RedrawingDisabled > 0)
+	--RedrawingDisabled;
+
+    if (count != tabpage_index(NULL))
+	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
+}
+
+/*
+ * Return TRUE if the current window is the only window that exists (ignoring
+ * "aucmd_win[]").
+ * Returns FALSE if there is a window, possibly in another tab page.
+ */
+    static int
+last_window(void)
+{
+    return (one_window() && first_tabpage->tp_next == NULL);
+}
+
+/*
+ * Return TRUE if there is only one window other than "aucmd_win[]" in the
+ * current tab page.
+ */
+    int
+one_window(void)
+{
+    win_T	*wp;
+    int		seen_one = FALSE;
+
+    FOR_ALL_WINDOWS(wp)
+    {
+	if (!is_aucmd_win(wp))
+	{
+	    if (seen_one)
+		return FALSE;
+	    seen_one = TRUE;
+	}
+    }
+    return TRUE;
+}
+
+/*
+ * Close the possibly last window in a tab page.
+ * Returns TRUE when the window was closed already.
+ */
+    static int
+close_last_window_tabpage(
+    win_T	*win,
+    int		free_buf,
+    tabpage_T   *prev_curtab)
+{
+    if (!ONE_WINDOW)
+	return FALSE;
+
+    buf_T	*old_curbuf = curbuf;
+
+    /*
+     * Closing the last window in a tab page.  First go to another tab
+     * page and then close the window and the tab page.  This avoids that
+     * curwin and curtab are invalid while we are freeing memory, they may
+     * be used in GUI events.
+     * Don't trigger autocommands yet, they may use wrong values, so do
+     * that below.
+     */
+    goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
+
+    // Safety check: Autocommands may have closed the window when jumping
+    // to the other tab page.
+    if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
+	win_close_othertab(win, free_buf, prev_curtab);
+#ifdef FEAT_JOB_CHANNEL
+    entering_window(curwin);
+#endif
+    // Since goto_tabpage_tp above did not trigger *Enter autocommands, do
+    // that now.
+    apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
+    apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
+    apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
+    if (old_curbuf != curbuf)
+	apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
+    return TRUE;
+}
+
+/*
+ * Close the buffer of "win" and unload it if "action" is DOBUF_UNLOAD.
+ * "action" can also be zero (do nothing) or DOBUF_WIPE.
+ * "abort_if_last" is passed to close_buffer(): abort closing if all other
+ * windows are closed.
+ */
+    static void
+win_close_buffer(win_T *win, int action, int abort_if_last)
+{
+#ifdef FEAT_SYN_HL
+    // Free independent synblock before the buffer is freed.
+    if (win->w_buffer != NULL)
+	reset_synblock(win);
+#endif
+
+#ifdef FEAT_QUICKFIX
+    // When a quickfix/location list window is closed and the buffer is
+    // displayed in only one window, then unlist the buffer.
+    if (win->w_buffer != NULL && bt_quickfix(win->w_buffer)
+					&& win->w_buffer->b_nwindows == 1)
+	win->w_buffer->b_p_bl = FALSE;
+#endif
+
+    // Close the link to the buffer.
+    if (win->w_buffer != NULL)
+    {
+	bufref_T    bufref;
+
+	set_bufref(&bufref, curbuf);
+	win->w_closing = TRUE;
+	close_buffer(win, win->w_buffer, action, abort_if_last, TRUE);
+	if (win_valid_any_tab(win))
+	    win->w_closing = FALSE;
+	// Make sure curbuf is valid. It can become invalid if 'bufhidden' is
+	// "wipe".
+	if (!bufref_valid(&bufref))
+	    curbuf = firstbuf;
+    }
+}
+
+/*
+ * Close window "win".  Only works for the current tab page.
+ * If "free_buf" is TRUE related buffer may be unloaded.
+ *
+ * Called by :quit, :close, :xit, :wq and findtag().
+ * Returns FAIL when the window was not closed.
+ */
+    int
+win_close(win_T *win, int free_buf)
+{
+    win_T	*wp;
+    int		other_buffer = FALSE;
+    int		close_curwin = FALSE;
+    int		dir;
+    int		help_window = FALSE;
+    tabpage_T   *prev_curtab = curtab;
+    frame_T	*win_frame = win->w_frame->fr_parent;
+#ifdef FEAT_DIFF
+    int		had_diffmode = win->w_p_diff;
+#endif
+#ifdef MESSAGE_QUEUE
+    int		did_decrement = FALSE;
+#endif
+
+#if defined(FEAT_TERMINAL) && defined(FEAT_PROP_POPUP)
+    // Can close a popup window with a terminal if the job has finished.
+    if (may_close_term_popup() == OK)
+	return OK;
+#endif
+    if (ERROR_IF_ANY_POPUP_WINDOW)
+	return FAIL;
+
+    if (last_window())
+    {
+	emsg(_(e_cannot_close_last_window));
+	return FAIL;
+    }
+    if (window_layout_locked(CMD_close))
+	return FAIL;
+
+    if (win->w_closing || (win->w_buffer != NULL
+					       && win->w_buffer->b_locked > 0))
+	return FAIL; // window is already being closed
+    if (win_unlisted(win))
+    {
+	emsg(_(e_cannot_close_autocmd_or_popup_window));
+	return FAIL;
+    }
+    if ((is_aucmd_win(firstwin) || is_aucmd_win(lastwin)) && one_window())
+    {
+	emsg(_(e_cannot_close_window_only_autocmd_window_would_remain));
+	return FAIL;
+    }
+
+    // When closing the last window in a tab page first go to another tab page
+    // and then close the window and the tab page to avoid that curwin and
+    // curtab are invalid while we are freeing memory.
+    if (close_last_window_tabpage(win, free_buf, prev_curtab))
+      return FAIL;
+
+    // When closing the help window, try restoring a snapshot after closing
+    // the window.  Otherwise clear the snapshot, it's now invalid.
+    if (bt_help(win->w_buffer))
+	help_window = TRUE;
+    else
+	clear_snapshot(curtab, SNAP_HELP_IDX);
+
+    if (win == curwin)
+    {
+#ifdef FEAT_JOB_CHANNEL
+	leaving_window(curwin);
+#endif
+	/*
+	 * Guess which window is going to be the new current window.
+	 * This may change because of the autocommands (sigh).
+	 */
+	wp = frame2win(win_altframe(win, NULL));
+
+	/*
+	 * Be careful: If autocommands delete the window or cause this window
+	 * to be the last one left, return now.
+	 */
+	if (wp->w_buffer != curbuf)
+	{
+	    reset_VIsual_and_resel();	// stop Visual mode
+
+	    other_buffer = TRUE;
+	    if (!win_valid(win))
+		return FAIL;
+	    win->w_closing = TRUE;
+	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
+	    if (!win_valid(win))
+		return FAIL;
+	    win->w_closing = FALSE;
+	    if (last_window())
+		return FAIL;
+	}
+	win->w_closing = TRUE;
+	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
+	if (!win_valid(win))
+	    return FAIL;
+	win->w_closing = FALSE;
+	if (last_window())
+	    return FAIL;
+#ifdef FEAT_EVAL
+	// autocmds may abort script processing
+	if (aborting())
+	    return FAIL;
+#endif
+    }
+
+#ifdef FEAT_GUI
+    // Avoid trouble with scrollbars that are going to be deleted in
+    // win_free().
+    if (gui.in_use)
+	out_flush();
+#endif
+
+#ifdef FEAT_PROP_POPUP
+    if (popup_win_closed(win) && !win_valid(win))
+	return FAIL;
+#endif
+
+    // Trigger WinClosed just before starting to free window-related resources.
+    trigger_winclosed(win);
+    // autocmd may have freed the window already.
+    if (!win_valid_any_tab(win))
+	return OK;
+
+    win_close_buffer(win, free_buf ? DOBUF_UNLOAD : 0, TRUE);
+
+    if (only_one_window() && win_valid(win) && win->w_buffer == NULL
+	    && (last_window() || curtab != prev_curtab
+		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
+    {
+	// Autocommands have closed all windows, quit now.  Restore
+	// curwin->w_buffer, otherwise writing viminfo may fail.
+	if (curwin->w_buffer == NULL)
+	    curwin->w_buffer = curbuf;
+	getout(0);
+    }
+
+    // Autocommands may have moved to another tab page.
+    if (curtab != prev_curtab && win_valid_any_tab(win)
+						      && win->w_buffer == NULL)
+    {
+	// Need to close the window anyway, since the buffer is NULL.
+	// Don't trigger autocmds with a NULL buffer.
+	block_autocmds();
+	win_close_othertab(win, FALSE, prev_curtab);
+	unblock_autocmds();
+	return FAIL;
+    }
+
+    // Autocommands may have closed the window already or closed the only
+    // other window.
+    if (!win_valid(win) || last_window()
+	    || close_last_window_tabpage(win, free_buf, prev_curtab))
+	return FAIL;
+
+    // Now we are really going to close the window.  Disallow any autocommand
+    // to split a window to avoid trouble.
+    // Also bail out of parse_queued_messages() to avoid it tries to update the
+    // screen.
+    ++split_disallowed;
+#ifdef MESSAGE_QUEUE
+    ++dont_parse_messages;
+#endif
+
+    // Free the memory used for the window and get the window that received
+    // the screen space.
+    wp = win_free_mem(win, &dir, NULL);
+
+    if (help_window)
+    {
+	// Closing the help window moves the cursor back to the current window
+	// of the snapshot.
+	win_T *prev_win = get_snapshot_curwin(SNAP_HELP_IDX);
+
+	if (win_valid(prev_win))
+	    wp = prev_win;
+    }
+
+    // Make sure curwin isn't invalid.  It can cause severe trouble when
+    // printing an error message.  For win_equal() curbuf needs to be valid
+    // too.
+    if (win == curwin)
+    {
+	curwin = wp;
+#ifdef FEAT_QUICKFIX
+	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
+	{
+	    /*
+	     * If the cursor goes to the preview or the quickfix window, try
+	     * finding another window to go to.
+	     */
+	    for (;;)
+	    {
+		if (wp->w_next == NULL)
+		    wp = firstwin;
+		else
+		    wp = wp->w_next;
+		if (wp == curwin)
+		    break;
+		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
+		{
+		    curwin = wp;
+		    break;
+		}
+	    }
+	}
+#endif
+	curbuf = curwin->w_buffer;
+	close_curwin = TRUE;
+
+	// The cursor position may be invalid if the buffer changed after last
+	// using the window.
+	check_cursor();
+    }
+
+    /*
+     * If last window has a status line now and we don't want one, remove the
+     * status line.  Do this before win_equal(), because it may change the
+     * height of a window
+     */
+    last_status(FALSE);
+
+    if (p_ea && (*p_ead == 'b' || *p_ead == dir))
+	// If the frame of the closed window contains the new current window,
+	// only resize that frame.  Otherwise resize all windows.
+	win_equal(curwin, curwin->w_frame->fr_parent == win_frame, dir);
+    else
+    {
+	win_comp_pos();
+	win_fix_scroll(FALSE);
+    }
+    if (close_curwin)
+    {
+	// Pass WEE_ALLOW_PARSE_MESSAGES to decrement dont_parse_messages
+	// before autocommands.
+#ifdef MESSAGE_QUEUE
+	did_decrement =
+#else
+	(void)
+#endif
+	    win_enter_ext(wp,
+		WEE_CURWIN_INVALID | WEE_TRIGGER_ENTER_AUTOCMDS
+		      | WEE_TRIGGER_LEAVE_AUTOCMDS | WEE_ALLOW_PARSE_MESSAGES);
+	if (other_buffer)
+	    // careful: after this wp and win may be invalid!
+	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
+    }
+
+    --split_disallowed;
+#ifdef MESSAGE_QUEUE
+    if (!did_decrement)
+	--dont_parse_messages;
+#endif
+
+    // After closing the help window, try restoring the window layout from
+    // before it was opened.
+    if (help_window)
+	restore_snapshot(SNAP_HELP_IDX, close_curwin);
+
+#ifdef FEAT_DIFF
+    // If the window had 'diff' set and now there is only one window left in
+    // the tab page with 'diff' set, and "closeoff" is in 'diffopt', then
+    // execute ":diffoff!".
+    if (diffopt_closeoff() && had_diffmode && curtab == prev_curtab)
+    {
+	int	diffcount = 0;
+	win_T	*dwin;
+
+	FOR_ALL_WINDOWS(dwin)
+	    if (dwin->w_p_diff)
+		++diffcount;
+	if (diffcount == 1)
+	    do_cmdline_cmd((char_u *)"diffoff!");
+    }
+#endif
+
+#if defined(FEAT_GUI)
+    // When 'guioptions' includes 'L' or 'R' may have to remove scrollbars.
+    if (gui.in_use && !win_hasvertsplit())
+	gui_init_which_components(NULL);
+#endif
+
+    redraw_all_later(UPD_NOT_VALID);
+    return OK;
+}
+
+    static void
+trigger_winclosed(win_T *win)
+{
+    static int	recursive = FALSE;
+    char_u	winid[NUMBUFLEN];
+
+    if (recursive)
+	return;
+    recursive = TRUE;
+    vim_snprintf((char *)winid, sizeof(winid), "%d", win->w_id);
+    apply_autocmds(EVENT_WINCLOSED, winid, winid, FALSE, win->w_buffer);
+    recursive = FALSE;
+}
+
+/*
+ * Make a snapshot of all the window scroll positions and sizes of the current
+ * tab page.
+ */
+    void
+snapshot_windows_scroll_size(void)
+{
+    win_T *wp;
+    FOR_ALL_WINDOWS(wp)
+    {
+	wp->w_last_topline = wp->w_topline;
+#ifdef FEAT_DIFF
+	wp->w_last_topfill = wp->w_topfill;
+#endif
+	wp->w_last_leftcol = wp->w_leftcol;
+	wp->w_last_skipcol = wp->w_skipcol;
+	wp->w_last_width = wp->w_width;
+	wp->w_last_height = wp->w_height;
+    }
+}
+
+static int did_initial_scroll_size_snapshot = FALSE;
+
+    void
+may_make_initial_scroll_size_snapshot(void)
+{
+    if (!did_initial_scroll_size_snapshot)
+    {
+	did_initial_scroll_size_snapshot = TRUE;
+	snapshot_windows_scroll_size();
+    }
+}
+
+#ifdef FEAT_EVAL
+/*
+ * Create a dictionary with information about size and scroll changes in a
+ * window.
+ * Returns the dictionary with refcount set to one.
+ * Returns NULL when out of memory.
+ */
+    static dict_T *
+make_win_info_dict(
+	int width,
+	int height,
+	int topline,
+# ifdef FEAT_DIFF
+	int topfill,
+# endif
+	int leftcol,
+	int skipcol)
+{
+    dict_T *d = dict_alloc();
+    if (d == NULL)
+	return NULL;
+    d->dv_refcount = 1;
+
+    // not actually looping, for breaking out on error
+    while (1)
+    {
+	typval_T tv;
+	tv.v_lock = 0;
+	tv.v_type = VAR_NUMBER;
+
+	tv.vval.v_number = width;
+	if (dict_add_tv(d, "width", &tv) == FAIL)
+	    break;
+	tv.vval.v_number = height;
+	if (dict_add_tv(d, "height", &tv) == FAIL)
+	    break;
+	tv.vval.v_number = topline;
+	if (dict_add_tv(d, "topline", &tv) == FAIL)
+	    break;
+#ifdef FEAT_DIFF
+	tv.vval.v_number = topfill;
+#else
+	tv.vval.v_number = 0;
+#endif
+	if (dict_add_tv(d, "topfill", &tv) == FAIL)
+	    break;
+	tv.vval.v_number = leftcol;
+	if (dict_add_tv(d, "leftcol", &tv) == FAIL)
+	    break;
+	tv.vval.v_number = skipcol;
+	if (dict_add_tv(d, "skipcol", &tv) == FAIL)
+	    break;
+	return d;
+    }
+    dict_unref(d);
+    return NULL;
+}
+#endif
+
+// Return values of check_window_scroll_resize():
+#define CWSR_SCROLLED	1  // at least one window scrolled
+#define CWSR_RESIZED	2  // at least one window size changed
+
+/*
+ * This function is used for three purposes:
+ * 1. Goes over all windows in the current tab page and returns:
+ *	0				no scrolling and no size changes found
+ *	CWSR_SCROLLED			at least one window scrolled
+ *	CWSR_RESIZED			at least one window changed size
+ *	CWSR_SCROLLED + CWSR_RESIZED	both
+ *    "size_count" is set to the nr of windows with size changes.
+ *    "first_scroll_win" is set to the first window with any relevant changes.
+ *    "first_size_win" is set to the first window with size changes.
+ *
+ * 2. When the first three arguments are NULL and "winlist" is not NULL,
+ *    "winlist" is set to the list of window IDs with size changes.
+ *
+ * 3. When the first three arguments are NULL and "v_event" is not NULL,
+ *    information about changed windows is added to "v_event".
+ */
+    static int
+check_window_scroll_resize(
+	int	*size_count,
+	win_T	**first_scroll_win,
+	win_T	**first_size_win,
+	list_T	*winlist UNUSED,
+	dict_T	*v_event UNUSED)
+{
+    int result = 0;
+#ifdef FEAT_EVAL
+    int listidx = 0;
+    int tot_width = 0;
+    int tot_height = 0;
+    int tot_topline = 0;
+# ifdef FEAT_DIFF
+    int tot_topfill = 0;
+# endif
+    int tot_leftcol = 0;
+    int tot_skipcol = 0;
+#endif
+
+    win_T *wp;
+    FOR_ALL_WINDOWS(wp)
+    {
+	int size_changed = wp->w_last_width != wp->w_width
+					  || wp->w_last_height != wp->w_height;
+	if (size_changed)
+	{
+	    result |= CWSR_RESIZED;
+#ifdef FEAT_EVAL
+	    if (winlist != NULL)
+	    {
+		// Add this window to the list of changed windows.
+		typval_T tv;
+		tv.v_lock = 0;
+		tv.v_type = VAR_NUMBER;
+		tv.vval.v_number = wp->w_id;
+		list_set_item(winlist, listidx++, &tv);
+	    }
+	    else
+#endif
+		if (size_count != NULL)
+	    {
+		++*size_count;
+		if (*first_size_win == NULL)
+		    *first_size_win = wp;
+		// For WinScrolled the first window with a size change is used
+		// even when it didn't scroll.
+		if (*first_scroll_win == NULL)
+		    *first_scroll_win = wp;
+	    }
+	}
+
+	int scroll_changed = wp->w_last_topline != wp->w_topline
+#ifdef FEAT_DIFF
+				|| wp->w_last_topfill != wp->w_topfill
+#endif
+				|| wp->w_last_leftcol != wp->w_leftcol
+				|| wp->w_last_skipcol != wp->w_skipcol;
+	if (scroll_changed)
+	{
+	    result |= CWSR_SCROLLED;
+	    if (first_scroll_win != NULL && *first_scroll_win == NULL)
+		*first_scroll_win = wp;
+	}
+
+#ifdef FEAT_EVAL
+	if ((size_changed || scroll_changed) && v_event != NULL)
+	{
+	    // Add info about this window to the v:event dictionary.
+	    int width = wp->w_width - wp->w_last_width;
+	    int height = wp->w_height - wp->w_last_height;
+	    int topline = wp->w_topline - wp->w_last_topline;
+#ifdef FEAT_DIFF
+	    int topfill = wp->w_topfill - wp->w_last_topfill;
+#endif
+	    int leftcol = wp->w_leftcol - wp->w_last_leftcol;
+	    int skipcol = wp->w_skipcol - wp->w_last_skipcol;
+	    dict_T *d = make_win_info_dict(width, height, topline,
+#ifdef FEAT_DIFF
+							    topfill,
+#endif
+							    leftcol, skipcol);
+	    if (d == NULL)
+		break;
+	    char winid[NUMBUFLEN];
+	    vim_snprintf(winid, sizeof(winid), "%d", wp->w_id);
+	    if (dict_add_dict(v_event, winid, d) == FAIL)
+	    {
+		dict_unref(d);
+		break;
+	    }
+	    --d->dv_refcount;
+
+	    tot_width += abs(width);
+	    tot_height += abs(height);
+	    tot_topline += abs(topline);
+#ifdef FEAT_DIFF
+	    tot_topfill += abs(topfill);
+#endif
+	    tot_leftcol += abs(leftcol);
+	    tot_skipcol += abs(skipcol);
+	}
+#endif
+    }
+
+#ifdef FEAT_EVAL
+    if (v_event != NULL)
+    {
+	dict_T *alldict = make_win_info_dict(tot_width, tot_height, tot_topline,
+# ifdef FEAT_DIFF
+						    tot_topfill,
+# endif
+						    tot_leftcol, tot_skipcol);
+	if (alldict != NULL)
+	{
+	    if (dict_add_dict(v_event, "all", alldict) == FAIL)
+		dict_unref(alldict);
+	    else
+		--alldict->dv_refcount;
+	}
+    }
+#endif
+
+    return result;
+}
+
+/*
+ * Trigger WinScrolled and/or WinResized if any window in the current tab page
+ * scrolled or changed size.
+ */
+    void
+may_trigger_win_scrolled_resized(void)
+{
+    static int	    recursive = FALSE;
+    int		    do_resize = has_winresized();
+    int		    do_scroll = has_winscrolled();
+
+    // Do not trigger WinScrolled or WinResized recursively.  Do not trigger
+    // before the initial snapshot of the w_last_ values was made.
+    if (recursive
+	    || !(do_scroll || do_resize)
+	    || !did_initial_scroll_size_snapshot)
+	return;
+
+    int size_count = 0;
+    win_T *first_scroll_win = NULL, *first_size_win = NULL;
+    int cwsr = check_window_scroll_resize(&size_count,
+					   &first_scroll_win, &first_size_win,
+					   NULL, NULL);
+    int trigger_resize = do_resize && size_count > 0;
+    int trigger_scroll = do_scroll && cwsr != 0;
+    if (!trigger_resize && !trigger_scroll)
+	return;  // no relevant changes
+#ifdef FEAT_EVAL
+    list_T *windows_list = NULL;
+    if (trigger_resize)
+    {
+	// Create the list for v:event.windows before making the snapshot.
+	windows_list = list_alloc_with_items(size_count);
+	(void)check_window_scroll_resize(NULL, NULL, NULL, windows_list, NULL);
+    }
+
+    dict_T *scroll_dict = NULL;
+    if (trigger_scroll)
+    {
+	// Create the dict with entries for v:event before making the snapshot.
+	scroll_dict = dict_alloc();
+	if (scroll_dict != NULL)
+	{
+	    scroll_dict->dv_refcount = 1;
+	    (void)check_window_scroll_resize(NULL, NULL, NULL, NULL,
+								  scroll_dict);
+	}
+    }
+#endif
+
+    // WinScrolled/WinResized are triggered only once, even when multiple
+    // windows scrolled or changed size.  Store the current values before
+    // triggering the event, if a scroll or resize happens as a side effect
+    // then WinScrolled/WinResized is triggered for that later.
+    snapshot_windows_scroll_size();
+
+    // "curwin" may be different from the actual current window, make
+    // sure it can be restored.
+    window_layout_lock();
+    recursive = TRUE;
+
+    // If both are to be triggered do WinResized first.
+    if (trigger_resize)
+    {
+#ifdef FEAT_EVAL
+	save_v_event_T  save_v_event;
+	dict_T		*v_event = get_v_event(&save_v_event);
+
+	if (dict_add_list(v_event, "windows", windows_list) == OK)
+	{
+	    dict_set_items_ro(v_event);
+#endif
+	    char_u winid[NUMBUFLEN];
+	    vim_snprintf((char *)winid, sizeof(winid), "%d",
+							 first_size_win->w_id);
+	    apply_autocmds(EVENT_WINRESIZED, winid, winid, FALSE,
+						     first_size_win->w_buffer);
+#ifdef FEAT_EVAL
+	}
+	restore_v_event(v_event, &save_v_event);
+#endif
+    }
+
+    if (trigger_scroll
+#ifdef FEAT_EVAL
+	    && scroll_dict != NULL
+#endif
+	    )
+    {
+#ifdef FEAT_EVAL
+	save_v_event_T  save_v_event;
+	dict_T		*v_event = get_v_event(&save_v_event);
+
+	// Move the entries from scroll_dict to v_event.
+	dict_extend(v_event, scroll_dict, (char_u *)"move", NULL);
+	dict_set_items_ro(v_event);
+	dict_unref(scroll_dict);
+#endif
+	char_u winid[NUMBUFLEN];
+	vim_snprintf((char *)winid, sizeof(winid), "%d",
+						       first_scroll_win->w_id);
+	apply_autocmds(EVENT_WINSCROLLED, winid, winid, FALSE,
+						   first_scroll_win->w_buffer);
+#ifdef FEAT_EVAL
+	restore_v_event(v_event, &save_v_event);
+#endif
+    }
+
+    recursive = FALSE;
+    window_layout_unlock();
+}
+
+/*
+ * Close window "win" in tab page "tp", which is not the current tab page.
+ * This may be the last window in that tab page and result in closing the tab,
+ * thus "tp" may become invalid!
+ * Caller must check if buffer is hidden and whether the tabline needs to be
+ * updated.
+ */
+    void
+win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
+{
+    win_T	*wp;
+    int		dir;
+    tabpage_T   *ptp = NULL;
+    int		free_tp = FALSE;
+
+    // Get here with win->w_buffer == NULL when win_close() detects the tab
+    // page changed.
+    if (win->w_closing || (win->w_buffer != NULL
+					       && win->w_buffer->b_locked > 0))
+	return; // window is already being closed
+
+    // Trigger WinClosed just before starting to free window-related resources.
+    trigger_winclosed(win);
+    // autocmd may have freed the window already.
+    if (!win_valid_any_tab(win))
+	return;
+
+    if (win->w_buffer != NULL)
+	// Close the link to the buffer.
+	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0,
+								 FALSE, TRUE);
+
+    // Careful: Autocommands may have closed the tab page or made it the
+    // current tab page.
+    for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
+	;
+    if (ptp == NULL || tp == curtab)
+    {
+	// If the buffer was removed from the window we have to give it any
+	// buffer.
+	if (win_valid_any_tab(win) && win->w_buffer == NULL)
+	{
+	    win->w_buffer = firstbuf;
+	    ++firstbuf->b_nwindows;
+	    win_init_empty(win);
+	}
+	return;
+    }
+
+    // Autocommands may have closed the window already.
+    for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
+	;
+    if (wp == NULL)
+	return;
+
+    // When closing the last window in a tab page remove the tab page.
+    if (tp->tp_firstwin == tp->tp_lastwin)
+    {
+	int	h = tabline_height();
+
+	if (tp == first_tabpage)
+	    first_tabpage = tp->tp_next;
+	else
+	{
+	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
+							   ptp = ptp->tp_next)
+		;
+	    if (ptp == NULL)
+	    {
+		internal_error("win_close_othertab()");
+		return;
+	    }
+	    ptp->tp_next = tp->tp_next;
+	}
+	free_tp = TRUE;
+	redraw_tabline = TRUE;
+	if (h != tabline_height())
+	    shell_new_rows();
+    }
+
+    // Free the memory used for the window.
+    win_free_mem(win, &dir, tp);
+
+    if (free_tp)
+	free_tabpage(tp);
+}
+
+/*
+ * Free the memory used for a window.
+ * Returns a pointer to the window that got the freed up space.
+ */
+    static win_T *
+win_free_mem(
+    win_T	*win,
+    int		*dirp,		// set to 'v' or 'h' for direction if 'ea'
+    tabpage_T	*tp)		// tab page "win" is in, NULL for current
+{
+    frame_T	*frp;
+    win_T	*wp;
+    tabpage_T	*win_tp = tp == NULL ? curtab : tp;
+
+    // Remove the window and its frame from the tree of frames.
+    frp = win->w_frame;
+    wp = winframe_remove(win, dirp, tp);
+    vim_free(frp);
+    win_free(win, tp);
+
+    // When deleting the current window in the tab, select a new current
+    // window.
+    if (win == win_tp->tp_curwin)
+	win_tp->tp_curwin = wp;
+
+    return wp;
+}
+
+#if defined(EXITFREE) || defined(PROTO)
+    void
+win_free_all(void)
+{
+    int		dummy;
+
+    // avoid an error for switching tabpage with the cmdline window open
+    cmdwin_type = 0;
+
+    while (first_tabpage->tp_next != NULL)
+	tabpage_close(TRUE);
+
+    for (int i = 0; i < AUCMD_WIN_COUNT; ++i)
+	if (aucmd_win[i].auc_win != NULL)
+	{
+	    (void)win_free_mem(aucmd_win[i].auc_win, &dummy, NULL);
+	    aucmd_win[i].auc_win = NULL;
+	}
+
+    while (firstwin != NULL)
+	(void)win_free_mem(firstwin, &dummy, NULL);
+
+    // No window should be used after this. Set curwin to NULL to crash
+    // instead of using freed memory.
+    curwin = NULL;
+}
+#endif
+
+/*
+ * Remove a window and its frame from the tree of frames.
+ * Returns a pointer to the window that got the freed up space.
+ */
+    win_T *
+winframe_remove(
+    win_T	*win,
+    int		*dirp UNUSED,	// set to 'v' or 'h' for direction if 'ea'
+    tabpage_T	*tp)		// tab page "win" is in, NULL for current
+{
+    frame_T	*frp, *frp2, *frp3;
+    frame_T	*frp_close = win->w_frame;
+    win_T	*wp;
+
+    /*
+     * If there is only one window there is nothing to remove.
+     */
+    if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
+	return NULL;
+
+    /*
+     * Remove the window from its frame.
+     */
+    frp2 = win_altframe(win, tp);
+    wp = frame2win(frp2);
+
+    // Remove this frame from the list of frames.
+    frame_remove(frp_close);
+
+    if (frp_close->fr_parent->fr_layout == FR_COL)
+    {
+	// When 'winfixheight' is set, try to find another frame in the column
+	// (as close to the closed frame as possible) to distribute the height
+	// to.
+	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
+	{
+	    frp = frp_close->fr_prev;
+	    frp3 = frp_close->fr_next;
+	    while (frp != NULL || frp3 != NULL)
+	    {
+		if (frp != NULL)
+		{
+		    if (!frame_fixed_height(frp))
+		    {
+			frp2 = frp;
+			wp = frame2win(frp2);
+			break;
+		    }
+		    frp = frp->fr_prev;
+		}
+		if (frp3 != NULL)
+		{
+		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
+		    {
+			frp2 = frp3;
+			wp = frp3->fr_win;
+			break;
+		    }
+		    frp3 = frp3->fr_next;
+		}
+	    }
+	}
+	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
+			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
+	*dirp = 'v';
+    }
+    else
+    {
+	// When 'winfixwidth' is set, try to find another frame in the column
+	// (as close to the closed frame as possible) to distribute the width
+	// to.
+	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
+	{
+	    frp = frp_close->fr_prev;
+	    frp3 = frp_close->fr_next;
+	    while (frp != NULL || frp3 != NULL)
+	    {
+		if (frp != NULL)
+		{
+		    if (!frame_fixed_width(frp))
+		    {
+			frp2 = frp;
+			wp = frame2win(frp2);
+			break;
+		    }
+		    frp = frp->fr_prev;
+		}
+		if (frp3 != NULL)
+		{
+		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
+		    {
+			frp2 = frp3;
+			wp = frp3->fr_win;
+			break;
+		    }
+		    frp3 = frp3->fr_next;
+		}
+	    }
+	}
+	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
+			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
+	*dirp = 'h';
+    }
+
+    // If rows/columns go to a window below/right its positions need to be
+    // updated.  Can only be done after the sizes have been updated.
+    if (frp2 == frp_close->fr_next)
+    {
+	int row = win->w_winrow;
+	int col = win->w_wincol;
+
+	frame_comp_pos(frp2, &row, &col);
+    }
+
+    if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
+    {
+	// There is no other frame in this list, move its info to the parent
+	// and remove it.
+	frp2->fr_parent->fr_layout = frp2->fr_layout;
+	frp2->fr_parent->fr_child = frp2->fr_child;
+	FOR_ALL_FRAMES(frp, frp2->fr_child)
+	    frp->fr_parent = frp2->fr_parent;
+	frp2->fr_parent->fr_win = frp2->fr_win;
+	if (frp2->fr_win != NULL)
+	    frp2->fr_win->w_frame = frp2->fr_parent;
+	frp = frp2->fr_parent;
+	if (topframe->fr_child == frp2)
+	    topframe->fr_child = frp;
+	vim_free(frp2);
+
+	frp2 = frp->fr_parent;
+	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
+	{
+	    // The frame above the parent has the same layout, have to merge
+	    // the frames into this list.
+	    if (frp2->fr_child == frp)
+		frp2->fr_child = frp->fr_child;
+	    frp->fr_child->fr_prev = frp->fr_prev;
+	    if (frp->fr_prev != NULL)
+		frp->fr_prev->fr_next = frp->fr_child;
+	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
+	    {
+		frp3->fr_parent = frp2;
+		if (frp3->fr_next == NULL)
+		{
+		    frp3->fr_next = frp->fr_next;
+		    if (frp->fr_next != NULL)
+			frp->fr_next->fr_prev = frp3;
+		    break;
+		}
+	    }
+	    if (topframe->fr_child == frp)
+		topframe->fr_child = frp2;
+	    vim_free(frp);
+	}
+    }
+
+    return wp;
+}
+
+/*
+ * Return a pointer to the frame that will receive the empty screen space that
+ * is left over after "win" is closed.
+ *
+ * If 'splitbelow' or 'splitright' is set, the space goes above or to the left
+ * by default.  Otherwise, the free space goes below or to the right.  The
+ * result is that opening a window and then immediately closing it will
+ * preserve the initial window layout.  The 'wfh' and 'wfw' settings are
+ * respected when possible.
+ */
+    static frame_T *
+win_altframe(
+    win_T	*win,
+    tabpage_T	*tp)		// tab page "win" is in, NULL for current
+{
+    frame_T	*frp;
+    frame_T	*other_fr, *target_fr;
+
+    if (tp == NULL ? ONE_WINDOW : tp->tp_firstwin == tp->tp_lastwin)
+	return alt_tabpage()->tp_curwin->w_frame;
+
+    frp = win->w_frame;
+
+    if (frp->fr_prev == NULL)
+	return frp->fr_next;
+    if (frp->fr_next == NULL)
+	return frp->fr_prev;
+
+    // By default the next window will get the space that was abandoned by this
+    // window
+    target_fr = frp->fr_next;
+    other_fr  = frp->fr_prev;
+
+    // If this is part of a column of windows and 'splitbelow' is true then the
+    // previous window will get the space.
+    if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_COL && p_sb)
+    {
+	target_fr = frp->fr_prev;
+	other_fr  = frp->fr_next;
+    }
+
+    // If this is part of a row of windows, and 'splitright' is true then the
+    // previous window will get the space.
+    if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW && p_spr)
+    {
+	target_fr = frp->fr_prev;
+	other_fr  = frp->fr_next;
+    }
+
+    // If 'wfh' or 'wfw' is set for the target and not for the alternate
+    // window, reverse the selection.
+    if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
+    {
+	if (frame_fixed_width(target_fr) && !frame_fixed_width(other_fr))
+	    target_fr = other_fr;
+    }
+    else
+    {
+	if (frame_fixed_height(target_fr) && !frame_fixed_height(other_fr))
+	    target_fr = other_fr;
+    }
+
+    return target_fr;
+}
+
+/*
+ * Return the tabpage that will be used if the current one is closed.
+ */
+    static tabpage_T *
+alt_tabpage(void)
+{
+    tabpage_T	*tp;
+
+    // Use the next tab page if possible.
+    if (curtab->tp_next != NULL)
+	return curtab->tp_next;
+
+    // Find the last but one tab page.
+    for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
+	;
+    return tp;
+}
+
+/*
+ * Find the left-upper window in frame "frp".
+ */
+    static win_T *
+frame2win(frame_T *frp)
+{
+    while (frp->fr_win == NULL)
+	frp = frp->fr_child;
+    return frp->fr_win;
+}
+
+/*
+ * Return TRUE if frame "frp" contains window "wp".
+ */
+    static int
+frame_has_win(frame_T *frp, win_T *wp)
+{
+    frame_T	*p;
+
+    if (frp->fr_layout == FR_LEAF)
+	return frp->fr_win == wp;
+
+    FOR_ALL_FRAMES(p, frp->fr_child)
+	if (frame_has_win(p, wp))
+	    return TRUE;
+    return FALSE;
+}
+
+/*
+ * Set a new height for a frame.  Recursively sets the height for contained
+ * frames and windows.  Caller must take care of positions.
+ */
+    static void
+frame_new_height(
+    frame_T	*topfrp,
+    int		height,
+    int		topfirst,	// resize topmost contained frame first
+    int		wfh)		// obey 'winfixheight' when there is a choice;
+				// may cause the height not to be set
+{
+    frame_T	*frp;
+    int		extra_lines;
+    int		h;
+
+    if (topfrp->fr_win != NULL)
+    {
+	// Simple case: just one window.
+	win_new_height(topfrp->fr_win,
+				    height - topfrp->fr_win->w_status_height
+					      - WINBAR_HEIGHT(topfrp->fr_win));
+    }
+    else if (topfrp->fr_layout == FR_ROW)
+    {
+	do
+	{
+	    // All frames in this row get the same new height.
+	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	    {
+		frame_new_height(frp, height, topfirst, wfh);
+		if (frp->fr_height > height)
+		{
+		    // Could not fit the windows, make the whole row higher.
+		    height = frp->fr_height;
+		    break;
+		}
+	    }
+	}
+	while (frp != NULL);
+    }
+    else    // fr_layout == FR_COL
+    {
+	// Complicated case: Resize a column of frames.  Resize the bottom
+	// frame first, frames above that when needed.
+
+	frp = topfrp->fr_child;
+	if (wfh)
+	    // Advance past frames with one window with 'wfh' set.
+	    while (frame_fixed_height(frp))
+	    {
+		frp = frp->fr_next;
+		if (frp == NULL)
+		    return;	    // no frame without 'wfh', give up
+	    }
+	if (!topfirst)
+	{
+	    // Find the bottom frame of this column
+	    while (frp->fr_next != NULL)
+		frp = frp->fr_next;
+	    if (wfh)
+		// Advance back for frames with one window with 'wfh' set.
+		while (frame_fixed_height(frp))
+		    frp = frp->fr_prev;
+	}
+
+	extra_lines = height - topfrp->fr_height;
+	if (extra_lines < 0)
+	{
+	    // reduce height of contained frames, bottom or top frame first
+	    while (frp != NULL)
+	    {
+		h = frame_minheight(frp, NULL);
+		if (frp->fr_height + extra_lines < h)
+		{
+		    extra_lines += frp->fr_height - h;
+		    frame_new_height(frp, h, topfirst, wfh);
+		}
+		else
+		{
+		    frame_new_height(frp, frp->fr_height + extra_lines,
+							       topfirst, wfh);
+		    break;
+		}
+		if (topfirst)
+		{
+		    do
+			frp = frp->fr_next;
+		    while (wfh && frp != NULL && frame_fixed_height(frp));
+		}
+		else
+		{
+		    do
+			frp = frp->fr_prev;
+		    while (wfh && frp != NULL && frame_fixed_height(frp));
+		}
+		// Increase "height" if we could not reduce enough frames.
+		if (frp == NULL)
+		    height -= extra_lines;
+	    }
+	}
+	else if (extra_lines > 0)
+	{
+	    // increase height of bottom or top frame
+	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
+	}
+    }
+    topfrp->fr_height = height;
+}
+
+/*
+ * Return TRUE if height of frame "frp" should not be changed because of
+ * the 'winfixheight' option.
+ */
+    static int
+frame_fixed_height(frame_T *frp)
+{
+    // frame with one window: fixed height if 'winfixheight' set.
+    if (frp->fr_win != NULL)
+	return frp->fr_win->w_p_wfh;
+
+    if (frp->fr_layout == FR_ROW)
+    {
+	// The frame is fixed height if one of the frames in the row is fixed
+	// height.
+	FOR_ALL_FRAMES(frp, frp->fr_child)
+	    if (frame_fixed_height(frp))
+		return TRUE;
+	return FALSE;
+    }
+
+    // frp->fr_layout == FR_COL: The frame is fixed height if all of the
+    // frames in the row are fixed height.
+    FOR_ALL_FRAMES(frp, frp->fr_child)
+	if (!frame_fixed_height(frp))
+	    return FALSE;
+    return TRUE;
+}
+
+/*
+ * Return TRUE if width of frame "frp" should not be changed because of
+ * the 'winfixwidth' option.
+ */
+    static int
+frame_fixed_width(frame_T *frp)
+{
+    // frame with one window: fixed width if 'winfixwidth' set.
+    if (frp->fr_win != NULL)
+	return frp->fr_win->w_p_wfw;
+
+    if (frp->fr_layout == FR_COL)
+    {
+	// The frame is fixed width if one of the frames in the row is fixed
+	// width.
+	FOR_ALL_FRAMES(frp, frp->fr_child)
+	    if (frame_fixed_width(frp))
+		return TRUE;
+	return FALSE;
+    }
+
+    // frp->fr_layout == FR_ROW: The frame is fixed width if all of the
+    // frames in the row are fixed width.
+    FOR_ALL_FRAMES(frp, frp->fr_child)
+	if (!frame_fixed_width(frp))
+	    return FALSE;
+    return TRUE;
+}
+
+/*
+ * Add a status line to windows at the bottom of "frp".
+ * Note: Does not check if there is room!
+ */
+    static void
+frame_add_statusline(frame_T *frp)
+{
+    win_T	*wp;
+
+    if (frp->fr_layout == FR_LEAF)
+    {
+	wp = frp->fr_win;
+	wp->w_status_height = STATUS_HEIGHT;
+    }
+    else if (frp->fr_layout == FR_ROW)
+    {
+	// Handle all the frames in the row.
+	FOR_ALL_FRAMES(frp, frp->fr_child)
+	    frame_add_statusline(frp);
+    }
+    else // frp->fr_layout == FR_COL
+    {
+	// Only need to handle the last frame in the column.
+	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
+	    ;
+	frame_add_statusline(frp);
+    }
+}
+
+/*
+ * Set width of a frame.  Handles recursively going through contained frames.
+ * May remove separator line for windows at the right side (for win_close()).
+ */
+    static void
+frame_new_width(
+    frame_T	*topfrp,
+    int		width,
+    int		leftfirst,	// resize leftmost contained frame first
+    int		wfw)		// obey 'winfixwidth' when there is a choice;
+				// may cause the width not to be set
+{
+    frame_T	*frp;
+    int		extra_cols;
+    int		w;
+    win_T	*wp;
+
+    if (topfrp->fr_layout == FR_LEAF)
+    {
+	// Simple case: just one window.
+	wp = topfrp->fr_win;
+	// Find out if there are any windows right of this one.
+	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
+	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
+		break;
+	if (frp->fr_parent == NULL)
+	    wp->w_vsep_width = 0;
+	win_new_width(wp, width - wp->w_vsep_width);
+    }
+    else if (topfrp->fr_layout == FR_COL)
+    {
+	do
+	{
+	    // All frames in this column get the same new width.
+	    FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	    {
+		frame_new_width(frp, width, leftfirst, wfw);
+		if (frp->fr_width > width)
+		{
+		    // Could not fit the windows, make whole column wider.
+		    width = frp->fr_width;
+		    break;
+		}
+	    }
+	} while (frp != NULL);
+    }
+    else    // fr_layout == FR_ROW
+    {
+	// Complicated case: Resize a row of frames.  Resize the rightmost
+	// frame first, frames left of it when needed.
+
+	frp = topfrp->fr_child;
+	if (wfw)
+	    // Advance past frames with one window with 'wfw' set.
+	    while (frame_fixed_width(frp))
+	    {
+		frp = frp->fr_next;
+		if (frp == NULL)
+		    return;	    // no frame without 'wfw', give up
+	    }
+	if (!leftfirst)
+	{
+	    // Find the rightmost frame of this row
+	    while (frp->fr_next != NULL)
+		frp = frp->fr_next;
+	    if (wfw)
+		// Advance back for frames with one window with 'wfw' set.
+		while (frame_fixed_width(frp))
+		    frp = frp->fr_prev;
+	}
+
+	extra_cols = width - topfrp->fr_width;
+	if (extra_cols < 0)
+	{
+	    // reduce frame width, rightmost frame first
+	    while (frp != NULL)
+	    {
+		w = frame_minwidth(frp, NULL);
+		if (frp->fr_width + extra_cols < w)
+		{
+		    extra_cols += frp->fr_width - w;
+		    frame_new_width(frp, w, leftfirst, wfw);
+		}
+		else
+		{
+		    frame_new_width(frp, frp->fr_width + extra_cols,
+							      leftfirst, wfw);
+		    break;
+		}
+		if (leftfirst)
+		{
+		    do
+			frp = frp->fr_next;
+		    while (wfw && frp != NULL && frame_fixed_width(frp));
+		}
+		else
+		{
+		    do
+			frp = frp->fr_prev;
+		    while (wfw && frp != NULL && frame_fixed_width(frp));
+		}
+		// Increase "width" if we could not reduce enough frames.
+		if (frp == NULL)
+		    width -= extra_cols;
+	    }
+	}
+	else if (extra_cols > 0)
+	{
+	    // increase width of rightmost frame
+	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
+	}
+    }
+    topfrp->fr_width = width;
+}
+
+/*
+ * Add the vertical separator to windows at the right side of "frp".
+ * Note: Does not check if there is room!
+ */
+    static void
+frame_add_vsep(frame_T *frp)
+{
+    win_T	*wp;
+
+    if (frp->fr_layout == FR_LEAF)
+    {
+	wp = frp->fr_win;
+	if (wp->w_vsep_width == 0)
+	{
+	    if (wp->w_width > 0)	// don't make it negative
+		--wp->w_width;
+	    wp->w_vsep_width = 1;
+	}
+    }
+    else if (frp->fr_layout == FR_COL)
+    {
+	// Handle all the frames in the column.
+	FOR_ALL_FRAMES(frp, frp->fr_child)
+	    frame_add_vsep(frp);
+    }
+    else // frp->fr_layout == FR_ROW
+    {
+	// Only need to handle the last frame in the row.
+	frp = frp->fr_child;
+	while (frp->fr_next != NULL)
+	    frp = frp->fr_next;
+	frame_add_vsep(frp);
+    }
+}
+
+/*
+ * Set frame width from the window it contains.
+ */
+    static void
+frame_fix_width(win_T *wp)
+{
+    wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
+}
+
+/*
+ * Set frame height from the window it contains.
+ */
+    static void
+frame_fix_height(win_T *wp)
+{
+    wp->w_frame->fr_height = VISIBLE_HEIGHT(wp) + wp->w_status_height;
+}
+
+/*
+ * Compute the minimal height for frame "topfrp".
+ * Uses the 'winminheight' option.
+ * When "next_curwin" isn't NULL, use p_wh for this window.
+ * When "next_curwin" is NOWIN, don't use at least one line for the current
+ * window.
+ */
+    static int
+frame_minheight(frame_T *topfrp, win_T *next_curwin)
+{
+    frame_T	*frp;
+    int		m;
+    int		n;
+
+    if (topfrp->fr_win != NULL)
+    {
+	if (topfrp->fr_win == next_curwin)
+	    m = p_wh + topfrp->fr_win->w_status_height;
+	else
+	{
+	    // window: minimal height of the window plus status line
+	    m = p_wmh + topfrp->fr_win->w_status_height;
+	    if (topfrp->fr_win == curwin && next_curwin == NULL)
+	    {
+		// Current window is minimal one line high and WinBar is
+		// visible.
+		if (p_wmh == 0)
+		    ++m;
+		m += WINBAR_HEIGHT(curwin);
+	    }
+	}
+    }
+    else if (topfrp->fr_layout == FR_ROW)
+    {
+	// get the minimal height from each frame in this row
+	m = 0;
+	FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	{
+	    n = frame_minheight(frp, next_curwin);
+	    if (n > m)
+		m = n;
+	}
+    }
+    else
+    {
+	// Add up the minimal heights for all frames in this column.
+	m = 0;
+	FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	    m += frame_minheight(frp, next_curwin);
+    }
+
+    return m;
+}
+
+/*
+ * Compute the minimal width for frame "topfrp".
+ * When "next_curwin" isn't NULL, use p_wiw for this window.
+ * When "next_curwin" is NOWIN, don't use at least one column for the current
+ * window.
+ */
+    static int
+frame_minwidth(
+    frame_T	*topfrp,
+    win_T	*next_curwin)	// use p_wh and p_wiw for next_curwin
+{
+    frame_T	*frp;
+    int		m, n;
+
+    if (topfrp->fr_win != NULL)
+    {
+	if (topfrp->fr_win == next_curwin)
+	    m = p_wiw + topfrp->fr_win->w_vsep_width;
+	else
+	{
+	    // window: minimal width of the window plus separator column
+	    m = p_wmw + topfrp->fr_win->w_vsep_width;
+	    // Current window is minimal one column wide
+	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
+		++m;
+	}
+    }
+    else if (topfrp->fr_layout == FR_COL)
+    {
+	// get the minimal width from each frame in this column
+	m = 0;
+	FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	{
+	    n = frame_minwidth(frp, next_curwin);
+	    if (n > m)
+		m = n;
+	}
+    }
+    else
+    {
+	// Add up the minimal widths for all frames in this row.
+	m = 0;
+	FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	    m += frame_minwidth(frp, next_curwin);
+    }
+
+    return m;
+}
+
+
+/*
+ * Try to close all windows except current one.
+ * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
+ * used and the buffer was modified.
+ *
+ * Used by ":bdel" and ":only".
+ */
+    void
+close_others(
+    int		message,
+    int		forceit)	    // always hide all other windows
+{
+    win_T	*wp;
+    win_T	*nextwp;
+    int		r;
+
+    if (one_window())
+    {
+	if (message && !autocmd_busy)
+	    msg(_(m_onlyone));
+	return;
+    }
+
+    // Be very careful here: autocommands may change the window layout.
+    for (wp = firstwin; win_valid(wp); wp = nextwp)
+    {
+	nextwp = wp->w_next;
+	if (wp == curwin)		// don't close current window
+	    continue;
+
+	// autoccommands messed this one up
+	if (!buf_valid(wp->w_buffer) && win_valid(wp))
+	{
+	    wp->w_buffer = NULL;
+	    win_close(wp, 0);
+	    continue;
+	}
+	// Check if it's allowed to abandon this window
+	r = can_abandon(wp->w_buffer, forceit);
+	if (!win_valid(wp))		// autocommands messed wp up
+	{
+	    nextwp = firstwin;
+	    continue;
+	}
+	if (!r)
+	{
+#if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
+	    if (message && (p_confirm
+			 || (cmdmod.cmod_flags & CMOD_CONFIRM)) && p_write)
+	    {
+		dialog_changed(wp->w_buffer, FALSE);
+		if (!win_valid(wp))		// autocommands messed wp up
+		{
+		    nextwp = firstwin;
+		    continue;
+		}
+	    }
+	    if (bufIsChanged(wp->w_buffer))
+#endif
+		continue;
+	}
+	win_close(wp, !buf_hide(wp->w_buffer) && !bufIsChanged(wp->w_buffer));
+    }
+
+    if (message && !ONE_WINDOW)
+	emsg(_(e_other_window_contains_changes));
+}
+
+/*
+ * Store the relevant window pointers for tab page "tp".  To be used before
+ * use_tabpage().
+ */
+    void
+unuse_tabpage(tabpage_T *tp)
+{
+    tp->tp_topframe = topframe;
+    tp->tp_firstwin = firstwin;
+    tp->tp_lastwin = lastwin;
+    tp->tp_curwin = curwin;
+}
+
+/*
+ * Set the relevant pointers to use tab page "tp".  May want to call
+ * unuse_tabpage() first.
+ */
+    void
+use_tabpage(tabpage_T *tp)
+{
+    curtab = tp;
+    topframe = curtab->tp_topframe;
+    firstwin = curtab->tp_firstwin;
+    lastwin = curtab->tp_lastwin;
+    curwin = curtab->tp_curwin;
+}
+
+/*
+ * Allocate the first window and put an empty buffer in it.
+ * Called from main().
+ * Return FAIL when something goes wrong (out of memory).
+ */
+    int
+win_alloc_first(void)
+{
+    if (win_alloc_firstwin(NULL) == FAIL)
+	return FAIL;
+
+    first_tabpage = alloc_tabpage();
+    if (first_tabpage == NULL)
+	return FAIL;
+    curtab = first_tabpage;
+    unuse_tabpage(first_tabpage);
+
+    return OK;
+}
+
+/*
+ * Allocate and init a window that is not a regular window.
+ * This can only be done after the first window is fully initialized, thus it
+ * can't be in win_alloc_first().
+ */
+    win_T *
+win_alloc_popup_win(void)
+{
+    win_T *wp;
+
+    wp = win_alloc(NULL, TRUE);
+    if (wp == NULL)
+	return NULL;
+    // We need to initialize options with something, using the current
+    // window makes most sense.
+    win_init_some(wp, curwin);
+
+    RESET_BINDING(wp);
+    new_frame(wp);
+    return wp;
+}
+
+/*
+ * Initialize window "wp" to display buffer "buf".
+ */
+    void
+win_init_popup_win(win_T *wp, buf_T *buf)
+{
+    wp->w_buffer = buf;
+    ++buf->b_nwindows;
+    win_init_empty(wp); // set cursor and topline to safe values
+
+    // Make sure w_localdir and globaldir are NULL to avoid a chdir() in
+    // win_enter_ext().
+    VIM_CLEAR(wp->w_localdir);
+}
+
+/*
+ * Allocate the first window or the first window in a new tab page.
+ * When "oldwin" is NULL create an empty buffer for it.
+ * When "oldwin" is not NULL copy info from it to the new window.
+ * Return FAIL when something goes wrong (out of memory).
+ */
+    static int
+win_alloc_firstwin(win_T *oldwin)
+{
+    curwin = win_alloc(NULL, FALSE);
+    if (curwin == NULL)
+	return FAIL;
+    if (oldwin == NULL)
+    {
+	// Very first window, need to create an empty buffer for it and
+	// initialize from scratch.
+	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
+	if (curwin == NULL || curbuf == NULL)
+	    return FAIL;
+	curwin->w_buffer = curbuf;
+#ifdef FEAT_SYN_HL
+	curwin->w_s = &(curbuf->b_s);
+#endif
+	curbuf->b_nwindows = 1;	// there is one window
+	curwin->w_alist = &global_alist;
+	curwin_init();		// init current window
+    }
+    else
+    {
+	// First window in new tab page, initialize it from "oldwin".
+	win_init(curwin, oldwin, 0);
+
+	// We don't want cursor- and scroll-binding in the first window.
+	RESET_BINDING(curwin);
+    }
+
+    new_frame(curwin);
+    if (curwin->w_frame == NULL)
+	return FAIL;
+    topframe = curwin->w_frame;
+    topframe->fr_width = Columns;
+    topframe->fr_height = Rows - p_ch;
+
+    return OK;
+}
+
+/*
+ * Create a frame for window "wp".
+ */
+    static void
+new_frame(win_T *wp)
+{
+    frame_T *frp = ALLOC_CLEAR_ONE(frame_T);
+
+    wp->w_frame = frp;
+    if (frp == NULL)
+	return;
+    frp->fr_layout = FR_LEAF;
+    frp->fr_win = wp;
+}
+
+/*
+ * Initialize the window and frame size to the maximum.
+ */
+    void
+win_init_size(void)
+{
+    firstwin->w_height = ROWS_AVAIL;
+    firstwin->w_prev_height = ROWS_AVAIL;
+    topframe->fr_height = ROWS_AVAIL;
+    firstwin->w_width = Columns;
+    topframe->fr_width = Columns;
+}
+
+/*
+ * Allocate a new tabpage_T and init the values.
+ * Returns NULL when out of memory.
+ */
+    static tabpage_T *
+alloc_tabpage(void)
+{
+    tabpage_T	*tp;
+# ifdef FEAT_GUI
+    int		i;
+# endif
+
+
+    tp = ALLOC_CLEAR_ONE(tabpage_T);
+    if (tp == NULL)
+	return NULL;
+
+# ifdef FEAT_EVAL
+    // init t: variables
+    tp->tp_vars = dict_alloc_id(aid_newtabpage_tvars);
+    if (tp->tp_vars == NULL)
+    {
+	vim_free(tp);
+	return NULL;
+    }
+    init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
+# endif
+
+# ifdef FEAT_GUI
+    for (i = 0; i < 3; i++)
+	tp->tp_prev_which_scrollbars[i] = -1;
+# endif
+# ifdef FEAT_DIFF
+    tp->tp_diff_invalid = TRUE;
+# endif
+    tp->tp_ch_used = p_ch;
+
+    return tp;
+}
+
+    void
+free_tabpage(tabpage_T *tp)
+{
+    int idx;
+
+# ifdef FEAT_DIFF
+    diff_clear(tp);
+# endif
+# ifdef FEAT_PROP_POPUP
+    while (tp->tp_first_popupwin != NULL)
+	popup_close_tabpage(tp, tp->tp_first_popupwin->w_id, TRUE);
+#endif
+    for (idx = 0; idx < SNAP_COUNT; ++idx)
+	clear_snapshot(tp, idx);
+#ifdef FEAT_EVAL
+    vars_clear(&tp->tp_vars->dv_hashtab);	// free all t: variables
+    hash_init(&tp->tp_vars->dv_hashtab);
+    unref_var_dict(tp->tp_vars);
+#endif
+
+    if (tp == lastused_tabpage)
+	lastused_tabpage = NULL;
+
+    vim_free(tp->tp_localdir);
+    vim_free(tp->tp_prevdir);
+
+#ifdef FEAT_PYTHON
+    python_tabpage_free(tp);
+#endif
+
+#ifdef FEAT_PYTHON3
+    python3_tabpage_free(tp);
+#endif
+
+    vim_free(tp);
+}
+
+/*
+ * Create a new Tab page with one window.
+ * It will edit the current buffer, like after ":split".
+ * When "after" is 0 put it just after the current Tab page.
+ * Otherwise put it just before tab page "after".
+ * Return FAIL or OK.
+ */
+    int
+win_new_tabpage(int after)
+{
+    tabpage_T	*tp = curtab;
+    tabpage_T	*prev_tp = curtab;
+    tabpage_T	*newtp;
+    int		n;
+
+    if (cmdwin_type != 0)
+    {
+	emsg(_(e_invalid_in_cmdline_window));
+	return FAIL;
+    }
+    if (window_layout_locked(CMD_tabnew))
+	return FAIL;
+
+    newtp = alloc_tabpage();
+    if (newtp == NULL)
+	return FAIL;
+
+    // Remember the current windows in this Tab page.
+    if (leave_tabpage(curbuf, TRUE) == FAIL)
+    {
+	vim_free(newtp);
+	return FAIL;
+    }
+    curtab = newtp;
+
+    newtp->tp_localdir = (tp->tp_localdir == NULL)
+				    ? NULL : vim_strsave(tp->tp_localdir);
+    // Create a new empty window.
+    if (win_alloc_firstwin(tp->tp_curwin) == OK)
+    {
+	// Make the new Tab page the new topframe.
+	if (after == 1)
+	{
+	    // New tab page becomes the first one.
+	    newtp->tp_next = first_tabpage;
+	    first_tabpage = newtp;
+	}
+	else
+	{
+	    if (after > 0)
+	    {
+		// Put new tab page before tab page "after".
+		n = 2;
+		for (tp = first_tabpage; tp->tp_next != NULL
+					       && n < after; tp = tp->tp_next)
+		    ++n;
+	    }
+	    newtp->tp_next = tp->tp_next;
+	    tp->tp_next = newtp;
+	}
+	newtp->tp_firstwin = newtp->tp_lastwin = newtp->tp_curwin = curwin;
+
+	win_init_size();
+	firstwin->w_winrow = tabline_height();
+	firstwin->w_prev_winrow = firstwin->w_winrow;
+	win_comp_scroll(curwin);
+
+	newtp->tp_topframe = topframe;
+	last_status(FALSE);
+
+	lastused_tabpage = prev_tp;
+
+#if defined(FEAT_GUI)
+	// When 'guioptions' includes 'L' or 'R' may have to remove or add
+	// scrollbars.  Have to update them anyway.
+	gui_may_update_scrollbars();
+#endif
+#ifdef FEAT_JOB_CHANNEL
+	entering_window(curwin);
+#endif
+
+	redraw_all_later(UPD_NOT_VALID);
+	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
+	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
+	apply_autocmds(EVENT_TABNEW, NULL, NULL, FALSE, curbuf);
+	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
+	return OK;
+    }
+
+    // Failed, get back the previous Tab page
+    enter_tabpage(curtab, curbuf, TRUE, TRUE);
+    return FAIL;
+}
+
+/*
+ * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
+ * like with ":split".
+ * Returns OK if a new tab page was created, FAIL otherwise.
+ */
+    static int
+may_open_tabpage(void)
+{
+    int		n = (cmdmod.cmod_tab == 0)
+				       ? postponed_split_tab : cmdmod.cmod_tab;
+
+    if (n == 0)
+	return FAIL;
+
+    cmdmod.cmod_tab = 0;	    // reset it to avoid doing it twice
+    postponed_split_tab = 0;
+    return win_new_tabpage(n);
+}
+
+/*
+ * Create up to "maxcount" tabpages with empty windows.
+ * Returns the number of resulting tab pages.
+ */
+    int
+make_tabpages(int maxcount)
+{
+    int		count = maxcount;
+    int		todo;
+
+    // Limit to 'tabpagemax' tabs.
+    if (count > p_tpm)
+	count = p_tpm;
+
+    /*
+     * Don't execute autocommands while creating the tab pages.  Must do that
+     * when putting the buffers in the windows.
+     */
+    block_autocmds();
+
+    for (todo = count - 1; todo > 0; --todo)
+	if (win_new_tabpage(0) == FAIL)
+	    break;
+
+    unblock_autocmds();
+
+    // return actual number of tab pages
+    return (count - todo);
+}
+
+/*
+ * Return TRUE when "tpc" points to a valid tab page.
+ */
+    int
+valid_tabpage(tabpage_T *tpc)
+{
+    tabpage_T	*tp;
+
+    FOR_ALL_TABPAGES(tp)
+	if (tp == tpc)
+	    return TRUE;
+    return FALSE;
+}
+
+/*
+ * Return TRUE when "tpc" points to a valid tab page and at least one window is
+ * valid.
+ */
+    int
+valid_tabpage_win(tabpage_T *tpc)
+{
+    tabpage_T	*tp;
+    win_T	*wp;
+
+    FOR_ALL_TABPAGES(tp)
+    {
+	if (tp == tpc)
+	{
+	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
+	    {
+		if (win_valid_any_tab(wp))
+		    return TRUE;
+	    }
+	    return FALSE;
+	}
+    }
+    // shouldn't happen
+    return FALSE;
+}
+
+/*
+ * Close tabpage "tab", assuming it has no windows in it.
+ * There must be another tabpage or this will crash.
+ */
+    void
+close_tabpage(tabpage_T *tab)
+{
+    tabpage_T	*ptp;
+
+    if (tab == first_tabpage)
+    {
+	first_tabpage = tab->tp_next;
+	ptp = first_tabpage;
+    }
+    else
+    {
+	for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tab;
+							    ptp = ptp->tp_next)
+	    ;
+	assert(ptp != NULL);
+	ptp->tp_next = tab->tp_next;
+    }
+
+    goto_tabpage_tp(ptp, FALSE, FALSE);
+    free_tabpage(tab);
+}
+
+/*
+ * Find tab page "n" (first one is 1).  Returns NULL when not found.
+ */
+    tabpage_T *
+find_tabpage(int n)
+{
+    tabpage_T	*tp;
+    int		i = 1;
+
+    if (n == 0)
+	return curtab;
+
+    for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
+	++i;
+    return tp;
+}
+
+/*
+ * Get index of tab page "tp".  First one has index 1.
+ * When not found returns number of tab pages plus one.
+ */
+    int
+tabpage_index(tabpage_T *ftp)
+{
+    int		i = 1;
+    tabpage_T	*tp;
+
+    for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
+	++i;
+    return i;
+}
+
+/*
+ * Prepare for leaving the current tab page.
+ * When autocommands change "curtab" we don't leave the tab page and return
+ * FAIL.
+ * Careful: When OK is returned need to get a new tab page very very soon!
+ */
+    static int
+leave_tabpage(
+    buf_T	*new_curbuf UNUSED,    // what is going to be the new curbuf,
+				       // NULL if unknown
+    int		trigger_leave_autocmds)
+{
+    tabpage_T	*tp = curtab;
+
+#ifdef FEAT_JOB_CHANNEL
+    leaving_window(curwin);
+#endif
+    reset_VIsual_and_resel();	// stop Visual mode
+    if (trigger_leave_autocmds)
+    {
+	if (new_curbuf != curbuf)
+	{
+	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
+	    if (curtab != tp)
+		return FAIL;
+	}
+	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
+	if (curtab != tp)
+	    return FAIL;
+	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
+	if (curtab != tp)
+	    return FAIL;
+    }
+
+    reset_dragwin();
+#if defined(FEAT_GUI)
+    // Remove the scrollbars.  They may be added back later.
+    if (gui.in_use)
+	gui_remove_scrollbars();
+#endif
+    tp->tp_curwin = curwin;
+    tp->tp_prevwin = prevwin;
+    tp->tp_firstwin = firstwin;
+    tp->tp_lastwin = lastwin;
+    tp->tp_old_Rows = Rows;
+    if (tp->tp_old_Columns != -1)
+	tp->tp_old_Columns = Columns;
+    firstwin = NULL;
+    lastwin = NULL;
+    return OK;
+}
+
+/*
+ * Start using tab page "tp".
+ * Only to be used after leave_tabpage() or freeing the current tab page.
+ * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
+ * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
+ */
+    static void
+enter_tabpage(
+    tabpage_T	*tp,
+    buf_T	*old_curbuf UNUSED,
+    int		trigger_enter_autocmds,
+    int		trigger_leave_autocmds)
+{
+    int		row;
+    int		old_off = tp->tp_firstwin->w_winrow;
+    win_T	*next_prevwin = tp->tp_prevwin;
+    tabpage_T	*last_tab = curtab;
+
+    use_tabpage(tp);
+
+    // We would like doing the TabEnter event first, but we don't have a
+    // valid current window yet, which may break some commands.
+    // This triggers autocommands, thus may make "tp" invalid.
+    (void)win_enter_ext(tp->tp_curwin, WEE_CURWIN_INVALID
+		  | (trigger_enter_autocmds ? WEE_TRIGGER_ENTER_AUTOCMDS : 0)
+		  | (trigger_leave_autocmds ? WEE_TRIGGER_LEAVE_AUTOCMDS : 0));
+    prevwin = next_prevwin;
+
+    last_status(FALSE);		// status line may appear or disappear
+    row = win_comp_pos();	// recompute w_winrow for all windows
+#ifdef FEAT_DIFF
+    diff_need_scrollbind = TRUE;
+#endif
+
+    // Use the stored value of p_ch, so that it can be different for each tab
+    // page.
+    if (p_ch != curtab->tp_ch_used)
+	clear_cmdline = TRUE;
+    p_ch = curtab->tp_ch_used;
+
+    // When cmdheight is changed in a tab page with '<C-w>-', cmdline_row is
+    // changed but p_ch and tp_ch_used are not changed. Thus we also need to
+    // check cmdline_row.
+    if (row < cmdline_row && cmdline_row <= Rows - p_ch)
+	clear_cmdline = TRUE;
+
+    // If there was a click in a window, it won't be usable for a following
+    // drag.
+    reset_dragwin();
+
+    // The tabpage line may have appeared or disappeared, may need to resize
+    // the frames for that.  When the Vim window was resized need to update
+    // frame sizes too.
+    if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
+#ifdef FEAT_GUI_TABLINE
+			    && !gui_use_tabline()
+#endif
+		))
+	shell_new_rows();
+    if (curtab->tp_old_Columns != Columns)
+    {
+	if (starting == 0)
+	{
+	    shell_new_columns();	// update window widths
+	    curtab->tp_old_Columns = Columns;
+	}
+	else
+	    curtab->tp_old_Columns = -1;  // update window widths later
+    }
+
+    lastused_tabpage = last_tab;
+
+#if defined(FEAT_GUI)
+    // When 'guioptions' includes 'L' or 'R' may have to remove or add
+    // scrollbars.  Have to update them anyway.
+    gui_may_update_scrollbars();
+#endif
+
+    // Apply autocommands after updating the display, when 'rows' and
+    // 'columns' have been set correctly.
+    if (trigger_enter_autocmds)
+    {
+	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
+	if (old_curbuf != curbuf)
+	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
+    }
+
+    redraw_all_later(UPD_NOT_VALID);
+}
+
+/*
+ * Go to tab page "n".  For ":tab N" and "Ngt".
+ * When "n" is 9999 go to the last tab page.
+ */
+    void
+goto_tabpage(int n)
+{
+    tabpage_T	*tp = NULL;  // shut up compiler
+    tabpage_T	*ttp;
+    int		i;
+
+    if (text_locked())
+    {
+	// Not allowed when editing the command line.
+	text_locked_msg();
+	return;
+    }
+
+    // If there is only one it can't work.
+    if (first_tabpage->tp_next == NULL)
+    {
+	if (n > 1)
+	    beep_flush();
+	return;
+    }
+
+    if (n == 0)
+    {
+	// No count, go to next tab page, wrap around end.
+	if (curtab->tp_next == NULL)
+	    tp = first_tabpage;
+	else
+	    tp = curtab->tp_next;
+    }
+    else if (n < 0)
+    {
+	// "gT": go to previous tab page, wrap around end.  "N gT" repeats
+	// this N times.
+	ttp = curtab;
+	for (i = n; i < 0; ++i)
+	{
+	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
+		    tp = tp->tp_next)
+		;
+	    ttp = tp;
+	}
+    }
+    else if (n == 9999)
+    {
+	// Go to last tab page.
+	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
+	    ;
+    }
+    else
+    {
+	// Go to tab page "n".
+	tp = find_tabpage(n);
+	if (tp == NULL)
+	{
+	    beep_flush();
+	    return;
+	}
+    }
+
+    goto_tabpage_tp(tp, TRUE, TRUE);
+
+#ifdef FEAT_GUI_TABLINE
+    if (gui_use_tabline())
+	gui_mch_set_curtab(tabpage_index(curtab));
+#endif
+}
+
+/*
+ * Go to tabpage "tp".
+ * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
+ * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
+ * Note: doesn't update the GUI tab.
+ */
+    void
+goto_tabpage_tp(
+    tabpage_T	*tp,
+    int		trigger_enter_autocmds,
+    int		trigger_leave_autocmds)
+{
+    if (trigger_enter_autocmds || trigger_leave_autocmds)
+	CHECK_CMDWIN;
+
+    // Don't repeat a message in another tab page.
+    set_keep_msg(NULL, 0);
+
+    skip_win_fix_scroll = TRUE;
+    if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
+					trigger_leave_autocmds) == OK)
+    {
+	if (valid_tabpage(tp))
+	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
+		    trigger_leave_autocmds);
+	else
+	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
+		    trigger_leave_autocmds);
+    }
+    skip_win_fix_scroll = FALSE;
+}
+
+/*
+ * Go to the last accessed tab page, if there is one.
+ * Return OK or FAIL
+ */
+    int
+goto_tabpage_lastused(void)
+{
+    if (!valid_tabpage(lastused_tabpage))
+	return FAIL;
+
+    goto_tabpage_tp(lastused_tabpage, TRUE, TRUE);
+    return OK;
+}
+
+/*
+ * Enter window "wp" in tab page "tp".
+ * Also updates the GUI tab.
+ */
+    void
+goto_tabpage_win(tabpage_T *tp, win_T *wp)
+{
+    goto_tabpage_tp(tp, TRUE, TRUE);
+    if (curtab == tp && win_valid(wp))
+    {
+	win_enter(wp, TRUE);
+# ifdef FEAT_GUI_TABLINE
+	if (gui_use_tabline())
+	    gui_mch_set_curtab(tabpage_index(curtab));
+# endif
+    }
+}
+
+/*
+ * Move the current tab page to after tab page "nr".
+ */
+    void
+tabpage_move(int nr)
+{
+    int		n = 1;
+    tabpage_T	*tp, *tp_dst;
+
+    if (first_tabpage->tp_next == NULL)
+	return;
+
+    if (tabpage_move_disallowed)
+	return;
+
+    for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
+	++n;
+
+    if (tp == curtab || (nr > 0 && tp->tp_next != NULL
+						    && tp->tp_next == curtab))
+	return;
+
+    tp_dst = tp;
+
+    // Remove the current tab page from the list of tab pages.
+    if (curtab == first_tabpage)
+	first_tabpage = curtab->tp_next;
+    else
+    {
+	FOR_ALL_TABPAGES(tp)
+	    if (tp->tp_next == curtab)
+		break;
+	if (tp == NULL)	// "cannot happen"
+	    return;
+	tp->tp_next = curtab->tp_next;
+    }
+
+    // Re-insert it at the specified position.
+    if (nr <= 0)
+    {
+	curtab->tp_next = first_tabpage;
+	first_tabpage = curtab;
+    }
+    else
+    {
+	curtab->tp_next = tp_dst->tp_next;
+	tp_dst->tp_next = curtab;
+    }
+
+    // Need to redraw the tabline.  Tab page contents doesn't change.
+    redraw_tabline = TRUE;
+}
+
+
+/*
+ * Go to another window.
+ * When jumping to another buffer, stop Visual mode.  Do this before
+ * changing windows so we can yank the selection into the '*' register.
+ * (note: this may trigger ModeChanged autocommand!)
+ * When jumping to another window on the same buffer, adjust its cursor
+ * position to keep the same Visual area.
+ */
+    void
+win_goto(win_T *wp)
+{
+#ifdef FEAT_CONCEAL
+    win_T	*owp = curwin;
+#endif
+
+#ifdef FEAT_PROP_POPUP
+    if (ERROR_IF_ANY_POPUP_WINDOW)
+	return;
+    if (popup_is_popup(wp))
+    {
+	emsg(_(e_not_allowed_to_enter_popup_window));
+	return;
+    }
+#endif
+    if (text_or_buf_locked())
+    {
+	beep_flush();
+	return;
+    }
+
+    if (wp->w_buffer != curbuf)
+	// careful: triggers ModeChanged autocommand
+	reset_VIsual_and_resel();
+    else if (VIsual_active)
+	wp->w_cursor = curwin->w_cursor;
+
+    // autocommand may have made wp invalid
+    if (!win_valid(wp))
+	return;
+
+#ifdef FEAT_GUI
+    need_mouse_correct = TRUE;
+#endif
+    win_enter(wp, TRUE);
+
+#ifdef FEAT_CONCEAL
+    // Conceal cursor line in previous window, unconceal in current window.
+    if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
+	redrawWinline(owp, owp->w_cursor.lnum);
+    if (curwin->w_p_cole > 0 && !msg_scrolled)
+	need_cursor_line_redraw = TRUE;
+#endif
+}
+
+#if defined(FEAT_PERL) || defined(PROTO)
+/*
+ * Find window number "winnr" (counting top to bottom).
+ */
+    win_T *
+win_find_nr(int winnr)
+{
+    win_T	*wp;
+
+    FOR_ALL_WINDOWS(wp)
+	if (--winnr == 0)
+	    break;
+    return wp;
+}
+#endif
+
+#if ((defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) || defined(PROTO)
+/*
+ * Find the tabpage for window "win".
+ */
+    tabpage_T *
+win_find_tabpage(win_T *win)
+{
+    win_T	*wp;
+    tabpage_T	*tp;
+
+    FOR_ALL_TAB_WINDOWS(tp, wp)
+	    if (wp == win)
+		return tp;
+    return NULL;
+}
+#endif
+
+/*
+ * Get the above or below neighbor window of the specified window.
+ *   up - TRUE for the above neighbor
+ *   count - nth neighbor window
+ * Returns the specified window if the neighbor is not found.
+ */
+    win_T *
+win_vert_neighbor(tabpage_T *tp, win_T *wp, int up, long count)
+{
+    frame_T	*fr;
+    frame_T	*nfr;
+    frame_T	*foundfr;
+
+#ifdef FEAT_PROP_POPUP
+    if (popup_is_popup(wp))
+	// popups don't have neighbors.
+	return NULL;
+#endif
+    foundfr = wp->w_frame;
+    while (count--)
+    {
+	/*
+	 * First go upwards in the tree of frames until we find a upwards or
+	 * downwards neighbor.
+	 */
+	fr = foundfr;
+	for (;;)
+	{
+	    if (fr == tp->tp_topframe)
+		goto end;
+	    if (up)
+		nfr = fr->fr_prev;
+	    else
+		nfr = fr->fr_next;
+	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
+		break;
+	    fr = fr->fr_parent;
+	}
+
+	/*
+	 * Now go downwards to find the bottom or top frame in it.
+	 */
+	for (;;)
+	{
+	    if (nfr->fr_layout == FR_LEAF)
+	    {
+		foundfr = nfr;
+		break;
+	    }
+	    fr = nfr->fr_child;
+	    if (nfr->fr_layout == FR_ROW)
+	    {
+		// Find the frame at the cursor row.
+		while (fr->fr_next != NULL
+			&& frame2win(fr)->w_wincol + fr->fr_width
+					 <= wp->w_wincol + wp->w_wcol)
+		    fr = fr->fr_next;
+	    }
+	    if (nfr->fr_layout == FR_COL && up)
+		while (fr->fr_next != NULL)
+		    fr = fr->fr_next;
+	    nfr = fr;
+	}
+    }
+end:
+    return foundfr != NULL ? foundfr->fr_win : NULL;
+}
+
+/*
+ * Move to window above or below "count" times.
+ */
+    static void
+win_goto_ver(
+    int		up,		// TRUE to go to win above
+    long	count)
+{
+    win_T	*win;
+
+#ifdef FEAT_PROP_POPUP
+    if (ERROR_IF_TERM_POPUP_WINDOW)
+	return;
+#endif
+    win = win_vert_neighbor(curtab, curwin, up, count);
+    if (win != NULL)
+	win_goto(win);
+}
+
+/*
+ * Get the left or right neighbor window of the specified window.
+ *   left - TRUE for the left neighbor
+ *   count - nth neighbor window
+ * Returns the specified window if the neighbor is not found.
+ */
+    win_T *
+win_horz_neighbor(tabpage_T *tp, win_T *wp, int left, long count)
+{
+    frame_T	*fr;
+    frame_T	*nfr;
+    frame_T	*foundfr;
+
+#ifdef FEAT_PROP_POPUP
+    if (popup_is_popup(wp))
+	// popups don't have neighbors.
+	return NULL;
+#endif
+    foundfr = wp->w_frame;
+    while (count--)
+    {
+	/*
+	 * First go upwards in the tree of frames until we find a left or
+	 * right neighbor.
+	 */
+	fr = foundfr;
+	for (;;)
+	{
+	    if (fr == tp->tp_topframe)
+		goto end;
+	    if (left)
+		nfr = fr->fr_prev;
+	    else
+		nfr = fr->fr_next;
+	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
+		break;
+	    fr = fr->fr_parent;
+	}
+
+	/*
+	 * Now go downwards to find the leftmost or rightmost frame in it.
+	 */
+	for (;;)
+	{
+	    if (nfr->fr_layout == FR_LEAF)
+	    {
+		foundfr = nfr;
+		break;
+	    }
+	    fr = nfr->fr_child;
+	    if (nfr->fr_layout == FR_COL)
+	    {
+		// Find the frame at the cursor row.
+		while (fr->fr_next != NULL
+			&& frame2win(fr)->w_winrow + fr->fr_height
+					 <= wp->w_winrow + wp->w_wrow)
+		    fr = fr->fr_next;
+	    }
+	    if (nfr->fr_layout == FR_ROW && left)
+		while (fr->fr_next != NULL)
+		    fr = fr->fr_next;
+	    nfr = fr;
+	}
+    }
+end:
+    return foundfr != NULL ? foundfr->fr_win : NULL;
+}
+
+/*
+ * Move to left or right window.
+ */
+    static void
+win_goto_hor(
+    int		left,		// TRUE to go to left win
+    long	count)
+{
+    win_T	*win;
+
+#ifdef FEAT_PROP_POPUP
+    if (ERROR_IF_TERM_POPUP_WINDOW)
+	return;
+#endif
+    win = win_horz_neighbor(curtab, curwin, left, count);
+    if (win != NULL)
+	win_goto(win);
+}
+
+/*
+ * Make window "wp" the current window.
+ */
+    void
+win_enter(win_T *wp, int undo_sync)
+{
+    (void)win_enter_ext(wp, (undo_sync ? WEE_UNDO_SYNC : 0)
+		    | WEE_TRIGGER_ENTER_AUTOCMDS | WEE_TRIGGER_LEAVE_AUTOCMDS);
+}
+
+/*
+ * Used after making another window the current one: change directory if
+ * needed.
+ */
+    static void
+fix_current_dir(void)
+{
+    if (curwin->w_localdir != NULL || curtab->tp_localdir != NULL)
+    {
+	char_u	*dirname;
+
+	// Window or tab has a local directory: Save current directory as
+	// global directory (unless that was done already) and change to the
+	// local directory.
+	if (globaldir == NULL)
+	{
+	    char_u	cwd[MAXPATHL];
+
+	    if (mch_dirname(cwd, MAXPATHL) == OK)
+		globaldir = vim_strsave(cwd);
+	}
+	if (curwin->w_localdir != NULL)
+	    dirname = curwin->w_localdir;
+	else
+	    dirname = curtab->tp_localdir;
+
+	if (mch_chdir((char *)dirname) == 0)
+	{
+	    last_chdir_reason = NULL;
+	    shorten_fnames(TRUE);
+	}
+    }
+    else if (globaldir != NULL)
+    {
+	// Window doesn't have a local directory and we are not in the global
+	// directory: Change to the global directory.
+	vim_ignored = mch_chdir((char *)globaldir);
+	VIM_CLEAR(globaldir);
+	last_chdir_reason = NULL;
+	shorten_fnames(TRUE);
+    }
+}
+
+/*
+ * Make window "wp" the current window.
+ * Can be called with "flags" containing WEE_CURWIN_INVALID, which means that
+ * curwin has just been closed and isn't valid.
+ * Returns TRUE when dont_parse_messages was decremented.
+ */
+    static int
+win_enter_ext(win_T *wp, int flags)
+{
+    int		other_buffer = FALSE;
+    int		curwin_invalid = (flags & WEE_CURWIN_INVALID);
+    int		did_decrement = FALSE;
+
+    if (wp == curwin && curwin_invalid == 0)	// nothing to do
+	return FALSE;
+
+#ifdef FEAT_JOB_CHANNEL
+    if (curwin_invalid == 0)
+	leaving_window(curwin);
+#endif
+
+    if (curwin_invalid == 0 && (flags & WEE_TRIGGER_LEAVE_AUTOCMDS))
+    {
+	/*
+	 * Be careful: If autocommands delete the window, return now.
+	 */
+	if (wp->w_buffer != curbuf)
+	{
+	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
+	    other_buffer = TRUE;
+	    if (!win_valid(wp))
+		return FALSE;
+	}
+	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
+	if (!win_valid(wp))
+	    return FALSE;
+#ifdef FEAT_EVAL
+	// autocmds may abort script processing
+	if (aborting())
+	    return FALSE;
+#endif
+    }
+
+    // sync undo before leaving the current buffer
+    if ((flags & WEE_UNDO_SYNC) && curbuf != wp->w_buffer)
+	u_sync(FALSE);
+
+    // Might need to scroll the old window before switching, e.g., when the
+    // cursor was moved.
+    if (*p_spk == 'c' && curwin_invalid == 0)
+	update_topline();
+
+    // may have to copy the buffer options when 'cpo' contains 'S'
+    if (wp->w_buffer != curbuf)
+	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
+
+    if (curwin_invalid == 0)
+    {
+	prevwin = curwin;	// remember for CTRL-W p
+	curwin->w_redr_status = TRUE;
+    }
+    else if (wp == prevwin)
+	prevwin = NULL;		// don't want it to be the new curwin
+
+    curwin = wp;
+    curbuf = wp->w_buffer;
+    check_cursor();
+    if (!virtual_active())
+	curwin->w_cursor.coladd = 0;
+    if (*p_spk == 'c')		// assume cursor position needs updating
+	changed_line_abv_curs();
+    else
+	// Make sure the cursor position is valid, either by moving the cursor
+	// or by scrolling the text.
+	win_fix_cursor(
+		get_real_state() & (MODE_NORMAL|MODE_CMDLINE|MODE_TERMINAL));
+
+    // Now it is OK to parse messages again, which may be needed in
+    // autocommands.
+#ifdef MESSAGE_QUEUE
+    if (flags & WEE_ALLOW_PARSE_MESSAGES)
+    {
+	--dont_parse_messages;
+	did_decrement = TRUE;
+    }
+#endif
+
+    fix_current_dir();
+
+#ifdef FEAT_JOB_CHANNEL
+    entering_window(curwin);
+#endif
+    // Careful: autocommands may close the window and make "wp" invalid
+    if (flags & WEE_TRIGGER_NEW_AUTOCMDS)
+	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
+    if (flags & WEE_TRIGGER_ENTER_AUTOCMDS)
+    {
+	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
+	if (other_buffer)
+	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
+    }
+
+    maketitle();
+    curwin->w_redr_status = TRUE;
+#ifdef FEAT_TERMINAL
+    if (bt_terminal(curwin->w_buffer))
+	// terminal is likely in another mode
+	redraw_mode = TRUE;
+#endif
+    redraw_tabline = TRUE;
+    if (restart_edit)
+	redraw_later(UPD_VALID);	// causes status line redraw
+
+    // set window height to desired minimal value
+    if (curwin->w_height < p_wh && !curwin->w_p_wfh
+#ifdef FEAT_PROP_POPUP
+	    && !popup_is_popup(curwin)
+#endif
+	    )
+	win_setheight((int)p_wh);
+    else if (curwin->w_height == 0)
+	win_setheight(1);
+
+    // set window width to desired minimal value
+    if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
+	win_setwidth((int)p_wiw);
+
+    setmouse();			// in case jumped to/from help buffer
+
+    // Change directories when the 'acd' option is set.
+    DO_AUTOCHDIR;
+
+    return did_decrement;
+}
+
+/*
+ * Jump to the first open window that contains buffer "buf", if one exists.
+ * Returns a pointer to the window found, otherwise NULL.
+ */
+    win_T *
+buf_jump_open_win(buf_T *buf)
+{
+    win_T	*wp = NULL;
+
+    if (curwin->w_buffer == buf)
+	wp = curwin;
+    else
+	FOR_ALL_WINDOWS(wp)
+	    if (wp->w_buffer == buf)
+		break;
+    if (wp != NULL)
+	win_enter(wp, FALSE);
+    return wp;
+}
+
+/*
+ * Jump to the first open window in any tab page that contains buffer "buf",
+ * if one exists. First search in the windows present in the current tab page.
+ * Returns a pointer to the window found, otherwise NULL.
+ */
+    win_T *
+buf_jump_open_tab(buf_T *buf)
+{
+    win_T	*wp = buf_jump_open_win(buf);
+    tabpage_T	*tp;
+
+    if (wp != NULL)
+	return wp;
+
+    FOR_ALL_TABPAGES(tp)
+	if (tp != curtab)
+	{
+	    FOR_ALL_WINDOWS_IN_TAB(tp, wp)
+		if (wp->w_buffer == buf)
+		    break;
+	    if (wp != NULL)
+	    {
+		goto_tabpage_win(tp, wp);
+		if (curwin != wp)
+		    wp = NULL;	// something went wrong
+		break;
+	    }
+	}
+    return wp;
+}
+
+static int last_win_id = LOWEST_WIN_ID - 1;
+
+/*
+ * Allocate a window structure and link it in the window list when "hidden" is
+ * FALSE.
+ */
+    static win_T *
+win_alloc(win_T *after, int hidden)
+{
+    win_T	*new_wp;
+
+    /*
+     * allocate window structure and linesizes arrays
+     */
+    new_wp = ALLOC_CLEAR_ONE(win_T);
+    if (new_wp == NULL)
+	return NULL;
+
+    if (win_alloc_lines(new_wp) == FAIL)
+    {
+	vim_free(new_wp);
+	return NULL;
+    }
+
+    new_wp->w_id = ++last_win_id;
+
+#ifdef FEAT_EVAL
+    // init w: variables
+    new_wp->w_vars = dict_alloc_id(aid_newwin_wvars);
+    if (new_wp->w_vars == NULL)
+    {
+	win_free_lsize(new_wp);
+	vim_free(new_wp);
+	return NULL;
+    }
+    init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
+#endif
+
+    // Don't execute autocommands while the window is not properly
+    // initialized yet.  gui_create_scrollbar() may trigger a FocusGained
+    // event.
+    block_autocmds();
+
+    /*
+     * link the window in the window list
+     */
+    if (!hidden)
+	win_append(after, new_wp);
+    new_wp->w_wincol = 0;
+    new_wp->w_width = Columns;
+
+    // position the display and the cursor at the top of the file.
+    new_wp->w_topline = 1;
+#ifdef FEAT_DIFF
+    new_wp->w_topfill = 0;
+#endif
+    new_wp->w_botline = 2;
+    new_wp->w_cursor.lnum = 1;
+    new_wp->w_scbind_pos = 1;
+
+    // use global option value for global-local options
+    new_wp->w_allbuf_opt.wo_so = new_wp->w_p_so = -1;
+    new_wp->w_allbuf_opt.wo_siso = new_wp->w_p_siso = -1;
+
+    // We won't calculate w_fraction until resizing the window
+    new_wp->w_fraction = 0;
+    new_wp->w_prev_fraction_row = -1;
+
+#ifdef FEAT_GUI
+    if (gui.in_use)
+    {
+	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
+		SBAR_LEFT, new_wp);
+	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
+		SBAR_RIGHT, new_wp);
+    }
+#endif
+#ifdef FEAT_FOLDING
+    foldInitWin(new_wp);
+#endif
+    unblock_autocmds();
+#ifdef FEAT_SEARCH_EXTRA
+    new_wp->w_next_match_id = 1000;  // up to 1000 can be picked by the user
+#endif
+    return new_wp;
+}
+
+/*
+ * Remove window 'wp' from the window list and free the structure.
+ */
+    static void
+win_free(
+    win_T	*wp,
+    tabpage_T	*tp)		// tab page "win" is in, NULL for current
+{
+    int		i;
+    buf_T	*buf;
+    wininfo_T	*wip;
+
+#ifdef FEAT_FOLDING
+    clearFolding(wp);
+#endif
+
+    // reduce the reference count to the argument list.
+    alist_unlink(wp->w_alist);
+
+    // Don't execute autocommands while the window is halfway being deleted.
+    // gui_mch_destroy_scrollbar() may trigger a FocusGained event.
+    block_autocmds();
+
+#ifdef FEAT_LUA
+    lua_window_free(wp);
+#endif
+
+#ifdef FEAT_MZSCHEME
+    mzscheme_window_free(wp);
+#endif
+
+#ifdef FEAT_PERL
+    perl_win_free(wp);
+#endif
+
+#ifdef FEAT_PYTHON
+    python_window_free(wp);
+#endif
+
+#ifdef FEAT_PYTHON3
+    python3_window_free(wp);
+#endif
+
+#ifdef FEAT_TCL
+    tcl_window_free(wp);
+#endif
+
+#ifdef FEAT_RUBY
+    ruby_window_free(wp);
+#endif
+
+    clear_winopt(&wp->w_onebuf_opt);
+    clear_winopt(&wp->w_allbuf_opt);
+
+    vim_free(wp->w_lcs_chars.multispace);
+    vim_free(wp->w_lcs_chars.leadmultispace);
+
+#ifdef FEAT_EVAL
+    vars_clear(&wp->w_vars->dv_hashtab);	// free all w: variables
+    hash_init(&wp->w_vars->dv_hashtab);
+    unref_var_dict(wp->w_vars);
+#endif
+
+    {
+	tabpage_T	*ttp;
+
+	if (prevwin == wp)
+	    prevwin = NULL;
+	FOR_ALL_TABPAGES(ttp)
+	    if (ttp->tp_prevwin == wp)
+		ttp->tp_prevwin = NULL;
+    }
+    win_free_lsize(wp);
+
+    for (i = 0; i < wp->w_tagstacklen; ++i)
+    {
+	vim_free(wp->w_tagstack[i].tagname);
+	vim_free(wp->w_tagstack[i].user_data);
+    }
+    vim_free(wp->w_localdir);
+    vim_free(wp->w_prevdir);
+
+    // Remove the window from the b_wininfo lists, it may happen that the
+    // freed memory is re-used for another window.
+    FOR_ALL_BUFFERS(buf)
+	FOR_ALL_BUF_WININFO(buf, wip)
+	    if (wip->wi_win == wp)
+	    {
+		wininfo_T	*wip2;
+
+		// If there already is an entry with "wi_win" set to NULL it
+		// must be removed, it would never be used.
+		// Skip "wip" itself, otherwise Coverity complains.
+		FOR_ALL_BUF_WININFO(buf, wip2)
+		    if (wip2 != wip && wip2->wi_win == NULL)
+		    {
+			if (wip2->wi_next != NULL)
+			    wip2->wi_next->wi_prev = wip2->wi_prev;
+			if (wip2->wi_prev == NULL)
+			    buf->b_wininfo = wip2->wi_next;
+			else
+			    wip2->wi_prev->wi_next = wip2->wi_next;
+			free_wininfo(wip2);
+			break;
+		    }
+
+		wip->wi_win = NULL;
+	    }
+
+#ifdef FEAT_SEARCH_EXTRA
+    clear_matches(wp);
+#endif
+
+    free_jumplist(wp);
+
+#ifdef FEAT_QUICKFIX
+    qf_free_all(wp);
+#endif
+
+#ifdef FEAT_GUI
+    if (gui.in_use)
+    {
+	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
+	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
+    }
+#endif // FEAT_GUI
+
+#ifdef FEAT_MENU
+    remove_winbar(wp);
+#endif
+#ifdef FEAT_PROP_POPUP
+    free_callback(&wp->w_close_cb);
+    free_callback(&wp->w_filter_cb);
+    for (i = 0; i < 4; ++i)
+	VIM_CLEAR(wp->w_border_highlight[i]);
+    vim_free(wp->w_scrollbar_highlight);
+    vim_free(wp->w_thumb_highlight);
+    vim_free(wp->w_popup_title);
+    list_unref(wp->w_popup_mask);
+    vim_free(wp->w_popup_mask_cells);
+#endif
+
+#ifdef FEAT_SYN_HL
+    vim_free(wp->w_p_cc_cols);
+#endif
+
+    if (win_valid_any_tab(wp))
+	win_remove(wp, tp);
+    if (autocmd_busy)
+    {
+	wp->w_next = au_pending_free_win;
+	au_pending_free_win = wp;
+    }
+    else
+	vim_free(wp);
+
+    unblock_autocmds();
+}
+
+/*
+ * Return TRUE if "wp" is not in the list of windows: the autocmd window or a
+ * popup window.
+ */
+    int
+win_unlisted(win_T *wp)
+{
+    return is_aucmd_win(wp) || WIN_IS_POPUP(wp);
+}
+
+#if defined(FEAT_PROP_POPUP) || defined(PROTO)
+/*
+ * Free a popup window.  This does not take the window out of the window list
+ * and assumes there is only one toplevel frame, no split.
+ */
+    void
+win_free_popup(win_T *win)
+{
+    if (win->w_buffer != NULL)
+    {
+	if (bt_popup(win->w_buffer))
+	    win_close_buffer(win, DOBUF_WIPE_REUSE, FALSE);
+	else
+	    close_buffer(win, win->w_buffer, 0, FALSE, FALSE);
+    }
+# if defined(FEAT_TIMERS)
+    // the timer may have been cleared, making the pointer invalid
+    if (timer_valid(win->w_popup_timer))
+	stop_timer(win->w_popup_timer);
+# endif
+    vim_free(win->w_frame);
+    win_free(win, NULL);
+}
+#endif
+
+/*
+ * Append window "wp" in the window list after window "after".
+ */
+    static void
+win_append(win_T *after, win_T *wp)
+{
+    win_T	*before;
+
+    if (after == NULL)	    // after NULL is in front of the first
+	before = firstwin;
+    else
+	before = after->w_next;
+
+    wp->w_next = before;
+    wp->w_prev = after;
+    if (after == NULL)
+	firstwin = wp;
+    else
+	after->w_next = wp;
+    if (before == NULL)
+	lastwin = wp;
+    else
+	before->w_prev = wp;
+}
+
+/*
+ * Remove a window from the window list.
+ */
+    void
+win_remove(
+    win_T	*wp,
+    tabpage_T	*tp)		// tab page "win" is in, NULL for current
+{
+    if (wp->w_prev != NULL)
+	wp->w_prev->w_next = wp->w_next;
+    else if (tp == NULL)
+	firstwin = curtab->tp_firstwin = wp->w_next;
+    else
+	tp->tp_firstwin = wp->w_next;
+
+    if (wp->w_next != NULL)
+	wp->w_next->w_prev = wp->w_prev;
+    else if (tp == NULL)
+	lastwin = curtab->tp_lastwin = wp->w_prev;
+    else
+	tp->tp_lastwin = wp->w_prev;
+}
+
+/*
+ * Append frame "frp" in a frame list after frame "after".
+ */
+    static void
+frame_append(frame_T *after, frame_T *frp)
+{
+    frp->fr_next = after->fr_next;
+    after->fr_next = frp;
+    if (frp->fr_next != NULL)
+	frp->fr_next->fr_prev = frp;
+    frp->fr_prev = after;
+}
+
+/*
+ * Insert frame "frp" in a frame list before frame "before".
+ */
+    static void
+frame_insert(frame_T *before, frame_T *frp)
+{
+    frp->fr_next = before;
+    frp->fr_prev = before->fr_prev;
+    before->fr_prev = frp;
+    if (frp->fr_prev != NULL)
+	frp->fr_prev->fr_next = frp;
+    else
+	frp->fr_parent->fr_child = frp;
+}
+
+/*
+ * Remove a frame from a frame list.
+ */
+    static void
+frame_remove(frame_T *frp)
+{
+    if (frp->fr_prev != NULL)
+	frp->fr_prev->fr_next = frp->fr_next;
+    else
+	frp->fr_parent->fr_child = frp->fr_next;
+    if (frp->fr_next != NULL)
+	frp->fr_next->fr_prev = frp->fr_prev;
+}
+
+/*
+ * Allocate w_lines[] for window "wp".
+ * Return FAIL for failure, OK for success.
+ */
+    int
+win_alloc_lines(win_T *wp)
+{
+    wp->w_lines_valid = 0;
+    wp->w_lines = ALLOC_CLEAR_MULT(wline_T, Rows);
+    if (wp->w_lines == NULL)
+	return FAIL;
+    return OK;
+}
+
+/*
+ * free lsize arrays for a window
+ */
+    void
+win_free_lsize(win_T *wp)
+{
+    // TODO: why would wp be NULL here?
+    if (wp != NULL)
+	VIM_CLEAR(wp->w_lines);
+}
+
+/*
+ * Called from win_new_shellsize() after Rows changed.
+ * This only does the current tab page, others must be done when made active.
+ */
+    void
+shell_new_rows(void)
+{
+    int		h = (int)ROWS_AVAIL;
+
+    if (firstwin == NULL)	// not initialized yet
+	return;
+    if (h < frame_minheight(topframe, NULL))
+	h = frame_minheight(topframe, NULL);
+
+    // First try setting the heights of windows with 'winfixheight'.  If
+    // that doesn't result in the right height, forget about that option.
+    frame_new_height(topframe, h, FALSE, TRUE);
+    if (!frame_check_height(topframe, h))
+	frame_new_height(topframe, h, FALSE, FALSE);
+
+    (void)win_comp_pos();		// recompute w_winrow and w_wincol
+    compute_cmdrow();
+    curtab->tp_ch_used = p_ch;
+
+    if (!skip_win_fix_scroll)
+	win_fix_scroll(TRUE);
+
+#if 0
+    // Disabled: don't want making the screen smaller make a window larger.
+    if (p_ea)
+	win_equal(curwin, FALSE, 'v');
+#endif
+}
+
+/*
+ * Called from win_new_shellsize() after Columns changed.
+ */
+    void
+shell_new_columns(void)
+{
+    if (firstwin == NULL)	// not initialized yet
+	return;
+
+    // First try setting the widths of windows with 'winfixwidth'.  If that
+    // doesn't result in the right width, forget about that option.
+    frame_new_width(topframe, (int)Columns, FALSE, TRUE);
+    if (!frame_check_width(topframe, Columns))
+	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
+
+    (void)win_comp_pos();		// recompute w_winrow and w_wincol
+#if 0
+    // Disabled: don't want making the screen smaller make a window larger.
+    if (p_ea)
+	win_equal(curwin, FALSE, 'h');
+#endif
+}
+
+/*
+ * Save the size of all windows in "gap".
+ */
+    void
+win_size_save(garray_T *gap)
+{
+    win_T	*wp;
+
+    ga_init2(gap, sizeof(int), 1);
+    if (ga_grow(gap, win_count() * 2 + 1) == FAIL)
+	return;
+
+    // first entry is the total lines available for windows
+    ((int *)gap->ga_data)[gap->ga_len++] = ROWS_AVAIL - last_stl_height(FALSE);
+
+    FOR_ALL_WINDOWS(wp)
+    {
+	((int *)gap->ga_data)[gap->ga_len++] =
+	    wp->w_width + wp->w_vsep_width;
+	((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
+    }
+}
+
+/*
+ * Restore window sizes, but only if the number of windows is still the same
+ * and total lines available for windows didn't change.
+ * Does not free the growarray.
+ */
+    void
+win_size_restore(garray_T *gap)
+{
+    win_T	*wp;
+    int		i, j;
+
+    if (win_count() * 2 + 1 == gap->ga_len
+	    && ((int *)gap->ga_data)[0] == ROWS_AVAIL - last_stl_height(FALSE))
+    {
+	// The order matters, because frames contain other frames, but it's
+	// difficult to get right. The easy way out is to do it twice.
+	for (j = 0; j < 2; ++j)
+	{
+	    i = 1;
+	    FOR_ALL_WINDOWS(wp)
+	    {
+		frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
+		win_setheight_win(((int *)gap->ga_data)[i++], wp);
+	    }
+	}
+	// recompute the window positions
+	(void)win_comp_pos();
+    }
+}
+
+/*
+ * Update the position for all windows, using the width and height of the
+ * frames.
+ * Returns the row just after the last window.
+ */
+    int
+win_comp_pos(void)
+{
+    int		row = tabline_height();
+    int		col = 0;
+
+    frame_comp_pos(topframe, &row, &col);
+    return row;
+}
+
+/*
+ * Update the position of the windows in frame "topfrp", using the width and
+ * height of the frames.
+ * "*row" and "*col" are the top-left position of the frame.  They are updated
+ * to the bottom-right position plus one.
+ */
+    static void
+frame_comp_pos(frame_T *topfrp, int *row, int *col)
+{
+    win_T	*wp;
+    frame_T	*frp;
+    int		startcol;
+    int		startrow;
+    int		h;
+
+    wp = topfrp->fr_win;
+    if (wp != NULL)
+    {
+	if (wp->w_winrow != *row || wp->w_wincol != *col)
+	{
+	    // position changed, redraw
+	    wp->w_winrow = *row;
+	    wp->w_wincol = *col;
+	    redraw_win_later(wp, UPD_NOT_VALID);
+	    wp->w_redr_status = TRUE;
+	}
+	// WinBar will not show if the window height is zero
+	h = VISIBLE_HEIGHT(wp) + wp->w_status_height;
+	*row += h > topfrp->fr_height ? topfrp->fr_height : h;
+	*col += wp->w_width + wp->w_vsep_width;
+    }
+    else
+    {
+	startrow = *row;
+	startcol = *col;
+	FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	{
+	    if (topfrp->fr_layout == FR_ROW)
+		*row = startrow;	// all frames are at the same row
+	    else
+		*col = startcol;	// all frames are at the same col
+	    frame_comp_pos(frp, row, col);
+	}
+    }
+}
+
+/*
+ * Make the current window show at least one line and one column.
+ */
+    void
+win_ensure_size(void)
+{
+    if (curwin->w_height == 0)
+	win_setheight(1);
+    if (curwin->w_width == 0)
+	win_setwidth(1);
+}
+
+/*
+ * Set current window height and take care of repositioning other windows to
+ * fit around it.
+ */
+    void
+win_setheight(int height)
+{
+    win_setheight_win(height, curwin);
+}
+
+/*
+ * Set the window height of window "win" and take care of repositioning other
+ * windows to fit around it.
+ */
+    void
+win_setheight_win(int height, win_T *win)
+{
+    int		row;
+
+    if (win == curwin)
+    {
+	// Always keep current window at least one line high, even when
+	// 'winminheight' is zero.
+	if (height < p_wmh)
+	    height = p_wmh;
+	if (height == 0)
+	    height = 1;
+	height += WINBAR_HEIGHT(curwin);
+    }
+
+    frame_setheight(win->w_frame, height + win->w_status_height);
+
+    // recompute the window positions
+    row = win_comp_pos();
+
+    /*
+     * If there is extra space created between the last window and the command
+     * line, clear it.
+     */
+    if (full_screen && msg_scrolled == 0 && row < cmdline_row)
+	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
+    cmdline_row = row;
+    msg_row = row;
+    msg_col = 0;
+
+    win_fix_scroll(TRUE);
+
+    redraw_all_later(UPD_NOT_VALID);
+}
+
+/*
+ * Set the height of a frame to "height" and take care that all frames and
+ * windows inside it are resized.  Also resize frames on the left and right if
+ * the are in the same FR_ROW frame.
+ *
+ * Strategy:
+ * If the frame is part of a FR_COL frame, try fitting the frame in that
+ * frame.  If that doesn't work (the FR_COL frame is too small), recursively
+ * go to containing frames to resize them and make room.
+ * If the frame is part of a FR_ROW frame, all frames must be resized as well.
+ * Check for the minimal height of the FR_ROW frame.
+ * At the top level we can also use change the command line height.
+ */
+    static void
+frame_setheight(frame_T *curfrp, int height)
+{
+    int		room;		// total number of lines available
+    int		take;		// number of lines taken from other windows
+    int		room_cmdline;	// lines available from cmdline
+    int		run;
+    frame_T	*frp;
+    int		h;
+    int		room_reserved;
+
+    // If the height already is the desired value, nothing to do.
+    if (curfrp->fr_height == height)
+	return;
+
+    if (curfrp->fr_parent == NULL)
+    {
+	// topframe: can only change the command line height
+	if (height > ROWS_AVAIL)
+	    height = ROWS_AVAIL;
+	if (height > 0)
+	    frame_new_height(curfrp, height, FALSE, FALSE);
+    }
+    else if (curfrp->fr_parent->fr_layout == FR_ROW)
+    {
+	// Row of frames: Also need to resize frames left and right of this
+	// one.  First check for the minimal height of these.
+	h = frame_minheight(curfrp->fr_parent, NULL);
+	if (height < h)
+	    height = h;
+	frame_setheight(curfrp->fr_parent, height);
+    }
+    else
+    {
+	/*
+	 * Column of frames: try to change only frames in this column.
+	 */
+	/*
+	 * Do this twice:
+	 * 1: compute room available, if it's not enough try resizing the
+	 *    containing frame.
+	 * 2: compute the room available and adjust the height to it.
+	 * Try not to reduce the height of a window with 'winfixheight' set.
+	 */
+	for (run = 1; run <= 2; ++run)
+	{
+	    room = 0;
+	    room_reserved = 0;
+	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
+	    {
+		if (frp != curfrp
+			&& frp->fr_win != NULL
+			&& frp->fr_win->w_p_wfh)
+		    room_reserved += frp->fr_height;
+		room += frp->fr_height;
+		if (frp != curfrp)
+		    room -= frame_minheight(frp, NULL);
+	    }
+	    if (curfrp->fr_width != Columns)
+		room_cmdline = 0;
+	    else
+	    {
+		room_cmdline = Rows - p_ch - (lastwin->w_winrow
+						+ VISIBLE_HEIGHT(lastwin)
+						+ lastwin->w_status_height);
+		if (room_cmdline < 0)
+		    room_cmdline = 0;
+	    }
+
+	    if (height <= room + room_cmdline)
+		break;
+	    if (run == 2 || curfrp->fr_width == Columns)
+	    {
+		height = room + room_cmdline;
+		break;
+	    }
+	    frame_setheight(curfrp->fr_parent, height
+		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
+	}
+
+	/*
+	 * Compute the number of lines we will take from others frames (can be
+	 * negative!).
+	 */
+	take = height - curfrp->fr_height;
+
+	// If there is not enough room, also reduce the height of a window
+	// with 'winfixheight' set.
+	if (height > room + room_cmdline - room_reserved)
+	    room_reserved = room + room_cmdline - height;
+	// If there is only a 'winfixheight' window and making the
+	// window smaller, need to make the other window taller.
+	if (take < 0 && room - curfrp->fr_height < room_reserved)
+	    room_reserved = 0;
+
+	if (take > 0 && room_cmdline > 0)
+	{
+	    // use lines from cmdline first
+	    if (take < room_cmdline)
+		room_cmdline = take;
+	    take -= room_cmdline;
+	    topframe->fr_height += room_cmdline;
+	}
+
+	/*
+	 * set the current frame to the new height
+	 */
+	frame_new_height(curfrp, height, FALSE, FALSE);
+
+	/*
+	 * First take lines from the frames after the current frame.  If
+	 * that is not enough, takes lines from frames above the current
+	 * frame.
+	 */
+	for (run = 0; run < 2; ++run)
+	{
+	    if (run == 0)
+		frp = curfrp->fr_next;	// 1st run: start with next window
+	    else
+		frp = curfrp->fr_prev;	// 2nd run: start with prev window
+	    while (frp != NULL && take != 0)
+	    {
+		h = frame_minheight(frp, NULL);
+		if (room_reserved > 0
+			&& frp->fr_win != NULL
+			&& frp->fr_win->w_p_wfh)
+		{
+		    if (room_reserved >= frp->fr_height)
+			room_reserved -= frp->fr_height;
+		    else
+		    {
+			if (frp->fr_height - room_reserved > take)
+			    room_reserved = frp->fr_height - take;
+			take -= frp->fr_height - room_reserved;
+			frame_new_height(frp, room_reserved, FALSE, FALSE);
+			room_reserved = 0;
+		    }
+		}
+		else
+		{
+		    if (frp->fr_height - take < h)
+		    {
+			take -= frp->fr_height - h;
+			frame_new_height(frp, h, FALSE, FALSE);
+		    }
+		    else
+		    {
+			frame_new_height(frp, frp->fr_height - take,
+								FALSE, FALSE);
+			take = 0;
+		    }
+		}
+		if (run == 0)
+		    frp = frp->fr_next;
+		else
+		    frp = frp->fr_prev;
+	    }
+	}
+    }
+}
+
+/*
+ * Set current window width and take care of repositioning other windows to
+ * fit around it.
+ */
+    void
+win_setwidth(int width)
+{
+    win_setwidth_win(width, curwin);
+}
+
+    void
+win_setwidth_win(int width, win_T *wp)
+{
+    // Always keep current window at least one column wide, even when
+    // 'winminwidth' is zero.
+    if (wp == curwin)
+    {
+	if (width < p_wmw)
+	    width = p_wmw;
+	if (width == 0)
+	    width = 1;
+    }
+    else if (width < 0)
+	width = 0;
+
+    frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
+
+    // recompute the window positions
+    (void)win_comp_pos();
+
+    redraw_all_later(UPD_NOT_VALID);
+}
+
+/*
+ * Set the width of a frame to "width" and take care that all frames and
+ * windows inside it are resized.  Also resize frames above and below if the
+ * are in the same FR_ROW frame.
+ *
+ * Strategy is similar to frame_setheight().
+ */
+    static void
+frame_setwidth(frame_T *curfrp, int width)
+{
+    int		room;		// total number of lines available
+    int		take;		// number of lines taken from other windows
+    int		run;
+    frame_T	*frp;
+    int		w;
+    int		room_reserved;
+
+    // If the width already is the desired value, nothing to do.
+    if (curfrp->fr_width == width)
+	return;
+
+    if (curfrp->fr_parent == NULL)
+	// topframe: can't change width
+	return;
+
+    if (curfrp->fr_parent->fr_layout == FR_COL)
+    {
+	// Column of frames: Also need to resize frames above and below of
+	// this one.  First check for the minimal width of these.
+	w = frame_minwidth(curfrp->fr_parent, NULL);
+	if (width < w)
+	    width = w;
+	frame_setwidth(curfrp->fr_parent, width);
+    }
+    else
+    {
+	/*
+	 * Row of frames: try to change only frames in this row.
+	 *
+	 * Do this twice:
+	 * 1: compute room available, if it's not enough try resizing the
+	 *    containing frame.
+	 * 2: compute the room available and adjust the width to it.
+	 */
+	for (run = 1; run <= 2; ++run)
+	{
+	    room = 0;
+	    room_reserved = 0;
+	    FOR_ALL_FRAMES(frp, curfrp->fr_parent->fr_child)
+	    {
+		if (frp != curfrp
+			&& frp->fr_win != NULL
+			&& frp->fr_win->w_p_wfw)
+		    room_reserved += frp->fr_width;
+		room += frp->fr_width;
+		if (frp != curfrp)
+		    room -= frame_minwidth(frp, NULL);
+	    }
+
+	    if (width <= room)
+		break;
+	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
+	    {
+		width = room;
+		break;
+	    }
+	    frame_setwidth(curfrp->fr_parent, width
+		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
+	}
+
+	/*
+	 * Compute the number of lines we will take from others frames (can be
+	 * negative!).
+	 */
+	take = width - curfrp->fr_width;
+
+	// If there is not enough room, also reduce the width of a window
+	// with 'winfixwidth' set.
+	if (width > room - room_reserved)
+	    room_reserved = room - width;
+	// If there is only a 'winfixwidth' window and making the
+	// window smaller, need to make the other window narrower.
+	if (take < 0 && room - curfrp->fr_width < room_reserved)
+	    room_reserved = 0;
+
+	/*
+	 * set the current frame to the new width
+	 */
+	frame_new_width(curfrp, width, FALSE, FALSE);
+
+	/*
+	 * First take lines from the frames right of the current frame.  If
+	 * that is not enough, takes lines from frames left of the current
+	 * frame.
+	 */
+	for (run = 0; run < 2; ++run)
+	{
+	    if (run == 0)
+		frp = curfrp->fr_next;	// 1st run: start with next window
+	    else
+		frp = curfrp->fr_prev;	// 2nd run: start with prev window
+	    while (frp != NULL && take != 0)
+	    {
+		w = frame_minwidth(frp, NULL);
+		if (room_reserved > 0
+			&& frp->fr_win != NULL
+			&& frp->fr_win->w_p_wfw)
+		{
+		    if (room_reserved >= frp->fr_width)
+			room_reserved -= frp->fr_width;
+		    else
+		    {
+			if (frp->fr_width - room_reserved > take)
+			    room_reserved = frp->fr_width - take;
+			take -= frp->fr_width - room_reserved;
+			frame_new_width(frp, room_reserved, FALSE, FALSE);
+			room_reserved = 0;
+		    }
+		}
+		else
+		{
+		    if (frp->fr_width - take < w)
+		    {
+			take -= frp->fr_width - w;
+			frame_new_width(frp, w, FALSE, FALSE);
+		    }
+		    else
+		    {
+			frame_new_width(frp, frp->fr_width - take,
+								FALSE, FALSE);
+			take = 0;
+		    }
+		}
+		if (run == 0)
+		    frp = frp->fr_next;
+		else
+		    frp = frp->fr_prev;
+	    }
+	}
+    }
+}
+
+/*
+ * Check 'winminheight' for a valid value and reduce it if needed.
+ */
+    void
+win_setminheight(void)
+{
+    int		room;
+    int		needed;
+    int		first = TRUE;
+
+    // loop until there is a 'winminheight' that is possible
+    while (p_wmh > 0)
+    {
+	room = Rows - p_ch;
+	needed = min_rows() - 1;  // 1 was added for the cmdline
+	if (room >= needed)
+	    break;
+	--p_wmh;
+	if (first)
+	{
+	    emsg(_(e_not_enough_room));
+	    first = FALSE;
+	}
+    }
+}
+
+/*
+ * Check 'winminwidth' for a valid value and reduce it if needed.
+ */
+    void
+win_setminwidth(void)
+{
+    int		room;
+    int		needed;
+    int		first = TRUE;
+
+    // loop until there is a 'winminheight' that is possible
+    while (p_wmw > 0)
+    {
+	room = Columns;
+	needed = frame_minwidth(topframe, NULL);
+	if (room >= needed)
+	    break;
+	--p_wmw;
+	if (first)
+	{
+	    emsg(_(e_not_enough_room));
+	    first = FALSE;
+	}
+    }
+}
+
+/*
+ * Status line of dragwin is dragged "offset" lines down (negative is up).
+ */
+    void
+win_drag_status_line(win_T *dragwin, int offset)
+{
+    frame_T	*curfr;
+    frame_T	*fr;
+    int		room;
+    int		row;
+    int		up;	// if TRUE, drag status line up, otherwise down
+    int		n;
+
+    fr = dragwin->w_frame;
+    curfr = fr;
+    if (fr != topframe)		// more than one window
+    {
+	fr = fr->fr_parent;
+	// When the parent frame is not a column of frames, its parent should
+	// be.
+	if (fr->fr_layout != FR_COL)
+	{
+	    curfr = fr;
+	    if (fr != topframe)	// only a row of windows, may drag statusline
+		fr = fr->fr_parent;
+	}
+    }
+
+    // If this is the last frame in a column, may want to resize the parent
+    // frame instead (go two up to skip a row of frames).
+    while (curfr != topframe && curfr->fr_next == NULL)
+    {
+	if (fr != topframe)
+	    fr = fr->fr_parent;
+	curfr = fr;
+	if (fr != topframe)
+	    fr = fr->fr_parent;
+    }
+
+    if (offset < 0) // drag up
+    {
+	up = TRUE;
+	offset = -offset;
+	// sum up the room of the current frame and above it
+	if (fr == curfr)
+	{
+	    // only one window
+	    room = fr->fr_height - frame_minheight(fr, NULL);
+	}
+	else
+	{
+	    room = 0;
+	    for (fr = fr->fr_child; ; fr = fr->fr_next)
+	    {
+		room += fr->fr_height - frame_minheight(fr, NULL);
+		if (fr == curfr)
+		    break;
+	    }
+	}
+	fr = curfr->fr_next;		// put fr at frame that grows
+    }
+    else    // drag down
+    {
+	up = FALSE;
+	/*
+	 * Only dragging the last status line can reduce p_ch.
+	 */
+	room = Rows - cmdline_row;
+	if (curfr->fr_next == NULL)
+	    --room;
+	else
+	    room -= p_ch;
+	if (room < 0)
+	    room = 0;
+	// sum up the room of frames below of the current one
+	FOR_ALL_FRAMES(fr, curfr->fr_next)
+	    room += fr->fr_height - frame_minheight(fr, NULL);
+	fr = curfr;			// put fr at window that grows
+    }
+
+    if (room < offset)		// Not enough room
+	offset = room;		// Move as far as we can
+    if (offset <= 0)
+	return;
+
+    /*
+     * Grow frame fr by "offset" lines.
+     * Doesn't happen when dragging the last status line up.
+     */
+    if (fr != NULL)
+	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
+
+    if (up)
+	fr = curfr;		// current frame gets smaller
+    else
+	fr = curfr->fr_next;	// next frame gets smaller
+
+    /*
+     * Now make the other frames smaller.
+     */
+    while (fr != NULL && offset > 0)
+    {
+	n = frame_minheight(fr, NULL);
+	if (fr->fr_height - offset <= n)
+	{
+	    offset -= fr->fr_height - n;
+	    frame_new_height(fr, n, !up, FALSE);
+	}
+	else
+	{
+	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
+	    break;
+	}
+	if (up)
+	    fr = fr->fr_prev;
+	else
+	    fr = fr->fr_next;
+    }
+    row = win_comp_pos();
+    screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
+    cmdline_row = row;
+    p_ch = MAX(Rows - cmdline_row, 1);
+    curtab->tp_ch_used = p_ch;
+
+    win_fix_scroll(TRUE);
+
+    redraw_all_later(UPD_SOME_VALID);
+    showmode();
+}
+
+/*
+ * Separator line of dragwin is dragged "offset" lines right (negative is left).
+ */
+    void
+win_drag_vsep_line(win_T *dragwin, int offset)
+{
+    frame_T	*curfr;
+    frame_T	*fr;
+    int		room;
+    int		left;	// if TRUE, drag separator line left, otherwise right
+    int		n;
+
+    fr = dragwin->w_frame;
+    if (fr == topframe)		// only one window (cannot happen?)
+	return;
+    curfr = fr;
+    fr = fr->fr_parent;
+    // When the parent frame is not a row of frames, its parent should be.
+    if (fr->fr_layout != FR_ROW)
+    {
+	if (fr == topframe)	// only a column of windows (cannot happen?)
+	    return;
+	curfr = fr;
+	fr = fr->fr_parent;
+    }
+
+    // If this is the last frame in a row, may want to resize a parent
+    // frame instead.
+    while (curfr->fr_next == NULL)
+    {
+	if (fr == topframe)
+	    break;
+	curfr = fr;
+	fr = fr->fr_parent;
+	if (fr != topframe)
+	{
+	    curfr = fr;
+	    fr = fr->fr_parent;
+	}
+    }
+
+    if (offset < 0) // drag left
+    {
+	left = TRUE;
+	offset = -offset;
+	// sum up the room of the current frame and left of it
+	room = 0;
+	for (fr = fr->fr_child; ; fr = fr->fr_next)
+	{
+	    room += fr->fr_width - frame_minwidth(fr, NULL);
+	    if (fr == curfr)
+		break;
+	}
+	fr = curfr->fr_next;		// put fr at frame that grows
+    }
+    else    // drag right
+    {
+	left = FALSE;
+	// sum up the room of frames right of the current one
+	room = 0;
+	FOR_ALL_FRAMES(fr, curfr->fr_next)
+	    room += fr->fr_width - frame_minwidth(fr, NULL);
+	fr = curfr;			// put fr at window that grows
+    }
+
+    if (room < offset)		// Not enough room
+	offset = room;		// Move as far as we can
+    if (offset <= 0)		// No room at all, quit.
+	return;
+    if (fr == NULL)
+	// This can happen when calling win_move_separator() on the rightmost
+	// window.  Just don't do anything.
+	return;
+
+    // grow frame fr by offset lines
+    frame_new_width(fr, fr->fr_width + offset, left, FALSE);
+
+    // shrink other frames: current and at the left or at the right
+    if (left)
+	fr = curfr;		// current frame gets smaller
+    else
+	fr = curfr->fr_next;	// next frame gets smaller
+
+    while (fr != NULL && offset > 0)
+    {
+	n = frame_minwidth(fr, NULL);
+	if (fr->fr_width - offset <= n)
+	{
+	    offset -= fr->fr_width - n;
+	    frame_new_width(fr, n, !left, FALSE);
+	}
+	else
+	{
+	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
+	    break;
+	}
+	if (left)
+	    fr = fr->fr_prev;
+	else
+	    fr = fr->fr_next;
+    }
+    (void)win_comp_pos();
+    redraw_all_later(UPD_NOT_VALID);
+}
+
+#define FRACTION_MULT	16384L
+
+/*
+ * Set wp->w_fraction for the current w_wrow and w_height.
+ * Has no effect when the window is less than two lines.
+ */
+    void
+set_fraction(win_T *wp)
+{
+    if (wp->w_height > 1)
+	// When cursor is in the first line the percentage is computed as if
+	// it's halfway that line.  Thus with two lines it is 25%, with three
+	// lines 17%, etc.  Similarly for the last line: 75%, 83%, etc.
+	wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
+				     + FRACTION_MULT / 2) / (long)wp->w_height;
+}
+
+/*
+ * Handle scroll position, depending on 'splitkeep'.  Replaces the
+ * scroll_to_fraction() call from win_new_height() if 'splitkeep' is "screen"
+ * or "topline".  Instead we iterate over all windows in a tabpage and
+ * calculate the new scroll position.
+ * TODO: Ensure this also works with wrapped lines.
+ * Requires a not fully visible cursor line to be allowed at the bottom of
+ * a window("zb"), probably only when 'smoothscroll' is also set.
+ */
+    static void
+win_fix_scroll(int resize)
+{
+    if (*p_spk == 'c')
+	return;  // 'splitkeep' is "cursor"
+
+    skip_update_topline = TRUE;
+    win_T	*wp;
+    FOR_ALL_WINDOWS(wp)
+    {
+	// Skip when window height has not changed.
+	if (wp->w_height != wp->w_prev_height)
+	{
+	    // Cursor position in this window may now be invalid.  It is kept
+	    // potentially invalid until the window is made the current window.
+	    wp->w_do_win_fix_cursor = TRUE;
+
+	    // If window has moved update botline to keep the same screenlines.
+	    if (*p_spk == 's' && wp->w_winrow != wp->w_prev_winrow
+		      && wp->w_botline - 1 <= wp->w_buffer->b_ml.ml_line_count)
+	    {
+		int diff = (wp->w_winrow - wp->w_prev_winrow)
+					  + (wp->w_height - wp->w_prev_height);
+		linenr_T lnum = wp->w_cursor.lnum;
+		wp->w_cursor.lnum = wp->w_botline - 1;
+
+		//  Add difference in height and row to botline.
+		if (diff > 0)
+		    cursor_down_inner(wp, diff);
+		else
+		    cursor_up_inner(wp, -diff);
+
+		// Scroll to put the new cursor position at the bottom of the
+		// screen.
+		wp->w_fraction = FRACTION_MULT;
+		scroll_to_fraction(wp, wp->w_prev_height);
+
+		wp->w_cursor.lnum = lnum;
+	    }
+	    else if (wp == curwin)
+		wp->w_valid &= ~VALID_CROW;
+
+	    invalidate_botline_win(wp);
+	    validate_botline_win(wp);
+	}
+	wp->w_prev_height = wp->w_height;
+	wp->w_prev_winrow = wp->w_winrow;
+    }
+    skip_update_topline = FALSE;
+    // Ensure cursor is valid when not in normal mode or when resized.
+    if (!(get_real_state() & (MODE_NORMAL|MODE_CMDLINE|MODE_TERMINAL)))
+	win_fix_cursor(FALSE);
+    else if (resize)
+	win_fix_cursor(TRUE);
+}
+
+/*
+ * Make sure the cursor position is valid for 'splitkeep'.
+ * If it is not, put the cursor position in the jumplist and move it.
+ * If we are not in normal mode ("normal" is FALSE), make it valid by scrolling
+ * instead.
+ */
+    static void
+win_fix_cursor(int normal)
+{
+    win_T	*wp = curwin;
+
+    if (skip_win_fix_cursor
+	    || !wp->w_do_win_fix_cursor
+	    || wp->w_buffer->b_ml.ml_line_count < wp->w_height)
+	return;
+
+    wp->w_do_win_fix_cursor = FALSE;
+    // Determine valid cursor range.
+    long so = MIN(wp->w_height / 2, get_scrolloff_value());
+    linenr_T lnum = wp->w_cursor.lnum;
+
+    wp->w_cursor.lnum = wp->w_topline;
+    cursor_down_inner(wp, so);
+    linenr_T top = wp->w_cursor.lnum;
+
+    wp->w_cursor.lnum = wp->w_botline - 1;
+    cursor_up_inner(wp, so);
+    linenr_T bot = wp->w_cursor.lnum;
+
+    wp->w_cursor.lnum = lnum;
+
+    // Check if cursor position is above or below valid cursor range.
+    linenr_T nlnum = 0;
+    if (lnum > bot && (wp->w_botline - wp->w_buffer->b_ml.ml_line_count) != 1)
+	nlnum = bot;
+    else if (lnum < top && wp->w_topline != 1)
+	nlnum = (so == wp->w_height / 2) ? bot : top;
+
+    if (nlnum != 0)  // Cursor is invalid for current scroll position.
+    {
+	if (normal)  // Save to jumplist and set cursor to avoid scrolling.
+	{
+	    setmark('\'');
+	    wp->w_cursor.lnum = nlnum;
+	}
+	else  // Scroll instead when not in normal mode.
+	{
+	    wp->w_fraction = (nlnum == bot) ? FRACTION_MULT : 0;
+	    scroll_to_fraction(wp, wp->w_prev_height);
+	    validate_botline();
+	}
+    }
+}
+
+/*
+ * Set the height of a window.
+ * "height" excludes any window toolbar.
+ * This takes care of the things inside the window, not what happens to the
+ * window position, the frame or to other windows.
+ */
+    void
+win_new_height(win_T *wp, int height)
+{
+    int		prev_height = wp->w_height;
+
+    // Don't want a negative height.  Happens when splitting a tiny window.
+    // Will equalize heights soon to fix it.
+    if (height < 0)
+	height = 0;
+    if (wp->w_height == height)
+	return;	    // nothing to do
+
+    if (wp->w_height > 0)
+    {
+	if (wp == curwin && *p_spk == 'c')
+	    // w_wrow needs to be valid. When setting 'laststatus' this may
+	    // call win_new_height() recursively.
+	    validate_cursor();
+	if (wp->w_height != prev_height)
+	    return;  // Recursive call already changed the size, bail out here
+		     //	to avoid the following to mess things up.
+	if (wp->w_wrow != wp->w_prev_fraction_row)
+	    set_fraction(wp);
+    }
+
+    wp->w_height = height;
+    wp->w_redr_status = TRUE;
+    win_comp_scroll(wp);
+
+    // There is no point in adjusting the scroll position when exiting.  Some
+    // values might be invalid.
+    if (!exiting && *p_spk == 'c')
+    {
+	wp->w_skipcol = 0;
+	scroll_to_fraction(wp, prev_height);
+    }
+}
+
+    void
+scroll_to_fraction(win_T *wp, int prev_height)
+{
+    linenr_T	lnum;
+    int		sline, line_size;
+    int		height = wp->w_height;
+
+    // Don't change w_topline in any of these cases:
+    // - window height is 0
+    // - 'scrollbind' is set and this isn't the current window
+    // - window height is sufficient to display the whole buffer and first line
+    //   is visible.
+    if (height > 0
+	   && (!wp->w_p_scb || wp == curwin)
+	   && (height < wp->w_buffer->b_ml.ml_line_count || wp->w_topline > 1))
+    {
+	/*
+	 * Find a value for w_topline that shows the cursor at the same
+	 * relative position in the window as before (more or less).
+	 */
+	lnum = wp->w_cursor.lnum;
+	if (lnum < 1)		// can happen when starting up
+	    lnum = 1;
+	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L)
+							       / FRACTION_MULT;
+	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
+	sline = wp->w_wrow - line_size;
+
+	if (sline >= 0)
+	{
+	    // Make sure the whole cursor line is visible, if possible.
+	    int rows = plines_win(wp, lnum, FALSE);
+
+	    if (sline > wp->w_height - rows)
+	    {
+		sline = wp->w_height - rows;
+		wp->w_wrow -= rows - line_size;
+	    }
+	}
+
+	if (sline < 0)
+	{
+	    /*
+	     * Cursor line would go off top of screen if w_wrow was this high.
+	     * Make cursor line the first line in the window.  If not enough
+	     * room use w_skipcol;
+	     */
+	    wp->w_wrow = line_size;
+	    if (wp->w_wrow >= wp->w_height
+				       && (wp->w_width - win_col_off(wp)) > 0)
+	    {
+		wp->w_skipcol += wp->w_width - win_col_off(wp);
+		--wp->w_wrow;
+		while (wp->w_wrow >= wp->w_height)
+		{
+		    wp->w_skipcol += wp->w_width - win_col_off(wp)
+							   + win_col_off2(wp);
+		    --wp->w_wrow;
+		}
+	    }
+	}
+	else if (sline > 0)
+	{
+	    while (sline > 0 && lnum > 1)
+	    {
+#ifdef FEAT_FOLDING
+		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
+		if (lnum == 1)
+		{
+		    // first line in buffer is folded
+		    line_size = 1;
+		    --sline;
+		    break;
+		}
+#endif
+		--lnum;
+#ifdef FEAT_DIFF
+		if (lnum == wp->w_topline)
+		    line_size = plines_win_nofill(wp, lnum, TRUE)
+							      + wp->w_topfill;
+		else
+#endif
+		    line_size = plines_win(wp, lnum, TRUE);
+		sline -= line_size;
+	    }
+
+	    if (sline < 0)
+	    {
+		/*
+		 * Line we want at top would go off top of screen.  Use next
+		 * line instead.
+		 */
+#ifdef FEAT_FOLDING
+		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
+#endif
+		lnum++;
+		wp->w_wrow -= line_size + sline;
+	    }
+	    else if (sline > 0)
+	    {
+		// First line of file reached, use that as topline.
+		lnum = 1;
+		wp->w_wrow -= sline;
+	    }
+	}
+	set_topline(wp, lnum);
+    }
+
+    if (wp == curwin)
+	curs_columns(FALSE);	// validate w_wrow
+
+    if (prev_height > 0)
+	wp->w_prev_fraction_row = wp->w_wrow;
+
+    redraw_win_later(wp, UPD_SOME_VALID);
+    invalidate_botline_win(wp);
+}
+
+/*
+ * Set the width of a window.
+ */
+    void
+win_new_width(win_T *wp, int width)
+{
+    // Should we give an error if width < 0?
+    wp->w_width = width < 0 ? 0 : width;
+    wp->w_lines_valid = 0;
+    changed_line_abv_curs_win(wp);
+    invalidate_botline_win(wp);
+
+    if (wp == curwin && *p_spk == 'c')
+	curs_columns(TRUE);	// validate w_wrow
+
+    redraw_win_later(wp, UPD_NOT_VALID);
+    wp->w_redr_status = TRUE;
+}
+
+    void
+win_comp_scroll(win_T *wp)
+{
+#if defined(FEAT_EVAL)
+    int old_w_p_scr = wp->w_p_scr;
+#endif
+
+    wp->w_p_scr = ((unsigned)wp->w_height >> 1);
+    if (wp->w_p_scr == 0)
+	wp->w_p_scr = 1;
+#if defined(FEAT_EVAL)
+    if (wp->w_p_scr != old_w_p_scr)
+    {
+	// Used by "verbose set scroll".
+	wp->w_p_script_ctx[WV_SCROLL].sc_sid = SID_WINLAYOUT;
+	wp->w_p_script_ctx[WV_SCROLL].sc_lnum = 0;
+    }
+#endif
+}
+
+/*
+ * Command_height: called whenever p_ch has been changed.
+ */
+    void
+command_height(void)
+{
+    int		h;
+    frame_T	*frp;
+    int		old_p_ch = curtab->tp_ch_used;
+
+    // Use the value of p_ch that we remembered.  This is needed for when the
+    // GUI starts up, we can't be sure in what order things happen.  And when
+    // p_ch was changed in another tab page.
+    curtab->tp_ch_used = p_ch;
+
+    // If the space for the command line is already more than 'cmdheight' there
+    // is nothing to do (window size must have decreased).
+    if (p_ch > old_p_ch && cmdline_row <= Rows - p_ch)
+	return;
+
+    // Update cmdline_row to what it should be: just below the last window.
+    cmdline_row = topframe->fr_height + tabline_height();
+
+    // If cmdline_row is smaller than what it is supposed to be for 'cmdheight'
+    // then set old_p_ch to what it would be, so that the windows get resized
+    // properly for the new value.
+    if (cmdline_row < Rows - p_ch)
+	old_p_ch = Rows - cmdline_row;
+
+    // Find bottom frame with width of screen.
+    frp = lastwin->w_frame;
+    while (frp->fr_width != Columns && frp->fr_parent != NULL)
+	frp = frp->fr_parent;
+
+    // Avoid changing the height of a window with 'winfixheight' set.
+    while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
+						      && frp->fr_win->w_p_wfh)
+	frp = frp->fr_prev;
+
+    if (starting != NO_SCREEN)
+    {
+	cmdline_row = Rows - p_ch;
+
+	if (p_ch > old_p_ch)		    // p_ch got bigger
+	{
+	    while (p_ch > old_p_ch)
+	    {
+		if (frp == NULL)
+		{
+		    emsg(_(e_not_enough_room));
+		    p_ch = old_p_ch;
+		    curtab->tp_ch_used = p_ch;
+		    cmdline_row = Rows - p_ch;
+		    break;
+		}
+		h = frp->fr_height - frame_minheight(frp, NULL);
+		if (h > p_ch - old_p_ch)
+		    h = p_ch - old_p_ch;
+		old_p_ch += h;
+		frame_add_height(frp, -h);
+		frp = frp->fr_prev;
+	    }
+
+	    // Recompute window positions.
+	    (void)win_comp_pos();
+
+	    // clear the lines added to cmdline
+	    if (full_screen)
+		screen_fill(cmdline_row, (int)Rows, 0,
+						   (int)Columns, ' ', ' ', 0);
+	    msg_row = cmdline_row;
+	    redraw_cmdline = TRUE;
+	    return;
+	}
+
+	if (msg_row < cmdline_row)
+	    msg_row = cmdline_row;
+	redraw_cmdline = TRUE;
+    }
+    frame_add_height(frp, (int)(old_p_ch - p_ch));
+
+    // Recompute window positions.
+    if (frp != lastwin->w_frame)
+	(void)win_comp_pos();
+}
+
+/*
+ * Resize frame "frp" to be "n" lines higher (negative for less high).
+ * Also resize the frames it is contained in.
+ */
+    static void
+frame_add_height(frame_T *frp, int n)
+{
+    frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
+    for (;;)
+    {
+	frp = frp->fr_parent;
+	if (frp == NULL)
+	    break;
+	frp->fr_height += n;
+    }
+}
+
+/*
+ * Add or remove a status line for the bottom window(s), according to the
+ * value of 'laststatus'.
+ */
+    void
+last_status(
+    int		morewin)	// pretend there are two or more windows
+{
+    // Don't make a difference between horizontal or vertical split.
+    last_status_rec(topframe, last_stl_height(morewin) > 0);
+}
+
+    static void
+last_status_rec(frame_T *fr, int statusline)
+{
+    frame_T	*fp;
+    win_T	*wp;
+
+    if (fr->fr_layout == FR_LEAF)
+    {
+	wp = fr->fr_win;
+	if (wp->w_status_height != 0 && !statusline)
+	{
+	    // remove status line
+	    win_new_height(wp, wp->w_height + 1);
+	    wp->w_status_height = 0;
+	    comp_col();
+	}
+	else if (wp->w_status_height == 0 && statusline)
+	{
+	    // Find a frame to take a line from.
+	    fp = fr;
+	    while (fp->fr_height <= frame_minheight(fp, NULL))
+	    {
+		if (fp == topframe)
+		{
+		    emsg(_(e_not_enough_room));
+		    return;
+		}
+		// In a column of frames: go to frame above.  If already at
+		// the top or in a row of frames: go to parent.
+		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
+		    fp = fp->fr_prev;
+		else
+		    fp = fp->fr_parent;
+	    }
+	    wp->w_status_height = 1;
+	    if (fp != fr)
+	    {
+		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
+		frame_fix_height(wp);
+		(void)win_comp_pos();
+	    }
+	    else
+		win_new_height(wp, wp->w_height - 1);
+	    comp_col();
+	    redraw_all_later(UPD_SOME_VALID);
+	}
+	// Set prev_height when difference is due to 'laststatus'.
+	if (abs(wp->w_height - wp->w_prev_height) == 1)
+	    wp->w_prev_height = wp->w_height;
+    }
+    else if (fr->fr_layout == FR_ROW)
+    {
+	// vertically split windows, set status line for each one
+	FOR_ALL_FRAMES(fp, fr->fr_child)
+	    last_status_rec(fp, statusline);
+    }
+    else
+    {
+	// horizontally split window, set status line for last one
+	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
+	    ;
+	last_status_rec(fp, statusline);
+    }
+}
+
+/*
+ * Return the number of lines used by the tab page line.
+ */
+    int
+tabline_height(void)
+{
+#ifdef FEAT_GUI_TABLINE
+    // When the GUI has the tabline then this always returns zero.
+    if (gui_use_tabline())
+	return 0;
+#endif
+    switch (p_stal)
+    {
+	case 0: return 0;
+	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
+    }
+    return 1;
+}
+
+/*
+ * Return the height of the last window's statusline.
+ */
+    int
+last_stl_height(
+    int		morewin)	// pretend there are two or more windows
+{
+    return (p_ls == 2 || (p_ls == 1 && (morewin || !ONE_WINDOW)))
+		? STATUS_HEIGHT : 0;
+}
+
+/*
+ * Return the minimal number of rows that is needed on the screen to display
+ * the current number of windows.
+ */
+    int
+min_rows(void)
+{
+    int		total;
+    tabpage_T	*tp;
+    int		n;
+
+    if (firstwin == NULL)	// not initialized yet
+	return MIN_LINES;
+
+    total = 0;
+    FOR_ALL_TABPAGES(tp)
+    {
+	n = frame_minheight(tp->tp_topframe, NULL);
+	if (total < n)
+	    total = n;
+    }
+    total += tabline_height();
+    total += 1;		// count the room for the command line
+    return total;
+}
+
+/*
+ * Return TRUE if there is only one window and only one tab page, not
+ * counting a help or preview window, unless it is the current window.
+ * Does not count unlisted windows.
+ */
+    int
+only_one_window(void)
+{
+    int		count = 0;
+    win_T	*wp;
+
+#if defined(FEAT_PROP_POPUP)
+    // If the current window is a popup then there always is another window.
+    if (popup_is_popup(curwin))
+	return FALSE;
+#endif
+
+    // If there is another tab page there always is another window.
+    if (first_tabpage->tp_next != NULL)
+	return FALSE;
+
+    FOR_ALL_WINDOWS(wp)
+	if (wp->w_buffer != NULL
+		&& (!((bt_help(wp->w_buffer) && !bt_help(curbuf))
+# ifdef FEAT_QUICKFIX
+		    || wp->w_p_pvw
+# endif
+	     ) || wp == curwin) && !is_aucmd_win(wp))
+	    ++count;
+    return (count <= 1);
+}
+
+/*
+ * Implementation of check_lnums() and check_lnums_nested().
+ */
+    static void
+check_lnums_both(int do_curwin, int nested)
+{
+    win_T	*wp;
+    tabpage_T	*tp;
+
+    FOR_ALL_TAB_WINDOWS(tp, wp)
+	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
+	{
+	    int need_adjust;
+
+	    if (!nested)
+	    {
+		// save the original cursor position and topline
+		wp->w_save_cursor.w_cursor_save = wp->w_cursor;
+		wp->w_save_cursor.w_topline_save = wp->w_topline;
+	    }
+
+	    need_adjust = wp->w_cursor.lnum > curbuf->b_ml.ml_line_count;
+	    if (need_adjust)
+		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
+	    if (need_adjust || !nested)
+		// save the (corrected) cursor position
+		wp->w_save_cursor.w_cursor_corr = wp->w_cursor;
+
+	    need_adjust = wp->w_topline > curbuf->b_ml.ml_line_count;
+	    if (need_adjust)
+		wp->w_topline = curbuf->b_ml.ml_line_count;
+	    if (need_adjust || !nested)
+		// save the (corrected) topline
+		wp->w_save_cursor.w_topline_corr = wp->w_topline;
+	}
+}
+
+/*
+ * Correct the cursor line number in other windows.  Used after changing the
+ * current buffer, and before applying autocommands.
+ * When "do_curwin" is TRUE, also check current window.
+ */
+    void
+check_lnums(int do_curwin)
+{
+    check_lnums_both(do_curwin, FALSE);
+}
+
+/*
+ * Like check_lnums() but for when check_lnums() was already called.
+ */
+    void
+check_lnums_nested(int do_curwin)
+{
+    check_lnums_both(do_curwin, TRUE);
+}
+
+/*
+ * Reset cursor and topline to its stored values from check_lnums().
+ * check_lnums() must have been called first!
+ */
+    void
+reset_lnums(void)
+{
+    win_T	*wp;
+    tabpage_T	*tp;
+
+    FOR_ALL_TAB_WINDOWS(tp, wp)
+	if (wp->w_buffer == curbuf)
+	{
+	    // Restore the value if the autocommand didn't change it and it was
+	    // set.
+	    // Note: This triggers e.g. on BufReadPre, when the buffer is not yet
+	    //       loaded, so cannot validate the buffer line
+	    if (EQUAL_POS(wp->w_save_cursor.w_cursor_corr, wp->w_cursor)
+				  && wp->w_save_cursor.w_cursor_save.lnum != 0)
+		wp->w_cursor = wp->w_save_cursor.w_cursor_save;
+	    if (wp->w_save_cursor.w_topline_corr == wp->w_topline
+				  && wp->w_save_cursor.w_topline_save != 0)
+		wp->w_topline = wp->w_save_cursor.w_topline_save;
+	   if (wp->w_save_cursor.w_topline_save > wp->w_buffer->b_ml.ml_line_count)
+		wp->w_valid &= ~VALID_TOPLINE;
+	}
+}
+
+/*
+ * A snapshot of the window sizes, to restore them after closing the help
+ * or other window.
+ * Only these fields are used:
+ * fr_layout
+ * fr_width
+ * fr_height
+ * fr_next
+ * fr_child
+ * fr_win (only valid for the old curwin, NULL otherwise)
+ */
+
+/*
+ * Create a snapshot of the current frame sizes.
+ * "idx" is SNAP_HELP_IDX or SNAP_AUCMD_IDX.
+ */
+    void
+make_snapshot(int idx)
+{
+    clear_snapshot(curtab, idx);
+    make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
+}
+
+    static void
+make_snapshot_rec(frame_T *fr, frame_T **frp)
+{
+    *frp = ALLOC_CLEAR_ONE(frame_T);
+    if (*frp == NULL)
+	return;
+    (*frp)->fr_layout = fr->fr_layout;
+    (*frp)->fr_width = fr->fr_width;
+    (*frp)->fr_height = fr->fr_height;
+    if (fr->fr_next != NULL)
+	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
+    if (fr->fr_child != NULL)
+	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
+    if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
+	(*frp)->fr_win = curwin;
+}
+
+/*
+ * Remove any existing snapshot.
+ */
+    static void
+clear_snapshot(tabpage_T *tp, int idx)
+{
+    clear_snapshot_rec(tp->tp_snapshot[idx]);
+    tp->tp_snapshot[idx] = NULL;
+}
+
+    static void
+clear_snapshot_rec(frame_T *fr)
+{
+    if (fr == NULL)
+	return;
+    clear_snapshot_rec(fr->fr_next);
+    clear_snapshot_rec(fr->fr_child);
+    vim_free(fr);
+}
+
+/*
+ * Traverse a snapshot to find the previous curwin.
+ */
+    static win_T *
+get_snapshot_curwin_rec(frame_T *ft)
+{
+    win_T	*wp;
+
+    if (ft->fr_next != NULL)
+    {
+	if ((wp = get_snapshot_curwin_rec(ft->fr_next)) != NULL)
+	    return wp;
+    }
+    if (ft->fr_child != NULL)
+    {
+	if ((wp = get_snapshot_curwin_rec(ft->fr_child)) != NULL)
+	    return wp;
+    }
+
+    return ft->fr_win;
+}
+
+/*
+ * Return the current window stored in the snapshot or NULL.
+ */
+    static win_T *
+get_snapshot_curwin(int idx)
+{
+    if (curtab->tp_snapshot[idx] == NULL)
+	return NULL;
+
+    return get_snapshot_curwin_rec(curtab->tp_snapshot[idx]);
+}
+
+/*
+ * Restore a previously created snapshot, if there is any.
+ * This is only done if the screen size didn't change and the window layout is
+ * still the same.
+ * "idx" is SNAP_HELP_IDX or SNAP_AUCMD_IDX.
+ */
+    void
+restore_snapshot(
+    int		idx,
+    int		close_curwin)	    // closing current window
+{
+    win_T	*wp;
+
+    if (curtab->tp_snapshot[idx] != NULL
+	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
+	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
+	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
+    {
+	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
+	win_comp_pos();
+	if (wp != NULL && close_curwin)
+	    win_goto(wp);
+	redraw_all_later(UPD_NOT_VALID);
+    }
+    clear_snapshot(curtab, idx);
+}
+
+/*
+ * Check if frames "sn" and "fr" have the same layout, same following frames
+ * and same children.  And the window pointer is valid.
+ */
+    static int
+check_snapshot_rec(frame_T *sn, frame_T *fr)
+{
+    if (sn->fr_layout != fr->fr_layout
+	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
+	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
+	    || (sn->fr_next != NULL
+		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
+	    || (sn->fr_child != NULL
+		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL)
+	    || (sn->fr_win != NULL && !win_valid(sn->fr_win)))
+	return FAIL;
+    return OK;
+}
+
+/*
+ * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
+ * following frames and children.
+ * Returns a pointer to the old current window, or NULL.
+ */
+    static win_T *
+restore_snapshot_rec(frame_T *sn, frame_T *fr)
+{
+    win_T	*wp = NULL;
+    win_T	*wp2;
+
+    fr->fr_height = sn->fr_height;
+    fr->fr_width = sn->fr_width;
+    if (fr->fr_layout == FR_LEAF)
+    {
+	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
+	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
+	wp = sn->fr_win;
+    }
+    if (sn->fr_next != NULL)
+    {
+	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
+	if (wp2 != NULL)
+	    wp = wp2;
+    }
+    if (sn->fr_child != NULL)
+    {
+	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
+	if (wp2 != NULL)
+	    wp = wp2;
+    }
+    return wp;
+}
+
+#if defined(FEAT_GUI) || defined(PROTO)
+/*
+ * Return TRUE if there is any vertically split window.
+ */
+    int
+win_hasvertsplit(void)
+{
+    frame_T	*fr;
+
+    if (topframe->fr_layout == FR_ROW)
+	return TRUE;
+
+    if (topframe->fr_layout == FR_COL)
+	FOR_ALL_FRAMES(fr, topframe->fr_child)
+	    if (fr->fr_layout == FR_ROW)
+		return TRUE;
+
+    return FALSE;
+}
+#endif
+
+#if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
+    int
+get_win_number(win_T *wp, win_T *first_win)
+{
+    int		i = 1;
+    win_T	*w;
+
+    for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
+	++i;
+
+    if (w == NULL)
+	return 0;
+    else
+	return i;
+}
+
+    int
+get_tab_number(tabpage_T *tp UNUSED)
+{
+    int		i = 1;
+    tabpage_T	*t;
+
+    for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
+	++i;
+
+    if (t == NULL)
+	return 0;
+    else
+	return i;
+}
+#endif
+
+/*
+ * Return TRUE if "topfrp" and its children are at the right height.
+ */
+    static int
+frame_check_height(frame_T *topfrp, int height)
+{
+    frame_T *frp;
+
+    if (topfrp->fr_height != height)
+	return FALSE;
+
+    if (topfrp->fr_layout == FR_ROW)
+	FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	    if (frp->fr_height != height)
+		return FALSE;
+
+    return TRUE;
+}
+
+/*
+ * Return TRUE if "topfrp" and its children are at the right width.
+ */
+    static int
+frame_check_width(frame_T *topfrp, int width)
+{
+    frame_T *frp;
+
+    if (topfrp->fr_width != width)
+	return FALSE;
+
+    if (topfrp->fr_layout == FR_COL)
+	FOR_ALL_FRAMES(frp, topfrp->fr_child)
+	    if (frp->fr_width != width)
+		return FALSE;
+
+    return TRUE;
+}
+
+#if defined(FEAT_SYN_HL) || defined(PROTO)
+/*
+ * Simple int comparison function for use with qsort()
+ */
+    static int
+int_cmp(const void *a, const void *b)
+{
+    return *(const int *)a - *(const int *)b;
+}
+
+/*
+ * Handle setting 'colorcolumn' or 'textwidth' in window "wp".
+ * Returns error message, NULL if it's OK.
+ */
+    char *
+check_colorcolumn(win_T *wp)
+{
+    char_u	*s;
+    int		col;
+    int		count = 0;
+    int		color_cols[256];
+    int		i;
+    int		j = 0;
+
+    if (wp->w_buffer == NULL)
+	return NULL;  // buffer was closed
+
+    for (s = wp->w_p_cc; *s != NUL && count < 255;)
+    {
+	if (*s == '-' || *s == '+')
+	{
+	    // -N and +N: add to 'textwidth'
+	    col = (*s == '-') ? -1 : 1;
+	    ++s;
+	    if (!VIM_ISDIGIT(*s))
+		return e_invalid_argument;
+	    col = col * getdigits(&s);
+	    if (wp->w_buffer->b_p_tw == 0)
+		goto skip;  // 'textwidth' not set, skip this item
+	    col += wp->w_buffer->b_p_tw;
+	    if (col < 0)
+		goto skip;
+	}
+	else if (VIM_ISDIGIT(*s))
+	    col = getdigits(&s);
+	else
+	    return e_invalid_argument;
+	color_cols[count++] = col - 1;  // 1-based to 0-based
+skip:
+	if (*s == NUL)
+	    break;
+	if (*s != ',')
+	    return e_invalid_argument;
+	if (*++s == NUL)
+	    return e_invalid_argument;  // illegal trailing comma as in "set cc=80,"
+    }
+
+    vim_free(wp->w_p_cc_cols);
+    if (count == 0)
+	wp->w_p_cc_cols = NULL;
+    else
+    {
+	wp->w_p_cc_cols = ALLOC_MULT(int, count + 1);
+	if (wp->w_p_cc_cols != NULL)
+	{
+	    // sort the columns for faster usage on screen redraw inside
+	    // win_line()
+	    qsort(color_cols, count, sizeof(int), int_cmp);
+
+	    for (i = 0; i < count; ++i)
+		// skip duplicates
+		if (j == 0 || wp->w_p_cc_cols[j - 1] != color_cols[i])
+		    wp->w_p_cc_cols[j++] = color_cols[i];
+	    wp->w_p_cc_cols[j] = -1;  // end marker
+	}
+    }
+
+    return NULL;  // no error
+}
+#endif