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-rw-r--r--src/undo.c3592
1 files changed, 3592 insertions, 0 deletions
diff --git a/src/undo.c b/src/undo.c
new file mode 100644
index 0000000..6b6dd47
--- /dev/null
+++ b/src/undo.c
@@ -0,0 +1,3592 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * VIM - Vi IMproved by Bram Moolenaar
+ *
+ * Do ":help uganda" in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * undo.c: multi level undo facility
+ *
+ * The saved lines are stored in a list of lists (one for each buffer):
+ *
+ * b_u_oldhead------------------------------------------------+
+ * |
+ * V
+ * +--------------+ +--------------+ +--------------+
+ * b_u_newhead--->| u_header | | u_header | | u_header |
+ * | uh_next------>| uh_next------>| uh_next---->NULL
+ * NULL<--------uh_prev |<---------uh_prev |<---------uh_prev |
+ * | uh_entry | | uh_entry | | uh_entry |
+ * +--------|-----+ +--------|-----+ +--------|-----+
+ * | | |
+ * V V V
+ * +--------------+ +--------------+ +--------------+
+ * | u_entry | | u_entry | | u_entry |
+ * | ue_next | | ue_next | | ue_next |
+ * +--------|-----+ +--------|-----+ +--------|-----+
+ * | | |
+ * V V V
+ * +--------------+ NULL NULL
+ * | u_entry |
+ * | ue_next |
+ * +--------|-----+
+ * |
+ * V
+ * etc.
+ *
+ * Each u_entry list contains the information for one undo or redo.
+ * curbuf->b_u_curhead points to the header of the last undo (the next redo),
+ * or is NULL if nothing has been undone (end of the branch).
+ *
+ * For keeping alternate undo/redo branches the uh_alt field is used. Thus at
+ * each point in the list a branch may appear for an alternate to redo. The
+ * uh_seq field is numbered sequentially to be able to find a newer or older
+ * branch.
+ *
+ * +---------------+ +---------------+
+ * b_u_oldhead --->| u_header | | u_header |
+ * | uh_alt_next ---->| uh_alt_next ----> NULL
+ * NULL <----- uh_alt_prev |<------ uh_alt_prev |
+ * | uh_prev | | uh_prev |
+ * +-----|---------+ +-----|---------+
+ * | |
+ * V V
+ * +---------------+ +---------------+
+ * | u_header | | u_header |
+ * | uh_alt_next | | uh_alt_next |
+ * b_u_newhead --->| uh_alt_prev | | uh_alt_prev |
+ * | uh_prev | | uh_prev |
+ * +-----|---------+ +-----|---------+
+ * | |
+ * V V
+ * NULL +---------------+ +---------------+
+ * | u_header | | u_header |
+ * | uh_alt_next ---->| uh_alt_next |
+ * | uh_alt_prev |<------ uh_alt_prev |
+ * | uh_prev | | uh_prev |
+ * +-----|---------+ +-----|---------+
+ * | |
+ * etc. etc.
+ *
+ *
+ * All data is allocated and will all be freed when the buffer is unloaded.
+ */
+
+/* Uncomment the next line for including the u_check() function. This warns
+ * for errors in the debug information. */
+/* #define U_DEBUG 1 */
+#define UH_MAGIC 0x18dade /* value for uh_magic when in use */
+#define UE_MAGIC 0xabc123 /* value for ue_magic when in use */
+
+/* Size of buffer used for encryption. */
+#define CRYPT_BUF_SIZE 8192
+
+#include "vim.h"
+
+/* Structure passed around between functions.
+ * Avoids passing cryptstate_T when encryption not available. */
+typedef struct {
+ buf_T *bi_buf;
+ FILE *bi_fp;
+#ifdef FEAT_CRYPT
+ cryptstate_T *bi_state;
+ char_u *bi_buffer; /* CRYPT_BUF_SIZE, NULL when not buffering */
+ size_t bi_used; /* bytes written to/read from bi_buffer */
+ size_t bi_avail; /* bytes available in bi_buffer */
+#endif
+} bufinfo_T;
+
+
+static void u_unch_branch(u_header_T *uhp);
+static u_entry_T *u_get_headentry(void);
+static void u_getbot(void);
+static void u_doit(int count);
+static void u_undoredo(int undo);
+static void u_undo_end(int did_undo, int absolute);
+static void u_add_time(char_u *buf, size_t buflen, time_t tt);
+static void u_freeheader(buf_T *buf, u_header_T *uhp, u_header_T **uhpp);
+static void u_freebranch(buf_T *buf, u_header_T *uhp, u_header_T **uhpp);
+static void u_freeentries(buf_T *buf, u_header_T *uhp, u_header_T **uhpp);
+static void u_freeentry(u_entry_T *, long);
+#ifdef FEAT_PERSISTENT_UNDO
+# ifdef FEAT_CRYPT
+static int undo_flush(bufinfo_T *bi);
+# endif
+static int undo_read(bufinfo_T *bi, char_u *buffer, size_t size);
+static int serialize_uep(bufinfo_T *bi, u_entry_T *uep);
+static u_entry_T *unserialize_uep(bufinfo_T *bi, int *error, char_u *file_name);
+static void serialize_pos(bufinfo_T *bi, pos_T pos);
+static void unserialize_pos(bufinfo_T *bi, pos_T *pos);
+static void serialize_visualinfo(bufinfo_T *bi, visualinfo_T *info);
+static void unserialize_visualinfo(bufinfo_T *bi, visualinfo_T *info);
+#endif
+
+#define U_ALLOC_LINE(size) lalloc((long_u)(size), FALSE)
+
+/* used in undo_end() to report number of added and deleted lines */
+static long u_newcount, u_oldcount;
+
+/*
+ * When 'u' flag included in 'cpoptions', we behave like vi. Need to remember
+ * the action that "u" should do.
+ */
+static int undo_undoes = FALSE;
+
+static int lastmark = 0;
+
+#if defined(U_DEBUG) || defined(PROTO)
+/*
+ * Check the undo structures for being valid. Print a warning when something
+ * looks wrong.
+ */
+static int seen_b_u_curhead;
+static int seen_b_u_newhead;
+static int header_count;
+
+ static void
+u_check_tree(u_header_T *uhp,
+ u_header_T *exp_uh_next,
+ u_header_T *exp_uh_alt_prev)
+{
+ u_entry_T *uep;
+
+ if (uhp == NULL)
+ return;
+ ++header_count;
+ if (uhp == curbuf->b_u_curhead && ++seen_b_u_curhead > 1)
+ {
+ emsg("b_u_curhead found twice (looping?)");
+ return;
+ }
+ if (uhp == curbuf->b_u_newhead && ++seen_b_u_newhead > 1)
+ {
+ emsg("b_u_newhead found twice (looping?)");
+ return;
+ }
+
+ if (uhp->uh_magic != UH_MAGIC)
+ emsg("uh_magic wrong (may be using freed memory)");
+ else
+ {
+ /* Check pointers back are correct. */
+ if (uhp->uh_next.ptr != exp_uh_next)
+ {
+ emsg("uh_next wrong");
+ smsg("expected: 0x%x, actual: 0x%x",
+ exp_uh_next, uhp->uh_next.ptr);
+ }
+ if (uhp->uh_alt_prev.ptr != exp_uh_alt_prev)
+ {
+ emsg("uh_alt_prev wrong");
+ smsg("expected: 0x%x, actual: 0x%x",
+ exp_uh_alt_prev, uhp->uh_alt_prev.ptr);
+ }
+
+ /* Check the undo tree at this header. */
+ for (uep = uhp->uh_entry; uep != NULL; uep = uep->ue_next)
+ {
+ if (uep->ue_magic != UE_MAGIC)
+ {
+ emsg("ue_magic wrong (may be using freed memory)");
+ break;
+ }
+ }
+
+ /* Check the next alt tree. */
+ u_check_tree(uhp->uh_alt_next.ptr, uhp->uh_next.ptr, uhp);
+
+ /* Check the next header in this branch. */
+ u_check_tree(uhp->uh_prev.ptr, uhp, NULL);
+ }
+}
+
+ static void
+u_check(int newhead_may_be_NULL)
+{
+ seen_b_u_newhead = 0;
+ seen_b_u_curhead = 0;
+ header_count = 0;
+
+ u_check_tree(curbuf->b_u_oldhead, NULL, NULL);
+
+ if (seen_b_u_newhead == 0 && curbuf->b_u_oldhead != NULL
+ && !(newhead_may_be_NULL && curbuf->b_u_newhead == NULL))
+ semsg("b_u_newhead invalid: 0x%x", curbuf->b_u_newhead);
+ if (curbuf->b_u_curhead != NULL && seen_b_u_curhead == 0)
+ semsg("b_u_curhead invalid: 0x%x", curbuf->b_u_curhead);
+ if (header_count != curbuf->b_u_numhead)
+ {
+ emsg("b_u_numhead invalid");
+ smsg("expected: %ld, actual: %ld",
+ (long)header_count, (long)curbuf->b_u_numhead);
+ }
+}
+#endif
+
+/*
+ * Save the current line for both the "u" and "U" command.
+ * Careful: may trigger autocommands that reload the buffer.
+ * Returns OK or FAIL.
+ */
+ int
+u_save_cursor(void)
+{
+ return (u_save((linenr_T)(curwin->w_cursor.lnum - 1),
+ (linenr_T)(curwin->w_cursor.lnum + 1)));
+}
+
+/*
+ * Save the lines between "top" and "bot" for both the "u" and "U" command.
+ * "top" may be 0 and bot may be curbuf->b_ml.ml_line_count + 1.
+ * Careful: may trigger autocommands that reload the buffer.
+ * Returns FAIL when lines could not be saved, OK otherwise.
+ */
+ int
+u_save(linenr_T top, linenr_T bot)
+{
+ if (undo_off)
+ return OK;
+
+ if (top >= bot || bot > curbuf->b_ml.ml_line_count + 1)
+ return FAIL; // rely on caller to give an error message
+
+ if (top + 2 == bot)
+ u_saveline((linenr_T)(top + 1));
+
+ return (u_savecommon(top, bot, (linenr_T)0, FALSE));
+}
+
+/*
+ * Save the line "lnum" (used by ":s" and "~" command).
+ * The line is replaced, so the new bottom line is lnum + 1.
+ * Careful: may trigger autocommands that reload the buffer.
+ * Returns FAIL when lines could not be saved, OK otherwise.
+ */
+ int
+u_savesub(linenr_T lnum)
+{
+ if (undo_off)
+ return OK;
+
+ return (u_savecommon(lnum - 1, lnum + 1, lnum + 1, FALSE));
+}
+
+/*
+ * A new line is inserted before line "lnum" (used by :s command).
+ * The line is inserted, so the new bottom line is lnum + 1.
+ * Careful: may trigger autocommands that reload the buffer.
+ * Returns FAIL when lines could not be saved, OK otherwise.
+ */
+ int
+u_inssub(linenr_T lnum)
+{
+ if (undo_off)
+ return OK;
+
+ return (u_savecommon(lnum - 1, lnum, lnum + 1, FALSE));
+}
+
+/*
+ * Save the lines "lnum" - "lnum" + nlines (used by delete command).
+ * The lines are deleted, so the new bottom line is lnum, unless the buffer
+ * becomes empty.
+ * Careful: may trigger autocommands that reload the buffer.
+ * Returns FAIL when lines could not be saved, OK otherwise.
+ */
+ int
+u_savedel(linenr_T lnum, long nlines)
+{
+ if (undo_off)
+ return OK;
+
+ return (u_savecommon(lnum - 1, lnum + nlines,
+ nlines == curbuf->b_ml.ml_line_count ? 2 : lnum, FALSE));
+}
+
+/*
+ * Return TRUE when undo is allowed. Otherwise give an error message and
+ * return FALSE.
+ */
+ int
+undo_allowed(void)
+{
+ /* Don't allow changes when 'modifiable' is off. */
+ if (!curbuf->b_p_ma)
+ {
+ emsg(_(e_modifiable));
+ return FALSE;
+ }
+
+#ifdef HAVE_SANDBOX
+ /* In the sandbox it's not allowed to change the text. */
+ if (sandbox != 0)
+ {
+ emsg(_(e_sandbox));
+ return FALSE;
+ }
+#endif
+
+ /* Don't allow changes in the buffer while editing the cmdline. The
+ * caller of getcmdline() may get confused. */
+ if (textlock != 0)
+ {
+ emsg(_(e_secure));
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/*
+ * Get the undolevle value for the current buffer.
+ */
+ static long
+get_undolevel(void)
+{
+ if (curbuf->b_p_ul == NO_LOCAL_UNDOLEVEL)
+ return p_ul;
+ return curbuf->b_p_ul;
+}
+
+/*
+ * u_save_line(): save an allocated copy of line "lnum" into "ul".
+ * Returns FAIL when out of memory.
+ */
+ static int
+u_save_line(undoline_T *ul, linenr_T lnum)
+{
+ char_u *line = ml_get(lnum);
+
+ if (curbuf->b_ml.ml_line_len == 0)
+ {
+ ul->ul_len = 1;
+ ul->ul_line = vim_strsave((char_u *)"");
+ }
+ else
+ {
+ ul->ul_len = curbuf->b_ml.ml_line_len;
+ ul->ul_line = vim_memsave(line, ul->ul_len);
+ }
+ return ul->ul_line == NULL ? FAIL : OK;
+}
+
+/*
+ * Common code for various ways to save text before a change.
+ * "top" is the line above the first changed line.
+ * "bot" is the line below the last changed line.
+ * "newbot" is the new bottom line. Use zero when not known.
+ * "reload" is TRUE when saving for a buffer reload.
+ * Careful: may trigger autocommands that reload the buffer.
+ * Returns FAIL when lines could not be saved, OK otherwise.
+ */
+ int
+u_savecommon(
+ linenr_T top,
+ linenr_T bot,
+ linenr_T newbot,
+ int reload)
+{
+ linenr_T lnum;
+ long i;
+ u_header_T *uhp;
+ u_header_T *old_curhead;
+ u_entry_T *uep;
+ u_entry_T *prev_uep;
+ long size;
+
+ if (!reload)
+ {
+ /* When making changes is not allowed return FAIL. It's a crude way
+ * to make all change commands fail. */
+ if (!undo_allowed())
+ return FAIL;
+
+#ifdef FEAT_NETBEANS_INTG
+ /*
+ * Netbeans defines areas that cannot be modified. Bail out here when
+ * trying to change text in a guarded area.
+ */
+ if (netbeans_active())
+ {
+ if (netbeans_is_guarded(top, bot))
+ {
+ emsg(_(e_guarded));
+ return FAIL;
+ }
+ if (curbuf->b_p_ro)
+ {
+ emsg(_(e_nbreadonly));
+ return FAIL;
+ }
+ }
+#endif
+#ifdef FEAT_TERMINAL
+ /* A change in a terminal buffer removes the highlighting. */
+ term_change_in_curbuf();
+#endif
+
+ /*
+ * Saving text for undo means we are going to make a change. Give a
+ * warning for a read-only file before making the change, so that the
+ * FileChangedRO event can replace the buffer with a read-write version
+ * (e.g., obtained from a source control system).
+ */
+ change_warning(0);
+ if (bot > curbuf->b_ml.ml_line_count + 1)
+ {
+ /* This happens when the FileChangedRO autocommand changes the
+ * file in a way it becomes shorter. */
+ emsg(_("E881: Line count changed unexpectedly"));
+ return FAIL;
+ }
+ }
+
+#ifdef U_DEBUG
+ u_check(FALSE);
+#endif
+
+ size = bot - top - 1;
+
+ /*
+ * If curbuf->b_u_synced == TRUE make a new header.
+ */
+ if (curbuf->b_u_synced)
+ {
+#ifdef FEAT_JUMPLIST
+ /* Need to create new entry in b_changelist. */
+ curbuf->b_new_change = TRUE;
+#endif
+
+ if (get_undolevel() >= 0)
+ {
+ /*
+ * Make a new header entry. Do this first so that we don't mess
+ * up the undo info when out of memory.
+ */
+ uhp = (u_header_T *)U_ALLOC_LINE(sizeof(u_header_T));
+ if (uhp == NULL)
+ goto nomem;
+#ifdef U_DEBUG
+ uhp->uh_magic = UH_MAGIC;
+#endif
+ }
+ else
+ uhp = NULL;
+
+ /*
+ * If we undid more than we redid, move the entry lists before and
+ * including curbuf->b_u_curhead to an alternate branch.
+ */
+ old_curhead = curbuf->b_u_curhead;
+ if (old_curhead != NULL)
+ {
+ curbuf->b_u_newhead = old_curhead->uh_next.ptr;
+ curbuf->b_u_curhead = NULL;
+ }
+
+ /*
+ * free headers to keep the size right
+ */
+ while (curbuf->b_u_numhead > get_undolevel()
+ && curbuf->b_u_oldhead != NULL)
+ {
+ u_header_T *uhfree = curbuf->b_u_oldhead;
+
+ if (uhfree == old_curhead)
+ /* Can't reconnect the branch, delete all of it. */
+ u_freebranch(curbuf, uhfree, &old_curhead);
+ else if (uhfree->uh_alt_next.ptr == NULL)
+ /* There is no branch, only free one header. */
+ u_freeheader(curbuf, uhfree, &old_curhead);
+ else
+ {
+ /* Free the oldest alternate branch as a whole. */
+ while (uhfree->uh_alt_next.ptr != NULL)
+ uhfree = uhfree->uh_alt_next.ptr;
+ u_freebranch(curbuf, uhfree, &old_curhead);
+ }
+#ifdef U_DEBUG
+ u_check(TRUE);
+#endif
+ }
+
+ if (uhp == NULL) /* no undo at all */
+ {
+ if (old_curhead != NULL)
+ u_freebranch(curbuf, old_curhead, NULL);
+ curbuf->b_u_synced = FALSE;
+ return OK;
+ }
+
+ uhp->uh_prev.ptr = NULL;
+ uhp->uh_next.ptr = curbuf->b_u_newhead;
+ uhp->uh_alt_next.ptr = old_curhead;
+ if (old_curhead != NULL)
+ {
+ uhp->uh_alt_prev.ptr = old_curhead->uh_alt_prev.ptr;
+ if (uhp->uh_alt_prev.ptr != NULL)
+ uhp->uh_alt_prev.ptr->uh_alt_next.ptr = uhp;
+ old_curhead->uh_alt_prev.ptr = uhp;
+ if (curbuf->b_u_oldhead == old_curhead)
+ curbuf->b_u_oldhead = uhp;
+ }
+ else
+ uhp->uh_alt_prev.ptr = NULL;
+ if (curbuf->b_u_newhead != NULL)
+ curbuf->b_u_newhead->uh_prev.ptr = uhp;
+
+ uhp->uh_seq = ++curbuf->b_u_seq_last;
+ curbuf->b_u_seq_cur = uhp->uh_seq;
+ uhp->uh_time = vim_time();
+ uhp->uh_save_nr = 0;
+ curbuf->b_u_time_cur = uhp->uh_time + 1;
+
+ uhp->uh_walk = 0;
+ uhp->uh_entry = NULL;
+ uhp->uh_getbot_entry = NULL;
+ uhp->uh_cursor = curwin->w_cursor; /* save cursor pos. for undo */
+ if (virtual_active() && curwin->w_cursor.coladd > 0)
+ uhp->uh_cursor_vcol = getviscol();
+ else
+ uhp->uh_cursor_vcol = -1;
+
+ /* save changed and buffer empty flag for undo */
+ uhp->uh_flags = (curbuf->b_changed ? UH_CHANGED : 0) +
+ ((curbuf->b_ml.ml_flags & ML_EMPTY) ? UH_EMPTYBUF : 0);
+
+ /* save named marks and Visual marks for undo */
+ mch_memmove(uhp->uh_namedm, curbuf->b_namedm, sizeof(pos_T) * NMARKS);
+ uhp->uh_visual = curbuf->b_visual;
+
+ curbuf->b_u_newhead = uhp;
+ if (curbuf->b_u_oldhead == NULL)
+ curbuf->b_u_oldhead = uhp;
+ ++curbuf->b_u_numhead;
+ }
+ else
+ {
+ if (get_undolevel() < 0) /* no undo at all */
+ return OK;
+
+ /*
+ * When saving a single line, and it has been saved just before, it
+ * doesn't make sense saving it again. Saves a lot of memory when
+ * making lots of changes inside the same line.
+ * This is only possible if the previous change didn't increase or
+ * decrease the number of lines.
+ * Check the ten last changes. More doesn't make sense and takes too
+ * long.
+ */
+ if (size == 1)
+ {
+ uep = u_get_headentry();
+ prev_uep = NULL;
+ for (i = 0; i < 10; ++i)
+ {
+ if (uep == NULL)
+ break;
+
+ /* If lines have been inserted/deleted we give up.
+ * Also when the line was included in a multi-line save. */
+ if ((curbuf->b_u_newhead->uh_getbot_entry != uep
+ ? (uep->ue_top + uep->ue_size + 1
+ != (uep->ue_bot == 0
+ ? curbuf->b_ml.ml_line_count + 1
+ : uep->ue_bot))
+ : uep->ue_lcount != curbuf->b_ml.ml_line_count)
+ || (uep->ue_size > 1
+ && top >= uep->ue_top
+ && top + 2 <= uep->ue_top + uep->ue_size + 1))
+ break;
+
+ /* If it's the same line we can skip saving it again. */
+ if (uep->ue_size == 1 && uep->ue_top == top)
+ {
+ if (i > 0)
+ {
+ /* It's not the last entry: get ue_bot for the last
+ * entry now. Following deleted/inserted lines go to
+ * the re-used entry. */
+ u_getbot();
+ curbuf->b_u_synced = FALSE;
+
+ /* Move the found entry to become the last entry. The
+ * order of undo/redo doesn't matter for the entries
+ * we move it over, since they don't change the line
+ * count and don't include this line. It does matter
+ * for the found entry if the line count is changed by
+ * the executed command. */
+ prev_uep->ue_next = uep->ue_next;
+ uep->ue_next = curbuf->b_u_newhead->uh_entry;
+ curbuf->b_u_newhead->uh_entry = uep;
+ }
+
+ /* The executed command may change the line count. */
+ if (newbot != 0)
+ uep->ue_bot = newbot;
+ else if (bot > curbuf->b_ml.ml_line_count)
+ uep->ue_bot = 0;
+ else
+ {
+ uep->ue_lcount = curbuf->b_ml.ml_line_count;
+ curbuf->b_u_newhead->uh_getbot_entry = uep;
+ }
+ return OK;
+ }
+ prev_uep = uep;
+ uep = uep->ue_next;
+ }
+ }
+
+ /* find line number for ue_bot for previous u_save() */
+ u_getbot();
+ }
+
+#if !defined(UNIX) && !defined(WIN32)
+ /*
+ * With Amiga we can't handle big undo's, because
+ * then u_alloc_line would have to allocate a block larger than 32K
+ */
+ if (size >= 8000)
+ goto nomem;
+#endif
+
+ /*
+ * add lines in front of entry list
+ */
+ uep = (u_entry_T *)U_ALLOC_LINE(sizeof(u_entry_T));
+ if (uep == NULL)
+ goto nomem;
+ vim_memset(uep, 0, sizeof(u_entry_T));
+#ifdef U_DEBUG
+ uep->ue_magic = UE_MAGIC;
+#endif
+
+ uep->ue_size = size;
+ uep->ue_top = top;
+ if (newbot != 0)
+ uep->ue_bot = newbot;
+ /*
+ * Use 0 for ue_bot if bot is below last line.
+ * Otherwise we have to compute ue_bot later.
+ */
+ else if (bot > curbuf->b_ml.ml_line_count)
+ uep->ue_bot = 0;
+ else
+ {
+ uep->ue_lcount = curbuf->b_ml.ml_line_count;
+ curbuf->b_u_newhead->uh_getbot_entry = uep;
+ }
+
+ if (size > 0)
+ {
+ if ((uep->ue_array = (undoline_T *)U_ALLOC_LINE(
+ sizeof(undoline_T) * size)) == NULL)
+ {
+ u_freeentry(uep, 0L);
+ goto nomem;
+ }
+ for (i = 0, lnum = top + 1; i < size; ++i)
+ {
+ fast_breakcheck();
+ if (got_int)
+ {
+ u_freeentry(uep, i);
+ return FAIL;
+ }
+ if (u_save_line(&uep->ue_array[i], lnum++) == FAIL)
+ {
+ u_freeentry(uep, i);
+ goto nomem;
+ }
+ }
+ }
+ else
+ uep->ue_array = NULL;
+ uep->ue_next = curbuf->b_u_newhead->uh_entry;
+ curbuf->b_u_newhead->uh_entry = uep;
+ curbuf->b_u_synced = FALSE;
+ undo_undoes = FALSE;
+
+#ifdef U_DEBUG
+ u_check(FALSE);
+#endif
+ return OK;
+
+nomem:
+ msg_silent = 0; /* must display the prompt */
+ if (ask_yesno((char_u *)_("No undo possible; continue anyway"), TRUE)
+ == 'y')
+ {
+ undo_off = TRUE; /* will be reset when character typed */
+ return OK;
+ }
+ do_outofmem_msg((long_u)0);
+ return FAIL;
+}
+
+#if defined(FEAT_PERSISTENT_UNDO) || defined(PROTO)
+
+# define UF_START_MAGIC "Vim\237UnDo\345" /* magic at start of undofile */
+# define UF_START_MAGIC_LEN 9
+# define UF_HEADER_MAGIC 0x5fd0 /* magic at start of header */
+# define UF_HEADER_END_MAGIC 0xe7aa /* magic after last header */
+# define UF_ENTRY_MAGIC 0xf518 /* magic at start of entry */
+# define UF_ENTRY_END_MAGIC 0x3581 /* magic after last entry */
+# define UF_VERSION 2 /* 2-byte undofile version number */
+# define UF_VERSION_CRYPT 0x8002 /* idem, encrypted */
+
+/* extra fields for header */
+# define UF_LAST_SAVE_NR 1
+
+/* extra fields for uhp */
+# define UHP_SAVE_NR 1
+
+static char_u e_not_open[] = N_("E828: Cannot open undo file for writing: %s");
+
+/*
+ * Compute the hash for the current buffer text into hash[UNDO_HASH_SIZE].
+ */
+ void
+u_compute_hash(char_u *hash)
+{
+ context_sha256_T ctx;
+ linenr_T lnum;
+ char_u *p;
+
+ sha256_start(&ctx);
+ for (lnum = 1; lnum <= curbuf->b_ml.ml_line_count; ++lnum)
+ {
+ p = ml_get(lnum);
+ sha256_update(&ctx, p, (UINT32_T)(STRLEN(p) + 1));
+ }
+ sha256_finish(&ctx, hash);
+}
+
+/*
+ * Return an allocated string of the full path of the target undofile.
+ * When "reading" is TRUE find the file to read, go over all directories in
+ * 'undodir'.
+ * When "reading" is FALSE use the first name where the directory exists.
+ * Returns NULL when there is no place to write or no file to read.
+ */
+ char_u *
+u_get_undo_file_name(char_u *buf_ffname, int reading)
+{
+ char_u *dirp;
+ char_u dir_name[IOSIZE + 1];
+ char_u *munged_name = NULL;
+ char_u *undo_file_name = NULL;
+ int dir_len;
+ char_u *p;
+ stat_T st;
+ char_u *ffname = buf_ffname;
+#ifdef HAVE_READLINK
+ char_u fname_buf[MAXPATHL];
+#endif
+
+ if (ffname == NULL)
+ return NULL;
+
+#ifdef HAVE_READLINK
+ /* Expand symlink in the file name, so that we put the undo file with the
+ * actual file instead of with the symlink. */
+ if (resolve_symlink(ffname, fname_buf) == OK)
+ ffname = fname_buf;
+#endif
+
+ /* Loop over 'undodir'. When reading find the first file that exists.
+ * When not reading use the first directory that exists or ".". */
+ dirp = p_udir;
+ while (*dirp != NUL)
+ {
+ dir_len = copy_option_part(&dirp, dir_name, IOSIZE, ",");
+ if (dir_len == 1 && dir_name[0] == '.')
+ {
+ /* Use same directory as the ffname,
+ * "dir/name" -> "dir/.name.un~" */
+ undo_file_name = vim_strnsave(ffname, (int)(STRLEN(ffname) + 5));
+ if (undo_file_name == NULL)
+ break;
+ p = gettail(undo_file_name);
+#ifdef VMS
+ /* VMS can not handle more than one dot in the filenames
+ * use "dir/name" -> "dir/_un_name" - add _un_
+ * at the beginning to keep the extension */
+ mch_memmove(p + 4, p, STRLEN(p) + 1);
+ mch_memmove(p, "_un_", 4);
+
+#else
+ /* Use same directory as the ffname,
+ * "dir/name" -> "dir/.name.un~" */
+ mch_memmove(p + 1, p, STRLEN(p) + 1);
+ *p = '.';
+ STRCAT(p, ".un~");
+#endif
+ }
+ else
+ {
+ dir_name[dir_len] = NUL;
+ if (mch_isdir(dir_name))
+ {
+ if (munged_name == NULL)
+ {
+ munged_name = vim_strsave(ffname);
+ if (munged_name == NULL)
+ return NULL;
+ for (p = munged_name; *p != NUL; MB_PTR_ADV(p))
+ if (vim_ispathsep(*p))
+ *p = '%';
+ }
+ undo_file_name = concat_fnames(dir_name, munged_name, TRUE);
+ }
+ }
+
+ /* When reading check if the file exists. */
+ if (undo_file_name != NULL && (!reading
+ || mch_stat((char *)undo_file_name, &st) >= 0))
+ break;
+ VIM_CLEAR(undo_file_name);
+ }
+
+ vim_free(munged_name);
+ return undo_file_name;
+}
+
+ static void
+corruption_error(char *mesg, char_u *file_name)
+{
+ semsg(_("E825: Corrupted undo file (%s): %s"), mesg, file_name);
+}
+
+ static void
+u_free_uhp(u_header_T *uhp)
+{
+ u_entry_T *nuep;
+ u_entry_T *uep;
+
+ uep = uhp->uh_entry;
+ while (uep != NULL)
+ {
+ nuep = uep->ue_next;
+ u_freeentry(uep, uep->ue_size);
+ uep = nuep;
+ }
+ vim_free(uhp);
+}
+
+/*
+ * Write a sequence of bytes to the undo file.
+ * Buffers and encrypts as needed.
+ * Returns OK or FAIL.
+ */
+ static int
+undo_write(bufinfo_T *bi, char_u *ptr, size_t len)
+{
+#ifdef FEAT_CRYPT
+ if (bi->bi_buffer != NULL)
+ {
+ size_t len_todo = len;
+ char_u *p = ptr;
+
+ while (bi->bi_used + len_todo >= CRYPT_BUF_SIZE)
+ {
+ size_t n = CRYPT_BUF_SIZE - bi->bi_used;
+
+ mch_memmove(bi->bi_buffer + bi->bi_used, p, n);
+ len_todo -= n;
+ p += n;
+ bi->bi_used = CRYPT_BUF_SIZE;
+ if (undo_flush(bi) == FAIL)
+ return FAIL;
+ }
+ if (len_todo > 0)
+ {
+ mch_memmove(bi->bi_buffer + bi->bi_used, p, len_todo);
+ bi->bi_used += len_todo;
+ }
+ return OK;
+ }
+#endif
+ if (fwrite(ptr, len, (size_t)1, bi->bi_fp) != 1)
+ return FAIL;
+ return OK;
+}
+
+#ifdef FEAT_CRYPT
+ static int
+undo_flush(bufinfo_T *bi)
+{
+ if (bi->bi_buffer != NULL && bi->bi_state != NULL && bi->bi_used > 0)
+ {
+ crypt_encode_inplace(bi->bi_state, bi->bi_buffer, bi->bi_used);
+ if (fwrite(bi->bi_buffer, bi->bi_used, (size_t)1, bi->bi_fp) != 1)
+ return FAIL;
+ bi->bi_used = 0;
+ }
+ return OK;
+}
+#endif
+
+/*
+ * Write "ptr[len]" and crypt the bytes when needed.
+ * Returns OK or FAIL.
+ */
+ static int
+fwrite_crypt(bufinfo_T *bi, char_u *ptr, size_t len)
+{
+#ifdef FEAT_CRYPT
+ char_u *copy;
+ char_u small_buf[100];
+ size_t i;
+
+ if (bi->bi_state != NULL && bi->bi_buffer == NULL)
+ {
+ /* crypting every piece of text separately */
+ if (len < 100)
+ copy = small_buf; /* no malloc()/free() for short strings */
+ else
+ {
+ copy = lalloc(len, FALSE);
+ if (copy == NULL)
+ return 0;
+ }
+ crypt_encode(bi->bi_state, ptr, len, copy);
+ i = fwrite(copy, len, (size_t)1, bi->bi_fp);
+ if (copy != small_buf)
+ vim_free(copy);
+ return i == 1 ? OK : FAIL;
+ }
+#endif
+ return undo_write(bi, ptr, len);
+}
+
+/*
+ * Write a number, MSB first, in "len" bytes.
+ * Must match with undo_read_?c() functions.
+ * Returns OK or FAIL.
+ */
+ static int
+undo_write_bytes(bufinfo_T *bi, long_u nr, int len)
+{
+ char_u buf[8];
+ int i;
+ int bufi = 0;
+
+ for (i = len - 1; i >= 0; --i)
+ buf[bufi++] = (char_u)(nr >> (i * 8));
+ return undo_write(bi, buf, (size_t)len);
+}
+
+/*
+ * Write the pointer to an undo header. Instead of writing the pointer itself
+ * we use the sequence number of the header. This is converted back to
+ * pointers when reading. */
+ static void
+put_header_ptr(bufinfo_T *bi, u_header_T *uhp)
+{
+ undo_write_bytes(bi, (long_u)(uhp != NULL ? uhp->uh_seq : 0), 4);
+}
+
+ static int
+undo_read_4c(bufinfo_T *bi)
+{
+#ifdef FEAT_CRYPT
+ if (bi->bi_buffer != NULL)
+ {
+ char_u buf[4];
+ int n;
+
+ undo_read(bi, buf, (size_t)4);
+ n = ((unsigned)buf[0] << 24) + (buf[1] << 16) + (buf[2] << 8) + buf[3];
+ return n;
+ }
+#endif
+ return get4c(bi->bi_fp);
+}
+
+ static int
+undo_read_2c(bufinfo_T *bi)
+{
+#ifdef FEAT_CRYPT
+ if (bi->bi_buffer != NULL)
+ {
+ char_u buf[2];
+ int n;
+
+ undo_read(bi, buf, (size_t)2);
+ n = (buf[0] << 8) + buf[1];
+ return n;
+ }
+#endif
+ return get2c(bi->bi_fp);
+}
+
+ static int
+undo_read_byte(bufinfo_T *bi)
+{
+#ifdef FEAT_CRYPT
+ if (bi->bi_buffer != NULL)
+ {
+ char_u buf[1];
+
+ undo_read(bi, buf, (size_t)1);
+ return buf[0];
+ }
+#endif
+ return getc(bi->bi_fp);
+}
+
+ static time_t
+undo_read_time(bufinfo_T *bi)
+{
+#ifdef FEAT_CRYPT
+ if (bi->bi_buffer != NULL)
+ {
+ char_u buf[8];
+ time_t n = 0;
+ int i;
+
+ undo_read(bi, buf, (size_t)8);
+ for (i = 0; i < 8; ++i)
+ n = (n << 8) + buf[i];
+ return n;
+ }
+#endif
+ return get8ctime(bi->bi_fp);
+}
+
+/*
+ * Read "buffer[size]" from the undo file.
+ * Return OK or FAIL.
+ */
+ static int
+undo_read(bufinfo_T *bi, char_u *buffer, size_t size)
+{
+ int retval = OK;
+
+#ifdef FEAT_CRYPT
+ if (bi->bi_buffer != NULL)
+ {
+ int size_todo = (int)size;
+ char_u *p = buffer;
+
+ while (size_todo > 0)
+ {
+ size_t n;
+
+ if (bi->bi_used >= bi->bi_avail)
+ {
+ n = fread(bi->bi_buffer, 1, (size_t)CRYPT_BUF_SIZE, bi->bi_fp);
+ if (n == 0)
+ {
+ retval = FAIL;
+ break;
+ }
+ bi->bi_avail = n;
+ bi->bi_used = 0;
+ crypt_decode_inplace(bi->bi_state, bi->bi_buffer, bi->bi_avail);
+ }
+ n = size_todo;
+ if (n > bi->bi_avail - bi->bi_used)
+ n = bi->bi_avail - bi->bi_used;
+ mch_memmove(p, bi->bi_buffer + bi->bi_used, n);
+ bi->bi_used += n;
+ size_todo -= (int)n;
+ p += n;
+ }
+ }
+ else
+#endif
+ if (fread(buffer, (size_t)size, 1, bi->bi_fp) != 1)
+ retval = FAIL;
+
+ if (retval == FAIL)
+ /* Error may be checked for only later. Fill with zeros,
+ * so that the reader won't use garbage. */
+ vim_memset(buffer, 0, size);
+ return retval;
+}
+
+/*
+ * Read a string of length "len" from "bi->bi_fd".
+ * "len" can be zero to allocate an empty line.
+ * Decrypt the bytes if needed.
+ * Append a NUL.
+ * Returns a pointer to allocated memory or NULL for failure.
+ */
+ static char_u *
+read_string_decrypt(bufinfo_T *bi, int len)
+{
+ char_u *ptr = alloc((unsigned)len + 1);
+
+ if (ptr != NULL)
+ {
+ if (len > 0 && undo_read(bi, ptr, len) == FAIL)
+ {
+ vim_free(ptr);
+ return NULL;
+ }
+ // In case there are text properties there already is a NUL, but
+ // checking for that is more expensive than just adding a dummy byte.
+ ptr[len] = NUL;
+#ifdef FEAT_CRYPT
+ if (bi->bi_state != NULL && bi->bi_buffer == NULL)
+ crypt_decode_inplace(bi->bi_state, ptr, len);
+#endif
+ }
+ return ptr;
+}
+
+/*
+ * Writes the (not encrypted) header and initializes encryption if needed.
+ */
+ static int
+serialize_header(bufinfo_T *bi, char_u *hash)
+{
+ long len;
+ buf_T *buf = bi->bi_buf;
+ FILE *fp = bi->bi_fp;
+ char_u time_buf[8];
+
+ /* Start writing, first the magic marker and undo info version. */
+ if (fwrite(UF_START_MAGIC, (size_t)UF_START_MAGIC_LEN, (size_t)1, fp) != 1)
+ return FAIL;
+
+ /* If the buffer is encrypted then all text bytes following will be
+ * encrypted. Numbers and other info is not crypted. */
+#ifdef FEAT_CRYPT
+ if (*buf->b_p_key != NUL)
+ {
+ char_u *header;
+ int header_len;
+
+ undo_write_bytes(bi, (long_u)UF_VERSION_CRYPT, 2);
+ bi->bi_state = crypt_create_for_writing(crypt_get_method_nr(buf),
+ buf->b_p_key, &header, &header_len);
+ if (bi->bi_state == NULL)
+ return FAIL;
+ len = (long)fwrite(header, (size_t)header_len, (size_t)1, fp);
+ vim_free(header);
+ if (len != 1)
+ {
+ crypt_free_state(bi->bi_state);
+ bi->bi_state = NULL;
+ return FAIL;
+ }
+
+ if (crypt_whole_undofile(crypt_get_method_nr(buf)))
+ {
+ bi->bi_buffer = alloc(CRYPT_BUF_SIZE);
+ if (bi->bi_buffer == NULL)
+ {
+ crypt_free_state(bi->bi_state);
+ bi->bi_state = NULL;
+ return FAIL;
+ }
+ bi->bi_used = 0;
+ }
+ }
+ else
+#endif
+ undo_write_bytes(bi, (long_u)UF_VERSION, 2);
+
+
+ /* Write a hash of the buffer text, so that we can verify it is still the
+ * same when reading the buffer text. */
+ if (undo_write(bi, hash, (size_t)UNDO_HASH_SIZE) == FAIL)
+ return FAIL;
+
+ /* buffer-specific data */
+ undo_write_bytes(bi, (long_u)buf->b_ml.ml_line_count, 4);
+ len = buf->b_u_line_ptr.ul_line == NULL
+ ? 0L : (long)STRLEN(buf->b_u_line_ptr.ul_line);
+ undo_write_bytes(bi, (long_u)len, 4);
+ if (len > 0 && fwrite_crypt(bi, buf->b_u_line_ptr.ul_line, (size_t)len)
+ == FAIL)
+ return FAIL;
+ undo_write_bytes(bi, (long_u)buf->b_u_line_lnum, 4);
+ undo_write_bytes(bi, (long_u)buf->b_u_line_colnr, 4);
+
+ /* Undo structures header data */
+ put_header_ptr(bi, buf->b_u_oldhead);
+ put_header_ptr(bi, buf->b_u_newhead);
+ put_header_ptr(bi, buf->b_u_curhead);
+
+ undo_write_bytes(bi, (long_u)buf->b_u_numhead, 4);
+ undo_write_bytes(bi, (long_u)buf->b_u_seq_last, 4);
+ undo_write_bytes(bi, (long_u)buf->b_u_seq_cur, 4);
+ time_to_bytes(buf->b_u_time_cur, time_buf);
+ undo_write(bi, time_buf, 8);
+
+ /* Optional fields. */
+ undo_write_bytes(bi, 4, 1);
+ undo_write_bytes(bi, UF_LAST_SAVE_NR, 1);
+ undo_write_bytes(bi, (long_u)buf->b_u_save_nr_last, 4);
+
+ undo_write_bytes(bi, 0, 1); /* end marker */
+
+ return OK;
+}
+
+ static int
+serialize_uhp(bufinfo_T *bi, u_header_T *uhp)
+{
+ int i;
+ u_entry_T *uep;
+ char_u time_buf[8];
+
+ if (undo_write_bytes(bi, (long_u)UF_HEADER_MAGIC, 2) == FAIL)
+ return FAIL;
+
+ put_header_ptr(bi, uhp->uh_next.ptr);
+ put_header_ptr(bi, uhp->uh_prev.ptr);
+ put_header_ptr(bi, uhp->uh_alt_next.ptr);
+ put_header_ptr(bi, uhp->uh_alt_prev.ptr);
+ undo_write_bytes(bi, uhp->uh_seq, 4);
+ serialize_pos(bi, uhp->uh_cursor);
+ undo_write_bytes(bi, (long_u)uhp->uh_cursor_vcol, 4);
+ undo_write_bytes(bi, (long_u)uhp->uh_flags, 2);
+ /* Assume NMARKS will stay the same. */
+ for (i = 0; i < NMARKS; ++i)
+ serialize_pos(bi, uhp->uh_namedm[i]);
+ serialize_visualinfo(bi, &uhp->uh_visual);
+ time_to_bytes(uhp->uh_time, time_buf);
+ undo_write(bi, time_buf, 8);
+
+ /* Optional fields. */
+ undo_write_bytes(bi, 4, 1);
+ undo_write_bytes(bi, UHP_SAVE_NR, 1);
+ undo_write_bytes(bi, (long_u)uhp->uh_save_nr, 4);
+
+ undo_write_bytes(bi, 0, 1); /* end marker */
+
+ /* Write all the entries. */
+ for (uep = uhp->uh_entry; uep != NULL; uep = uep->ue_next)
+ {
+ undo_write_bytes(bi, (long_u)UF_ENTRY_MAGIC, 2);
+ if (serialize_uep(bi, uep) == FAIL)
+ return FAIL;
+ }
+ undo_write_bytes(bi, (long_u)UF_ENTRY_END_MAGIC, 2);
+ return OK;
+}
+
+ static u_header_T *
+unserialize_uhp(bufinfo_T *bi, char_u *file_name)
+{
+ u_header_T *uhp;
+ int i;
+ u_entry_T *uep, *last_uep;
+ int c;
+ int error;
+
+ uhp = (u_header_T *)U_ALLOC_LINE(sizeof(u_header_T));
+ if (uhp == NULL)
+ return NULL;
+ vim_memset(uhp, 0, sizeof(u_header_T));
+#ifdef U_DEBUG
+ uhp->uh_magic = UH_MAGIC;
+#endif
+ uhp->uh_next.seq = undo_read_4c(bi);
+ uhp->uh_prev.seq = undo_read_4c(bi);
+ uhp->uh_alt_next.seq = undo_read_4c(bi);
+ uhp->uh_alt_prev.seq = undo_read_4c(bi);
+ uhp->uh_seq = undo_read_4c(bi);
+ if (uhp->uh_seq <= 0)
+ {
+ corruption_error("uh_seq", file_name);
+ vim_free(uhp);
+ return NULL;
+ }
+ unserialize_pos(bi, &uhp->uh_cursor);
+ uhp->uh_cursor_vcol = undo_read_4c(bi);
+ uhp->uh_flags = undo_read_2c(bi);
+ for (i = 0; i < NMARKS; ++i)
+ unserialize_pos(bi, &uhp->uh_namedm[i]);
+ unserialize_visualinfo(bi, &uhp->uh_visual);
+ uhp->uh_time = undo_read_time(bi);
+
+ /* Optional fields. */
+ for (;;)
+ {
+ int len = undo_read_byte(bi);
+ int what;
+
+ if (len == 0)
+ break;
+ what = undo_read_byte(bi);
+ switch (what)
+ {
+ case UHP_SAVE_NR:
+ uhp->uh_save_nr = undo_read_4c(bi);
+ break;
+ default:
+ /* field not supported, skip */
+ while (--len >= 0)
+ (void)undo_read_byte(bi);
+ }
+ }
+
+ /* Unserialize the uep list. */
+ last_uep = NULL;
+ while ((c = undo_read_2c(bi)) == UF_ENTRY_MAGIC)
+ {
+ error = FALSE;
+ uep = unserialize_uep(bi, &error, file_name);
+ if (last_uep == NULL)
+ uhp->uh_entry = uep;
+ else
+ last_uep->ue_next = uep;
+ last_uep = uep;
+ if (uep == NULL || error)
+ {
+ u_free_uhp(uhp);
+ return NULL;
+ }
+ }
+ if (c != UF_ENTRY_END_MAGIC)
+ {
+ corruption_error("entry end", file_name);
+ u_free_uhp(uhp);
+ return NULL;
+ }
+
+ return uhp;
+}
+
+/*
+ * Serialize "uep".
+ */
+ static int
+serialize_uep(
+ bufinfo_T *bi,
+ u_entry_T *uep)
+{
+ int i;
+ size_t len;
+
+ undo_write_bytes(bi, (long_u)uep->ue_top, 4);
+ undo_write_bytes(bi, (long_u)uep->ue_bot, 4);
+ undo_write_bytes(bi, (long_u)uep->ue_lcount, 4);
+ undo_write_bytes(bi, (long_u)uep->ue_size, 4);
+ for (i = 0; i < uep->ue_size; ++i)
+ {
+ // Text is written without the text properties, since we cannot restore
+ // the text property types.
+ len = STRLEN(uep->ue_array[i].ul_line);
+ if (undo_write_bytes(bi, (long_u)len, 4) == FAIL)
+ return FAIL;
+ if (len > 0 && fwrite_crypt(bi, uep->ue_array[i].ul_line, len) == FAIL)
+ return FAIL;
+ }
+ return OK;
+}
+
+ static u_entry_T *
+unserialize_uep(bufinfo_T *bi, int *error, char_u *file_name)
+{
+ int i;
+ u_entry_T *uep;
+ undoline_T *array = NULL;
+ char_u *line;
+ int line_len;
+
+ uep = (u_entry_T *)U_ALLOC_LINE(sizeof(u_entry_T));
+ if (uep == NULL)
+ return NULL;
+ vim_memset(uep, 0, sizeof(u_entry_T));
+#ifdef U_DEBUG
+ uep->ue_magic = UE_MAGIC;
+#endif
+ uep->ue_top = undo_read_4c(bi);
+ uep->ue_bot = undo_read_4c(bi);
+ uep->ue_lcount = undo_read_4c(bi);
+ uep->ue_size = undo_read_4c(bi);
+ if (uep->ue_size > 0)
+ {
+ if (uep->ue_size < LONG_MAX / (int)sizeof(char_u *))
+ array = (undoline_T *)U_ALLOC_LINE(sizeof(undoline_T) * uep->ue_size);
+ if (array == NULL)
+ {
+ *error = TRUE;
+ return uep;
+ }
+ vim_memset(array, 0, sizeof(undoline_T) * uep->ue_size);
+ }
+ uep->ue_array = array;
+
+ for (i = 0; i < uep->ue_size; ++i)
+ {
+ line_len = undo_read_4c(bi);
+ if (line_len >= 0)
+ line = read_string_decrypt(bi, line_len);
+ else
+ {
+ line = NULL;
+ corruption_error("line length", file_name);
+ }
+ if (line == NULL)
+ {
+ *error = TRUE;
+ return uep;
+ }
+ array[i].ul_line = line;
+ array[i].ul_len = line_len + 1;
+ }
+ return uep;
+}
+
+/*
+ * Serialize "pos".
+ */
+ static void
+serialize_pos(bufinfo_T *bi, pos_T pos)
+{
+ undo_write_bytes(bi, (long_u)pos.lnum, 4);
+ undo_write_bytes(bi, (long_u)pos.col, 4);
+ undo_write_bytes(bi, (long_u)pos.coladd, 4);
+}
+
+/*
+ * Unserialize the pos_T at the current position.
+ */
+ static void
+unserialize_pos(bufinfo_T *bi, pos_T *pos)
+{
+ pos->lnum = undo_read_4c(bi);
+ if (pos->lnum < 0)
+ pos->lnum = 0;
+ pos->col = undo_read_4c(bi);
+ if (pos->col < 0)
+ pos->col = 0;
+ pos->coladd = undo_read_4c(bi);
+ if (pos->coladd < 0)
+ pos->coladd = 0;
+}
+
+/*
+ * Serialize "info".
+ */
+ static void
+serialize_visualinfo(bufinfo_T *bi, visualinfo_T *info)
+{
+ serialize_pos(bi, info->vi_start);
+ serialize_pos(bi, info->vi_end);
+ undo_write_bytes(bi, (long_u)info->vi_mode, 4);
+ undo_write_bytes(bi, (long_u)info->vi_curswant, 4);
+}
+
+/*
+ * Unserialize the visualinfo_T at the current position.
+ */
+ static void
+unserialize_visualinfo(bufinfo_T *bi, visualinfo_T *info)
+{
+ unserialize_pos(bi, &info->vi_start);
+ unserialize_pos(bi, &info->vi_end);
+ info->vi_mode = undo_read_4c(bi);
+ info->vi_curswant = undo_read_4c(bi);
+}
+
+/*
+ * Write the undo tree in an undo file.
+ * When "name" is not NULL, use it as the name of the undo file.
+ * Otherwise use buf->b_ffname to generate the undo file name.
+ * "buf" must never be null, buf->b_ffname is used to obtain the original file
+ * permissions.
+ * "forceit" is TRUE for ":wundo!", FALSE otherwise.
+ * "hash[UNDO_HASH_SIZE]" must be the hash value of the buffer text.
+ */
+ void
+u_write_undo(
+ char_u *name,
+ int forceit,
+ buf_T *buf,
+ char_u *hash)
+{
+ u_header_T *uhp;
+ char_u *file_name;
+ int mark;
+#ifdef U_DEBUG
+ int headers_written = 0;
+#endif
+ int fd;
+ FILE *fp = NULL;
+ int perm;
+ int write_ok = FALSE;
+#ifdef UNIX
+ int st_old_valid = FALSE;
+ stat_T st_old;
+ stat_T st_new;
+#endif
+ bufinfo_T bi;
+
+ vim_memset(&bi, 0, sizeof(bi));
+
+ if (name == NULL)
+ {
+ file_name = u_get_undo_file_name(buf->b_ffname, FALSE);
+ if (file_name == NULL)
+ {
+ if (p_verbose > 0)
+ {
+ verbose_enter();
+ smsg(
+ _("Cannot write undo file in any directory in 'undodir'"));
+ verbose_leave();
+ }
+ return;
+ }
+ }
+ else
+ file_name = name;
+
+ /*
+ * Decide about the permission to use for the undo file. If the buffer
+ * has a name use the permission of the original file. Otherwise only
+ * allow the user to access the undo file.
+ */
+ perm = 0600;
+ if (buf->b_ffname != NULL)
+ {
+#ifdef UNIX
+ if (mch_stat((char *)buf->b_ffname, &st_old) >= 0)
+ {
+ perm = st_old.st_mode;
+ st_old_valid = TRUE;
+ }
+#else
+ perm = mch_getperm(buf->b_ffname);
+ if (perm < 0)
+ perm = 0600;
+#endif
+ }
+
+ /* strip any s-bit and executable bit */
+ perm = perm & 0666;
+
+ /* If the undo file already exists, verify that it actually is an undo
+ * file, and delete it. */
+ if (mch_getperm(file_name) >= 0)
+ {
+ if (name == NULL || !forceit)
+ {
+ /* Check we can read it and it's an undo file. */
+ fd = mch_open((char *)file_name, O_RDONLY|O_EXTRA, 0);
+ if (fd < 0)
+ {
+ if (name != NULL || p_verbose > 0)
+ {
+ if (name == NULL)
+ verbose_enter();
+ smsg(
+ _("Will not overwrite with undo file, cannot read: %s"),
+ file_name);
+ if (name == NULL)
+ verbose_leave();
+ }
+ goto theend;
+ }
+ else
+ {
+ char_u mbuf[UF_START_MAGIC_LEN];
+ int len;
+
+ len = read_eintr(fd, mbuf, UF_START_MAGIC_LEN);
+ close(fd);
+ if (len < UF_START_MAGIC_LEN
+ || memcmp(mbuf, UF_START_MAGIC, UF_START_MAGIC_LEN) != 0)
+ {
+ if (name != NULL || p_verbose > 0)
+ {
+ if (name == NULL)
+ verbose_enter();
+ smsg(
+ _("Will not overwrite, this is not an undo file: %s"),
+ file_name);
+ if (name == NULL)
+ verbose_leave();
+ }
+ goto theend;
+ }
+ }
+ }
+ mch_remove(file_name);
+ }
+
+ /* If there is no undo information at all, quit here after deleting any
+ * existing undo file. */
+ if (buf->b_u_numhead == 0 && buf->b_u_line_ptr.ul_line == NULL)
+ {
+ if (p_verbose > 0)
+ verb_msg(_("Skipping undo file write, nothing to undo"));
+ goto theend;
+ }
+
+ fd = mch_open((char *)file_name,
+ O_CREAT|O_EXTRA|O_WRONLY|O_EXCL|O_NOFOLLOW, perm);
+ if (fd < 0)
+ {
+ semsg(_(e_not_open), file_name);
+ goto theend;
+ }
+ (void)mch_setperm(file_name, perm);
+ if (p_verbose > 0)
+ {
+ verbose_enter();
+ smsg(_("Writing undo file: %s"), file_name);
+ verbose_leave();
+ }
+
+#ifdef U_DEBUG
+ /* Check there is no problem in undo info before writing. */
+ u_check(FALSE);
+#endif
+
+#ifdef UNIX
+ /*
+ * Try to set the group of the undo file same as the original file. If
+ * this fails, set the protection bits for the group same as the
+ * protection bits for others.
+ */
+ if (st_old_valid
+ && mch_stat((char *)file_name, &st_new) >= 0
+ && st_new.st_gid != st_old.st_gid
+# ifdef HAVE_FCHOWN /* sequent-ptx lacks fchown() */
+ && fchown(fd, (uid_t)-1, st_old.st_gid) != 0
+# endif
+ )
+ mch_setperm(file_name, (perm & 0707) | ((perm & 07) << 3));
+# if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
+ if (buf->b_ffname != NULL)
+ mch_copy_sec(buf->b_ffname, file_name);
+# endif
+#endif
+
+ fp = fdopen(fd, "w");
+ if (fp == NULL)
+ {
+ semsg(_(e_not_open), file_name);
+ close(fd);
+ mch_remove(file_name);
+ goto theend;
+ }
+
+ /* Undo must be synced. */
+ u_sync(TRUE);
+
+ /*
+ * Write the header. Initializes encryption, if enabled.
+ */
+ bi.bi_buf = buf;
+ bi.bi_fp = fp;
+ if (serialize_header(&bi, hash) == FAIL)
+ goto write_error;
+
+ /*
+ * Iteratively serialize UHPs and their UEPs from the top down.
+ */
+ mark = ++lastmark;
+ uhp = buf->b_u_oldhead;
+ while (uhp != NULL)
+ {
+ /* Serialize current UHP if we haven't seen it */
+ if (uhp->uh_walk != mark)
+ {
+ uhp->uh_walk = mark;
+#ifdef U_DEBUG
+ ++headers_written;
+#endif
+ if (serialize_uhp(&bi, uhp) == FAIL)
+ goto write_error;
+ }
+
+ /* Now walk through the tree - algorithm from undo_time(). */
+ if (uhp->uh_prev.ptr != NULL && uhp->uh_prev.ptr->uh_walk != mark)
+ uhp = uhp->uh_prev.ptr;
+ else if (uhp->uh_alt_next.ptr != NULL
+ && uhp->uh_alt_next.ptr->uh_walk != mark)
+ uhp = uhp->uh_alt_next.ptr;
+ else if (uhp->uh_next.ptr != NULL && uhp->uh_alt_prev.ptr == NULL
+ && uhp->uh_next.ptr->uh_walk != mark)
+ uhp = uhp->uh_next.ptr;
+ else if (uhp->uh_alt_prev.ptr != NULL)
+ uhp = uhp->uh_alt_prev.ptr;
+ else
+ uhp = uhp->uh_next.ptr;
+ }
+
+ if (undo_write_bytes(&bi, (long_u)UF_HEADER_END_MAGIC, 2) == OK)
+ write_ok = TRUE;
+#ifdef U_DEBUG
+ if (headers_written != buf->b_u_numhead)
+ {
+ semsg("Written %ld headers, ...", headers_written);
+ semsg("... but numhead is %ld", buf->b_u_numhead);
+ }
+#endif
+
+#ifdef FEAT_CRYPT
+ if (bi.bi_state != NULL && undo_flush(&bi) == FAIL)
+ write_ok = FALSE;
+#endif
+
+write_error:
+ fclose(fp);
+ if (!write_ok)
+ semsg(_("E829: write error in undo file: %s"), file_name);
+
+#if defined(WIN3264)
+ /* Copy file attributes; for systems where this can only be done after
+ * closing the file. */
+ if (buf->b_ffname != NULL)
+ (void)mch_copy_file_attribute(buf->b_ffname, file_name);
+#endif
+#ifdef HAVE_ACL
+ if (buf->b_ffname != NULL)
+ {
+ vim_acl_T acl;
+
+ /* For systems that support ACL: get the ACL from the original file. */
+ acl = mch_get_acl(buf->b_ffname);
+ mch_set_acl(file_name, acl);
+ mch_free_acl(acl);
+ }
+#endif
+
+theend:
+#ifdef FEAT_CRYPT
+ if (bi.bi_state != NULL)
+ crypt_free_state(bi.bi_state);
+ vim_free(bi.bi_buffer);
+#endif
+ if (file_name != name)
+ vim_free(file_name);
+}
+
+/*
+ * Load the undo tree from an undo file.
+ * If "name" is not NULL use it as the undo file name. This also means being
+ * a bit more verbose.
+ * Otherwise use curbuf->b_ffname to generate the undo file name.
+ * "hash[UNDO_HASH_SIZE]" must be the hash value of the buffer text.
+ */
+ void
+u_read_undo(char_u *name, char_u *hash, char_u *orig_name)
+{
+ char_u *file_name;
+ FILE *fp;
+ long version, str_len;
+ undoline_T line_ptr;
+ linenr_T line_lnum;
+ colnr_T line_colnr;
+ linenr_T line_count;
+ long num_head = 0;
+ long old_header_seq, new_header_seq, cur_header_seq;
+ long seq_last, seq_cur;
+ long last_save_nr = 0;
+ short old_idx = -1, new_idx = -1, cur_idx = -1;
+ long num_read_uhps = 0;
+ time_t seq_time;
+ int i, j;
+ int c;
+ u_header_T *uhp;
+ u_header_T **uhp_table = NULL;
+ char_u read_hash[UNDO_HASH_SIZE];
+ char_u magic_buf[UF_START_MAGIC_LEN];
+#ifdef U_DEBUG
+ int *uhp_table_used;
+#endif
+#ifdef UNIX
+ stat_T st_orig;
+ stat_T st_undo;
+#endif
+ bufinfo_T bi;
+
+ vim_memset(&bi, 0, sizeof(bi));
+ line_ptr.ul_len = 0;
+ line_ptr.ul_line = NULL;
+
+ if (name == NULL)
+ {
+ file_name = u_get_undo_file_name(curbuf->b_ffname, TRUE);
+ if (file_name == NULL)
+ return;
+
+#ifdef UNIX
+ /* For safety we only read an undo file if the owner is equal to the
+ * owner of the text file or equal to the current user. */
+ if (mch_stat((char *)orig_name, &st_orig) >= 0
+ && mch_stat((char *)file_name, &st_undo) >= 0
+ && st_orig.st_uid != st_undo.st_uid
+ && st_undo.st_uid != getuid())
+ {
+ if (p_verbose > 0)
+ {
+ verbose_enter();
+ smsg(_("Not reading undo file, owner differs: %s"),
+ file_name);
+ verbose_leave();
+ }
+ return;
+ }
+#endif
+ }
+ else
+ file_name = name;
+
+ if (p_verbose > 0)
+ {
+ verbose_enter();
+ smsg(_("Reading undo file: %s"), file_name);
+ verbose_leave();
+ }
+
+ fp = mch_fopen((char *)file_name, "r");
+ if (fp == NULL)
+ {
+ if (name != NULL || p_verbose > 0)
+ semsg(_("E822: Cannot open undo file for reading: %s"), file_name);
+ goto error;
+ }
+ bi.bi_buf = curbuf;
+ bi.bi_fp = fp;
+
+ /*
+ * Read the undo file header.
+ */
+ if (fread(magic_buf, UF_START_MAGIC_LEN, 1, fp) != 1
+ || memcmp(magic_buf, UF_START_MAGIC, UF_START_MAGIC_LEN) != 0)
+ {
+ semsg(_("E823: Not an undo file: %s"), file_name);
+ goto error;
+ }
+ version = get2c(fp);
+ if (version == UF_VERSION_CRYPT)
+ {
+#ifdef FEAT_CRYPT
+ if (*curbuf->b_p_key == NUL)
+ {
+ semsg(_("E832: Non-encrypted file has encrypted undo file: %s"),
+ file_name);
+ goto error;
+ }
+ bi.bi_state = crypt_create_from_file(fp, curbuf->b_p_key);
+ if (bi.bi_state == NULL)
+ {
+ semsg(_("E826: Undo file decryption failed: %s"), file_name);
+ goto error;
+ }
+ if (crypt_whole_undofile(bi.bi_state->method_nr))
+ {
+ bi.bi_buffer = alloc(CRYPT_BUF_SIZE);
+ if (bi.bi_buffer == NULL)
+ {
+ crypt_free_state(bi.bi_state);
+ bi.bi_state = NULL;
+ goto error;
+ }
+ bi.bi_avail = 0;
+ bi.bi_used = 0;
+ }
+#else
+ semsg(_("E827: Undo file is encrypted: %s"), file_name);
+ goto error;
+#endif
+ }
+ else if (version != UF_VERSION)
+ {
+ semsg(_("E824: Incompatible undo file: %s"), file_name);
+ goto error;
+ }
+
+ if (undo_read(&bi, read_hash, (size_t)UNDO_HASH_SIZE) == FAIL)
+ {
+ corruption_error("hash", file_name);
+ goto error;
+ }
+ line_count = (linenr_T)undo_read_4c(&bi);
+ if (memcmp(hash, read_hash, UNDO_HASH_SIZE) != 0
+ || line_count != curbuf->b_ml.ml_line_count)
+ {
+ if (p_verbose > 0 || name != NULL)
+ {
+ if (name == NULL)
+ verbose_enter();
+ give_warning((char_u *)
+ _("File contents changed, cannot use undo info"), TRUE);
+ if (name == NULL)
+ verbose_leave();
+ }
+ goto error;
+ }
+
+ /* Read undo data for "U" command. */
+ str_len = undo_read_4c(&bi);
+ if (str_len < 0)
+ goto error;
+ if (str_len > 0)
+ {
+ line_ptr.ul_line = read_string_decrypt(&bi, str_len);
+ line_ptr.ul_len = str_len + 1;
+ }
+ line_lnum = (linenr_T)undo_read_4c(&bi);
+ line_colnr = (colnr_T)undo_read_4c(&bi);
+ if (line_lnum < 0 || line_colnr < 0)
+ {
+ corruption_error("line lnum/col", file_name);
+ goto error;
+ }
+
+ /* Begin general undo data */
+ old_header_seq = undo_read_4c(&bi);
+ new_header_seq = undo_read_4c(&bi);
+ cur_header_seq = undo_read_4c(&bi);
+ num_head = undo_read_4c(&bi);
+ seq_last = undo_read_4c(&bi);
+ seq_cur = undo_read_4c(&bi);
+ seq_time = undo_read_time(&bi);
+
+ /* Optional header fields. */
+ for (;;)
+ {
+ int len = undo_read_byte(&bi);
+ int what;
+
+ if (len == 0 || len == EOF)
+ break;
+ what = undo_read_byte(&bi);
+ switch (what)
+ {
+ case UF_LAST_SAVE_NR:
+ last_save_nr = undo_read_4c(&bi);
+ break;
+ default:
+ /* field not supported, skip */
+ while (--len >= 0)
+ (void)undo_read_byte(&bi);
+ }
+ }
+
+ /* uhp_table will store the freshly created undo headers we allocate
+ * until we insert them into curbuf. The table remains sorted by the
+ * sequence numbers of the headers.
+ * When there are no headers uhp_table is NULL. */
+ if (num_head > 0)
+ {
+ if (num_head < LONG_MAX / (long)sizeof(u_header_T *))
+ uhp_table = (u_header_T **)U_ALLOC_LINE(
+ num_head * sizeof(u_header_T *));
+ if (uhp_table == NULL)
+ goto error;
+ }
+
+ while ((c = undo_read_2c(&bi)) == UF_HEADER_MAGIC)
+ {
+ if (num_read_uhps >= num_head)
+ {
+ corruption_error("num_head too small", file_name);
+ goto error;
+ }
+
+ uhp = unserialize_uhp(&bi, file_name);
+ if (uhp == NULL)
+ goto error;
+ uhp_table[num_read_uhps++] = uhp;
+ }
+
+ if (num_read_uhps != num_head)
+ {
+ corruption_error("num_head", file_name);
+ goto error;
+ }
+ if (c != UF_HEADER_END_MAGIC)
+ {
+ corruption_error("end marker", file_name);
+ goto error;
+ }
+
+#ifdef U_DEBUG
+ uhp_table_used = (int *)alloc_clear(
+ (unsigned)(sizeof(int) * num_head + 1));
+# define SET_FLAG(j) ++uhp_table_used[j]
+#else
+# define SET_FLAG(j)
+#endif
+
+ /* We have put all of the headers into a table. Now we iterate through the
+ * table and swizzle each sequence number we have stored in uh_*_seq into
+ * a pointer corresponding to the header with that sequence number. */
+ for (i = 0; i < num_head; i++)
+ {
+ uhp = uhp_table[i];
+ if (uhp == NULL)
+ continue;
+ for (j = 0; j < num_head; j++)
+ if (uhp_table[j] != NULL && i != j
+ && uhp_table[i]->uh_seq == uhp_table[j]->uh_seq)
+ {
+ corruption_error("duplicate uh_seq", file_name);
+ goto error;
+ }
+ for (j = 0; j < num_head; j++)
+ if (uhp_table[j] != NULL
+ && uhp_table[j]->uh_seq == uhp->uh_next.seq)
+ {
+ uhp->uh_next.ptr = uhp_table[j];
+ SET_FLAG(j);
+ break;
+ }
+ for (j = 0; j < num_head; j++)
+ if (uhp_table[j] != NULL
+ && uhp_table[j]->uh_seq == uhp->uh_prev.seq)
+ {
+ uhp->uh_prev.ptr = uhp_table[j];
+ SET_FLAG(j);
+ break;
+ }
+ for (j = 0; j < num_head; j++)
+ if (uhp_table[j] != NULL
+ && uhp_table[j]->uh_seq == uhp->uh_alt_next.seq)
+ {
+ uhp->uh_alt_next.ptr = uhp_table[j];
+ SET_FLAG(j);
+ break;
+ }
+ for (j = 0; j < num_head; j++)
+ if (uhp_table[j] != NULL
+ && uhp_table[j]->uh_seq == uhp->uh_alt_prev.seq)
+ {
+ uhp->uh_alt_prev.ptr = uhp_table[j];
+ SET_FLAG(j);
+ break;
+ }
+ if (old_header_seq > 0 && old_idx < 0 && uhp->uh_seq == old_header_seq)
+ {
+ old_idx = i;
+ SET_FLAG(i);
+ }
+ if (new_header_seq > 0 && new_idx < 0 && uhp->uh_seq == new_header_seq)
+ {
+ new_idx = i;
+ SET_FLAG(i);
+ }
+ if (cur_header_seq > 0 && cur_idx < 0 && uhp->uh_seq == cur_header_seq)
+ {
+ cur_idx = i;
+ SET_FLAG(i);
+ }
+ }
+
+ /* Now that we have read the undo info successfully, free the current undo
+ * info and use the info from the file. */
+ u_blockfree(curbuf);
+ curbuf->b_u_oldhead = old_idx < 0 ? NULL : uhp_table[old_idx];
+ curbuf->b_u_newhead = new_idx < 0 ? NULL : uhp_table[new_idx];
+ curbuf->b_u_curhead = cur_idx < 0 ? NULL : uhp_table[cur_idx];
+ curbuf->b_u_line_ptr = line_ptr;
+ curbuf->b_u_line_lnum = line_lnum;
+ curbuf->b_u_line_colnr = line_colnr;
+ curbuf->b_u_numhead = num_head;
+ curbuf->b_u_seq_last = seq_last;
+ curbuf->b_u_seq_cur = seq_cur;
+ curbuf->b_u_time_cur = seq_time;
+ curbuf->b_u_save_nr_last = last_save_nr;
+ curbuf->b_u_save_nr_cur = last_save_nr;
+
+ curbuf->b_u_synced = TRUE;
+ vim_free(uhp_table);
+
+#ifdef U_DEBUG
+ for (i = 0; i < num_head; ++i)
+ if (uhp_table_used[i] == 0)
+ semsg("uhp_table entry %ld not used, leaking memory", i);
+ vim_free(uhp_table_used);
+ u_check(TRUE);
+#endif
+
+ if (name != NULL)
+ smsg(_("Finished reading undo file %s"), file_name);
+ goto theend;
+
+error:
+ vim_free(line_ptr.ul_line);
+ if (uhp_table != NULL)
+ {
+ for (i = 0; i < num_read_uhps; i++)
+ if (uhp_table[i] != NULL)
+ u_free_uhp(uhp_table[i]);
+ vim_free(uhp_table);
+ }
+
+theend:
+#ifdef FEAT_CRYPT
+ if (bi.bi_state != NULL)
+ crypt_free_state(bi.bi_state);
+ vim_free(bi.bi_buffer);
+#endif
+ if (fp != NULL)
+ fclose(fp);
+ if (file_name != name)
+ vim_free(file_name);
+ return;
+}
+
+#endif /* FEAT_PERSISTENT_UNDO */
+
+
+/*
+ * If 'cpoptions' contains 'u': Undo the previous undo or redo (vi compatible).
+ * If 'cpoptions' does not contain 'u': Always undo.
+ */
+ void
+u_undo(int count)
+{
+ /*
+ * If we get an undo command while executing a macro, we behave like the
+ * original vi. If this happens twice in one macro the result will not
+ * be compatible.
+ */
+ if (curbuf->b_u_synced == FALSE)
+ {
+ u_sync(TRUE);
+ count = 1;
+ }
+
+ if (vim_strchr(p_cpo, CPO_UNDO) == NULL)
+ undo_undoes = TRUE;
+ else
+ undo_undoes = !undo_undoes;
+ u_doit(count);
+}
+
+/*
+ * If 'cpoptions' contains 'u': Repeat the previous undo or redo.
+ * If 'cpoptions' does not contain 'u': Always redo.
+ */
+ void
+u_redo(int count)
+{
+ if (vim_strchr(p_cpo, CPO_UNDO) == NULL)
+ undo_undoes = FALSE;
+ u_doit(count);
+}
+
+/*
+ * Undo or redo, depending on 'undo_undoes', 'count' times.
+ */
+ static void
+u_doit(int startcount)
+{
+ int count = startcount;
+
+ if (!undo_allowed())
+ return;
+
+ u_newcount = 0;
+ u_oldcount = 0;
+ if (curbuf->b_ml.ml_flags & ML_EMPTY)
+ u_oldcount = -1;
+ while (count--)
+ {
+ /* Do the change warning now, so that it triggers FileChangedRO when
+ * needed. This may cause the file to be reloaded, that must happen
+ * before we do anything, because it may change curbuf->b_u_curhead
+ * and more. */
+ change_warning(0);
+
+ if (undo_undoes)
+ {
+ if (curbuf->b_u_curhead == NULL) /* first undo */
+ curbuf->b_u_curhead = curbuf->b_u_newhead;
+ else if (get_undolevel() > 0) /* multi level undo */
+ /* get next undo */
+ curbuf->b_u_curhead = curbuf->b_u_curhead->uh_next.ptr;
+ /* nothing to undo */
+ if (curbuf->b_u_numhead == 0 || curbuf->b_u_curhead == NULL)
+ {
+ /* stick curbuf->b_u_curhead at end */
+ curbuf->b_u_curhead = curbuf->b_u_oldhead;
+ beep_flush();
+ if (count == startcount - 1)
+ {
+ msg(_("Already at oldest change"));
+ return;
+ }
+ break;
+ }
+
+ u_undoredo(TRUE);
+ }
+ else
+ {
+ if (curbuf->b_u_curhead == NULL || get_undolevel() <= 0)
+ {
+ beep_flush(); /* nothing to redo */
+ if (count == startcount - 1)
+ {
+ msg(_("Already at newest change"));
+ return;
+ }
+ break;
+ }
+
+ u_undoredo(FALSE);
+
+ /* Advance for next redo. Set "newhead" when at the end of the
+ * redoable changes. */
+ if (curbuf->b_u_curhead->uh_prev.ptr == NULL)
+ curbuf->b_u_newhead = curbuf->b_u_curhead;
+ curbuf->b_u_curhead = curbuf->b_u_curhead->uh_prev.ptr;
+ }
+ }
+ u_undo_end(undo_undoes, FALSE);
+}
+
+/*
+ * Undo or redo over the timeline.
+ * When "step" is negative go back in time, otherwise goes forward in time.
+ * When "sec" is FALSE make "step" steps, when "sec" is TRUE use "step" as
+ * seconds.
+ * When "file" is TRUE use "step" as a number of file writes.
+ * When "absolute" is TRUE use "step" as the sequence number to jump to.
+ * "sec" must be FALSE then.
+ */
+ void
+undo_time(
+ long step,
+ int sec,
+ int file,
+ int absolute)
+{
+ long target;
+ long closest;
+ long closest_start;
+ long closest_seq = 0;
+ long val;
+ u_header_T *uhp = NULL;
+ u_header_T *last;
+ int mark;
+ int nomark;
+ int round;
+ int dosec = sec;
+ int dofile = file;
+ int above = FALSE;
+ int did_undo = TRUE;
+
+ /* First make sure the current undoable change is synced. */
+ if (curbuf->b_u_synced == FALSE)
+ u_sync(TRUE);
+
+ u_newcount = 0;
+ u_oldcount = 0;
+ if (curbuf->b_ml.ml_flags & ML_EMPTY)
+ u_oldcount = -1;
+
+ /* "target" is the node below which we want to be.
+ * Init "closest" to a value we can't reach. */
+ if (absolute)
+ {
+ target = step;
+ closest = -1;
+ }
+ else
+ {
+ if (dosec)
+ target = (long)(curbuf->b_u_time_cur) + step;
+ else if (dofile)
+ {
+ if (step < 0)
+ {
+ /* Going back to a previous write. If there were changes after
+ * the last write, count that as moving one file-write, so
+ * that ":earlier 1f" undoes all changes since the last save. */
+ uhp = curbuf->b_u_curhead;
+ if (uhp != NULL)
+ uhp = uhp->uh_next.ptr;
+ else
+ uhp = curbuf->b_u_newhead;
+ if (uhp != NULL && uhp->uh_save_nr != 0)
+ /* "uh_save_nr" was set in the last block, that means
+ * there were no changes since the last write */
+ target = curbuf->b_u_save_nr_cur + step;
+ else
+ /* count the changes since the last write as one step */
+ target = curbuf->b_u_save_nr_cur + step + 1;
+ if (target <= 0)
+ /* Go to before first write: before the oldest change. Use
+ * the sequence number for that. */
+ dofile = FALSE;
+ }
+ else
+ {
+ /* Moving forward to a newer write. */
+ target = curbuf->b_u_save_nr_cur + step;
+ if (target > curbuf->b_u_save_nr_last)
+ {
+ /* Go to after last write: after the latest change. Use
+ * the sequence number for that. */
+ target = curbuf->b_u_seq_last + 1;
+ dofile = FALSE;
+ }
+ }
+ }
+ else
+ target = curbuf->b_u_seq_cur + step;
+ if (step < 0)
+ {
+ if (target < 0)
+ target = 0;
+ closest = -1;
+ }
+ else
+ {
+ if (dosec)
+ closest = (long)(vim_time() + 1);
+ else if (dofile)
+ closest = curbuf->b_u_save_nr_last + 2;
+ else
+ closest = curbuf->b_u_seq_last + 2;
+ if (target >= closest)
+ target = closest - 1;
+ }
+ }
+ closest_start = closest;
+ closest_seq = curbuf->b_u_seq_cur;
+
+ /* When "target" is 0; Back to origin. */
+ if (target == 0)
+ {
+ mark = lastmark; /* avoid that GCC complains */
+ goto target_zero;
+ }
+
+ /*
+ * May do this twice:
+ * 1. Search for "target", update "closest" to the best match found.
+ * 2. If "target" not found search for "closest".
+ *
+ * When using the closest time we use the sequence number in the second
+ * round, because there may be several entries with the same time.
+ */
+ for (round = 1; round <= 2; ++round)
+ {
+ /* Find the path from the current state to where we want to go. The
+ * desired state can be anywhere in the undo tree, need to go all over
+ * it. We put "nomark" in uh_walk where we have been without success,
+ * "mark" where it could possibly be. */
+ mark = ++lastmark;
+ nomark = ++lastmark;
+
+ if (curbuf->b_u_curhead == NULL) /* at leaf of the tree */
+ uhp = curbuf->b_u_newhead;
+ else
+ uhp = curbuf->b_u_curhead;
+
+ while (uhp != NULL)
+ {
+ uhp->uh_walk = mark;
+ if (dosec)
+ val = (long)(uhp->uh_time);
+ else if (dofile)
+ val = uhp->uh_save_nr;
+ else
+ val = uhp->uh_seq;
+
+ if (round == 1 && !(dofile && val == 0))
+ {
+ /* Remember the header that is closest to the target.
+ * It must be at least in the right direction (checked with
+ * "b_u_seq_cur"). When the timestamp is equal find the
+ * highest/lowest sequence number. */
+ if ((step < 0 ? uhp->uh_seq <= curbuf->b_u_seq_cur
+ : uhp->uh_seq > curbuf->b_u_seq_cur)
+ && ((dosec && val == closest)
+ ? (step < 0
+ ? uhp->uh_seq < closest_seq
+ : uhp->uh_seq > closest_seq)
+ : closest == closest_start
+ || (val > target
+ ? (closest > target
+ ? val - target <= closest - target
+ : val - target <= target - closest)
+ : (closest > target
+ ? target - val <= closest - target
+ : target - val <= target - closest))))
+ {
+ closest = val;
+ closest_seq = uhp->uh_seq;
+ }
+ }
+
+ /* Quit searching when we found a match. But when searching for a
+ * time we need to continue looking for the best uh_seq. */
+ if (target == val && !dosec)
+ {
+ target = uhp->uh_seq;
+ break;
+ }
+
+ /* go down in the tree if we haven't been there */
+ if (uhp->uh_prev.ptr != NULL && uhp->uh_prev.ptr->uh_walk != nomark
+ && uhp->uh_prev.ptr->uh_walk != mark)
+ uhp = uhp->uh_prev.ptr;
+
+ /* go to alternate branch if we haven't been there */
+ else if (uhp->uh_alt_next.ptr != NULL
+ && uhp->uh_alt_next.ptr->uh_walk != nomark
+ && uhp->uh_alt_next.ptr->uh_walk != mark)
+ uhp = uhp->uh_alt_next.ptr;
+
+ /* go up in the tree if we haven't been there and we are at the
+ * start of alternate branches */
+ else if (uhp->uh_next.ptr != NULL && uhp->uh_alt_prev.ptr == NULL
+ && uhp->uh_next.ptr->uh_walk != nomark
+ && uhp->uh_next.ptr->uh_walk != mark)
+ {
+ /* If still at the start we don't go through this change. */
+ if (uhp == curbuf->b_u_curhead)
+ uhp->uh_walk = nomark;
+ uhp = uhp->uh_next.ptr;
+ }
+
+ else
+ {
+ /* need to backtrack; mark this node as useless */
+ uhp->uh_walk = nomark;
+ if (uhp->uh_alt_prev.ptr != NULL)
+ uhp = uhp->uh_alt_prev.ptr;
+ else
+ uhp = uhp->uh_next.ptr;
+ }
+ }
+
+ if (uhp != NULL) /* found it */
+ break;
+
+ if (absolute)
+ {
+ semsg(_("E830: Undo number %ld not found"), step);
+ return;
+ }
+
+ if (closest == closest_start)
+ {
+ if (step < 0)
+ msg(_("Already at oldest change"));
+ else
+ msg(_("Already at newest change"));
+ return;
+ }
+
+ target = closest_seq;
+ dosec = FALSE;
+ dofile = FALSE;
+ if (step < 0)
+ above = TRUE; /* stop above the header */
+ }
+
+target_zero:
+ /* If we found it: Follow the path to go to where we want to be. */
+ if (uhp != NULL || target == 0)
+ {
+ /*
+ * First go up the tree as much as needed.
+ */
+ while (!got_int)
+ {
+ /* Do the change warning now, for the same reason as above. */
+ change_warning(0);
+
+ uhp = curbuf->b_u_curhead;
+ if (uhp == NULL)
+ uhp = curbuf->b_u_newhead;
+ else
+ uhp = uhp->uh_next.ptr;
+ if (uhp == NULL || (target > 0 && uhp->uh_walk != mark)
+ || (uhp->uh_seq == target && !above))
+ break;
+ curbuf->b_u_curhead = uhp;
+ u_undoredo(TRUE);
+ if (target > 0)
+ uhp->uh_walk = nomark; /* don't go back down here */
+ }
+
+ /* When back to origin, redo is not needed. */
+ if (target > 0)
+ {
+ /*
+ * And now go down the tree (redo), branching off where needed.
+ */
+ while (!got_int)
+ {
+ /* Do the change warning now, for the same reason as above. */
+ change_warning(0);
+
+ uhp = curbuf->b_u_curhead;
+ if (uhp == NULL)
+ break;
+
+ /* Go back to the first branch with a mark. */
+ while (uhp->uh_alt_prev.ptr != NULL
+ && uhp->uh_alt_prev.ptr->uh_walk == mark)
+ uhp = uhp->uh_alt_prev.ptr;
+
+ /* Find the last branch with a mark, that's the one. */
+ last = uhp;
+ while (last->uh_alt_next.ptr != NULL
+ && last->uh_alt_next.ptr->uh_walk == mark)
+ last = last->uh_alt_next.ptr;
+ if (last != uhp)
+ {
+ /* Make the used branch the first entry in the list of
+ * alternatives to make "u" and CTRL-R take this branch. */
+ while (uhp->uh_alt_prev.ptr != NULL)
+ uhp = uhp->uh_alt_prev.ptr;
+ if (last->uh_alt_next.ptr != NULL)
+ last->uh_alt_next.ptr->uh_alt_prev.ptr =
+ last->uh_alt_prev.ptr;
+ last->uh_alt_prev.ptr->uh_alt_next.ptr =
+ last->uh_alt_next.ptr;
+ last->uh_alt_prev.ptr = NULL;
+ last->uh_alt_next.ptr = uhp;
+ uhp->uh_alt_prev.ptr = last;
+
+ if (curbuf->b_u_oldhead == uhp)
+ curbuf->b_u_oldhead = last;
+ uhp = last;
+ if (uhp->uh_next.ptr != NULL)
+ uhp->uh_next.ptr->uh_prev.ptr = uhp;
+ }
+ curbuf->b_u_curhead = uhp;
+
+ if (uhp->uh_walk != mark)
+ break; /* must have reached the target */
+
+ /* Stop when going backwards in time and didn't find the exact
+ * header we were looking for. */
+ if (uhp->uh_seq == target && above)
+ {
+ curbuf->b_u_seq_cur = target - 1;
+ break;
+ }
+
+ u_undoredo(FALSE);
+
+ /* Advance "curhead" to below the header we last used. If it
+ * becomes NULL then we need to set "newhead" to this leaf. */
+ if (uhp->uh_prev.ptr == NULL)
+ curbuf->b_u_newhead = uhp;
+ curbuf->b_u_curhead = uhp->uh_prev.ptr;
+ did_undo = FALSE;
+
+ if (uhp->uh_seq == target) /* found it! */
+ break;
+
+ uhp = uhp->uh_prev.ptr;
+ if (uhp == NULL || uhp->uh_walk != mark)
+ {
+ /* Need to redo more but can't find it... */
+ internal_error("undo_time()");
+ break;
+ }
+ }
+ }
+ }
+ u_undo_end(did_undo, absolute);
+}
+
+/*
+ * u_undoredo: common code for undo and redo
+ *
+ * The lines in the file are replaced by the lines in the entry list at
+ * curbuf->b_u_curhead. The replaced lines in the file are saved in the entry
+ * list for the next undo/redo.
+ *
+ * When "undo" is TRUE we go up in the tree, when FALSE we go down.
+ */
+ static void
+u_undoredo(int undo)
+{
+ undoline_T *newarray = NULL;
+ linenr_T oldsize;
+ linenr_T newsize;
+ linenr_T top, bot;
+ linenr_T lnum;
+ linenr_T newlnum = MAXLNUM;
+ long i;
+ u_entry_T *uep, *nuep;
+ u_entry_T *newlist = NULL;
+ int old_flags;
+ int new_flags;
+ pos_T namedm[NMARKS];
+ visualinfo_T visualinfo;
+ int empty_buffer; /* buffer became empty */
+ u_header_T *curhead = curbuf->b_u_curhead;
+
+ /* Don't want autocommands using the undo structures here, they are
+ * invalid till the end. */
+ block_autocmds();
+
+#ifdef U_DEBUG
+ u_check(FALSE);
+#endif
+ old_flags = curhead->uh_flags;
+ new_flags = (curbuf->b_changed ? UH_CHANGED : 0) +
+ ((curbuf->b_ml.ml_flags & ML_EMPTY) ? UH_EMPTYBUF : 0);
+ setpcmark();
+
+ /*
+ * save marks before undo/redo
+ */
+ mch_memmove(namedm, curbuf->b_namedm, sizeof(pos_T) * NMARKS);
+ visualinfo = curbuf->b_visual;
+ curbuf->b_op_start.lnum = curbuf->b_ml.ml_line_count;
+ curbuf->b_op_start.col = 0;
+ curbuf->b_op_end.lnum = 0;
+ curbuf->b_op_end.col = 0;
+
+ for (uep = curhead->uh_entry; uep != NULL; uep = nuep)
+ {
+ top = uep->ue_top;
+ bot = uep->ue_bot;
+ if (bot == 0)
+ bot = curbuf->b_ml.ml_line_count + 1;
+ if (top > curbuf->b_ml.ml_line_count || top >= bot
+ || bot > curbuf->b_ml.ml_line_count + 1)
+ {
+ unblock_autocmds();
+ iemsg(_("E438: u_undo: line numbers wrong"));
+ changed(); /* don't want UNCHANGED now */
+ return;
+ }
+
+ oldsize = bot - top - 1; /* number of lines before undo */
+ newsize = uep->ue_size; /* number of lines after undo */
+
+ if (top < newlnum)
+ {
+ /* If the saved cursor is somewhere in this undo block, move it to
+ * the remembered position. Makes "gwap" put the cursor back
+ * where it was. */
+ lnum = curhead->uh_cursor.lnum;
+ if (lnum >= top && lnum <= top + newsize + 1)
+ {
+ curwin->w_cursor = curhead->uh_cursor;
+ newlnum = curwin->w_cursor.lnum - 1;
+ }
+ else
+ {
+ /* Use the first line that actually changed. Avoids that
+ * undoing auto-formatting puts the cursor in the previous
+ * line. */
+ for (i = 0; i < newsize && i < oldsize; ++i)
+ {
+ char_u *p = ml_get(top + 1 + i);
+
+ if (curbuf->b_ml.ml_line_len != uep->ue_array[i].ul_len
+ || memcmp(uep->ue_array[i].ul_line, p, curbuf->b_ml.ml_line_len) != 0)
+ break;
+ }
+ if (i == newsize && newlnum == MAXLNUM && uep->ue_next == NULL)
+ {
+ newlnum = top;
+ curwin->w_cursor.lnum = newlnum + 1;
+ }
+ else if (i < newsize)
+ {
+ newlnum = top + i;
+ curwin->w_cursor.lnum = newlnum + 1;
+ }
+ }
+ }
+
+ empty_buffer = FALSE;
+
+ /* delete the lines between top and bot and save them in newarray */
+ if (oldsize > 0)
+ {
+ if ((newarray = (undoline_T *)U_ALLOC_LINE(
+ sizeof(undoline_T) * oldsize)) == NULL)
+ {
+ do_outofmem_msg((long_u)(sizeof(undoline_T) * oldsize));
+ /*
+ * We have messed up the entry list, repair is impossible.
+ * we have to free the rest of the list.
+ */
+ while (uep != NULL)
+ {
+ nuep = uep->ue_next;
+ u_freeentry(uep, uep->ue_size);
+ uep = nuep;
+ }
+ break;
+ }
+ /* delete backwards, it goes faster in most cases */
+ for (lnum = bot - 1, i = oldsize; --i >= 0; --lnum)
+ {
+ /* what can we do when we run out of memory? */
+ if (u_save_line(&newarray[i], lnum) == FAIL)
+ do_outofmem_msg((long_u)0);
+ /* remember we deleted the last line in the buffer, and a
+ * dummy empty line will be inserted */
+ if (curbuf->b_ml.ml_line_count == 1)
+ empty_buffer = TRUE;
+ ml_delete(lnum, FALSE);
+ }
+ }
+ else
+ newarray = NULL;
+
+ /* insert the lines in u_array between top and bot */
+ if (newsize)
+ {
+ for (lnum = top, i = 0; i < newsize; ++i, ++lnum)
+ {
+ // If the file is empty, there is an empty line 1 that we
+ // should get rid of, by replacing it with the new line.
+ if (empty_buffer && lnum == 0)
+ ml_replace_len((linenr_T)1, uep->ue_array[i].ul_line, uep->ue_array[i].ul_len, TRUE, TRUE);
+ else
+ ml_append(lnum, uep->ue_array[i].ul_line, (colnr_T)uep->ue_array[i].ul_len, FALSE);
+ vim_free(uep->ue_array[i].ul_line);
+ }
+ vim_free((char_u *)uep->ue_array);
+ }
+
+ /* adjust marks */
+ if (oldsize != newsize)
+ {
+ mark_adjust(top + 1, top + oldsize, (long)MAXLNUM,
+ (long)newsize - (long)oldsize);
+ if (curbuf->b_op_start.lnum > top + oldsize)
+ curbuf->b_op_start.lnum += newsize - oldsize;
+ if (curbuf->b_op_end.lnum > top + oldsize)
+ curbuf->b_op_end.lnum += newsize - oldsize;
+ }
+
+ changed_lines(top + 1, 0, bot, newsize - oldsize);
+
+ /* set '[ and '] mark */
+ if (top + 1 < curbuf->b_op_start.lnum)
+ curbuf->b_op_start.lnum = top + 1;
+ if (newsize == 0 && top + 1 > curbuf->b_op_end.lnum)
+ curbuf->b_op_end.lnum = top + 1;
+ else if (top + newsize > curbuf->b_op_end.lnum)
+ curbuf->b_op_end.lnum = top + newsize;
+
+ u_newcount += newsize;
+ u_oldcount += oldsize;
+ uep->ue_size = oldsize;
+ uep->ue_array = newarray;
+ uep->ue_bot = top + newsize + 1;
+
+ /*
+ * insert this entry in front of the new entry list
+ */
+ nuep = uep->ue_next;
+ uep->ue_next = newlist;
+ newlist = uep;
+ }
+
+ curhead->uh_entry = newlist;
+ curhead->uh_flags = new_flags;
+ if ((old_flags & UH_EMPTYBUF) && BUFEMPTY())
+ curbuf->b_ml.ml_flags |= ML_EMPTY;
+ if (old_flags & UH_CHANGED)
+ changed();
+ else
+#ifdef FEAT_NETBEANS_INTG
+ /* per netbeans undo rules, keep it as modified */
+ if (!isNetbeansModified(curbuf))
+#endif
+ unchanged(curbuf, FALSE);
+
+ /*
+ * restore marks from before undo/redo
+ */
+ for (i = 0; i < NMARKS; ++i)
+ {
+ if (curhead->uh_namedm[i].lnum != 0)
+ curbuf->b_namedm[i] = curhead->uh_namedm[i];
+ if (namedm[i].lnum != 0)
+ curhead->uh_namedm[i] = namedm[i];
+ else
+ curhead->uh_namedm[i].lnum = 0;
+ }
+ if (curhead->uh_visual.vi_start.lnum != 0)
+ {
+ curbuf->b_visual = curhead->uh_visual;
+ curhead->uh_visual = visualinfo;
+ }
+
+ /*
+ * If the cursor is only off by one line, put it at the same position as
+ * before starting the change (for the "o" command).
+ * Otherwise the cursor should go to the first undone line.
+ */
+ if (curhead->uh_cursor.lnum + 1 == curwin->w_cursor.lnum
+ && curwin->w_cursor.lnum > 1)
+ --curwin->w_cursor.lnum;
+ if (curwin->w_cursor.lnum <= curbuf->b_ml.ml_line_count)
+ {
+ if (curhead->uh_cursor.lnum == curwin->w_cursor.lnum)
+ {
+ curwin->w_cursor.col = curhead->uh_cursor.col;
+ if (virtual_active() && curhead->uh_cursor_vcol >= 0)
+ coladvance((colnr_T)curhead->uh_cursor_vcol);
+ else
+ curwin->w_cursor.coladd = 0;
+ }
+ else
+ beginline(BL_SOL | BL_FIX);
+ }
+ else
+ {
+ /* We get here with the current cursor line being past the end (eg
+ * after adding lines at the end of the file, and then undoing it).
+ * check_cursor() will move the cursor to the last line. Move it to
+ * the first column here. */
+ curwin->w_cursor.col = 0;
+ curwin->w_cursor.coladd = 0;
+ }
+
+ /* Make sure the cursor is on an existing line and column. */
+ check_cursor();
+
+ /* Remember where we are for "g-" and ":earlier 10s". */
+ curbuf->b_u_seq_cur = curhead->uh_seq;
+ if (undo)
+ {
+ /* We are below the previous undo. However, to make ":earlier 1s"
+ * work we compute this as being just above the just undone change. */
+ if (curhead->uh_next.ptr != NULL)
+ curbuf->b_u_seq_cur = curhead->uh_next.ptr->uh_seq;
+ else
+ curbuf->b_u_seq_cur = 0;
+ }
+
+ /* Remember where we are for ":earlier 1f" and ":later 1f". */
+ if (curhead->uh_save_nr != 0)
+ {
+ if (undo)
+ curbuf->b_u_save_nr_cur = curhead->uh_save_nr - 1;
+ else
+ curbuf->b_u_save_nr_cur = curhead->uh_save_nr;
+ }
+
+ /* The timestamp can be the same for multiple changes, just use the one of
+ * the undone/redone change. */
+ curbuf->b_u_time_cur = curhead->uh_time;
+
+ unblock_autocmds();
+#ifdef U_DEBUG
+ u_check(FALSE);
+#endif
+}
+
+/*
+ * If we deleted or added lines, report the number of less/more lines.
+ * Otherwise, report the number of changes (this may be incorrect
+ * in some cases, but it's better than nothing).
+ */
+ static void
+u_undo_end(
+ int did_undo, /* just did an undo */
+ int absolute) /* used ":undo N" */
+{
+ char *msgstr;
+ u_header_T *uhp;
+ char_u msgbuf[80];
+
+#ifdef FEAT_FOLDING
+ if ((fdo_flags & FDO_UNDO) && KeyTyped)
+ foldOpenCursor();
+#endif
+
+ if (global_busy /* no messages now, wait until global is finished */
+ || !messaging()) /* 'lazyredraw' set, don't do messages now */
+ return;
+
+ if (curbuf->b_ml.ml_flags & ML_EMPTY)
+ --u_newcount;
+
+ u_oldcount -= u_newcount;
+ if (u_oldcount == -1)
+ msgstr = N_("more line");
+ else if (u_oldcount < 0)
+ msgstr = N_("more lines");
+ else if (u_oldcount == 1)
+ msgstr = N_("line less");
+ else if (u_oldcount > 1)
+ msgstr = N_("fewer lines");
+ else
+ {
+ u_oldcount = u_newcount;
+ if (u_newcount == 1)
+ msgstr = N_("change");
+ else
+ msgstr = N_("changes");
+ }
+
+ if (curbuf->b_u_curhead != NULL)
+ {
+ /* For ":undo N" we prefer a "after #N" message. */
+ if (absolute && curbuf->b_u_curhead->uh_next.ptr != NULL)
+ {
+ uhp = curbuf->b_u_curhead->uh_next.ptr;
+ did_undo = FALSE;
+ }
+ else if (did_undo)
+ uhp = curbuf->b_u_curhead;
+ else
+ uhp = curbuf->b_u_curhead->uh_next.ptr;
+ }
+ else
+ uhp = curbuf->b_u_newhead;
+
+ if (uhp == NULL)
+ *msgbuf = NUL;
+ else
+ u_add_time(msgbuf, sizeof(msgbuf), uhp->uh_time);
+
+#ifdef FEAT_CONCEAL
+ {
+ win_T *wp;
+
+ FOR_ALL_WINDOWS(wp)
+ {
+ if (wp->w_buffer == curbuf && wp->w_p_cole > 0)
+ redraw_win_later(wp, NOT_VALID);
+ }
+ }
+#endif
+
+ smsg_attr_keep(0, _("%ld %s; %s #%ld %s"),
+ u_oldcount < 0 ? -u_oldcount : u_oldcount,
+ _(msgstr),
+ did_undo ? _("before") : _("after"),
+ uhp == NULL ? 0L : uhp->uh_seq,
+ msgbuf);
+}
+
+/*
+ * u_sync: stop adding to the current entry list
+ */
+ void
+u_sync(
+ int force) /* Also sync when no_u_sync is set. */
+{
+ /* Skip it when already synced or syncing is disabled. */
+ if (curbuf->b_u_synced || (!force && no_u_sync > 0))
+ return;
+#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
+ if (p_imst == IM_ON_THE_SPOT && im_is_preediting())
+ return; /* XIM is busy, don't break an undo sequence */
+#endif
+ if (get_undolevel() < 0)
+ curbuf->b_u_synced = TRUE; /* no entries, nothing to do */
+ else
+ {
+ u_getbot(); /* compute ue_bot of previous u_save */
+ curbuf->b_u_curhead = NULL;
+ }
+}
+
+/*
+ * ":undolist": List the leafs of the undo tree
+ */
+ void
+ex_undolist(exarg_T *eap UNUSED)
+{
+ garray_T ga;
+ u_header_T *uhp;
+ int mark;
+ int nomark;
+ int changes = 1;
+ int i;
+
+ /*
+ * 1: walk the tree to find all leafs, put the info in "ga".
+ * 2: sort the lines
+ * 3: display the list
+ */
+ mark = ++lastmark;
+ nomark = ++lastmark;
+ ga_init2(&ga, (int)sizeof(char *), 20);
+
+ uhp = curbuf->b_u_oldhead;
+ while (uhp != NULL)
+ {
+ if (uhp->uh_prev.ptr == NULL && uhp->uh_walk != nomark
+ && uhp->uh_walk != mark)
+ {
+ if (ga_grow(&ga, 1) == FAIL)
+ break;
+ vim_snprintf((char *)IObuff, IOSIZE, "%6ld %7d ",
+ uhp->uh_seq, changes);
+ u_add_time(IObuff + STRLEN(IObuff), IOSIZE - STRLEN(IObuff),
+ uhp->uh_time);
+ if (uhp->uh_save_nr > 0)
+ {
+ while (STRLEN(IObuff) < 33)
+ STRCAT(IObuff, " ");
+ vim_snprintf_add((char *)IObuff, IOSIZE,
+ " %3ld", uhp->uh_save_nr);
+ }
+ ((char_u **)(ga.ga_data))[ga.ga_len++] = vim_strsave(IObuff);
+ }
+
+ uhp->uh_walk = mark;
+
+ /* go down in the tree if we haven't been there */
+ if (uhp->uh_prev.ptr != NULL && uhp->uh_prev.ptr->uh_walk != nomark
+ && uhp->uh_prev.ptr->uh_walk != mark)
+ {
+ uhp = uhp->uh_prev.ptr;
+ ++changes;
+ }
+
+ /* go to alternate branch if we haven't been there */
+ else if (uhp->uh_alt_next.ptr != NULL
+ && uhp->uh_alt_next.ptr->uh_walk != nomark
+ && uhp->uh_alt_next.ptr->uh_walk != mark)
+ uhp = uhp->uh_alt_next.ptr;
+
+ /* go up in the tree if we haven't been there and we are at the
+ * start of alternate branches */
+ else if (uhp->uh_next.ptr != NULL && uhp->uh_alt_prev.ptr == NULL
+ && uhp->uh_next.ptr->uh_walk != nomark
+ && uhp->uh_next.ptr->uh_walk != mark)
+ {
+ uhp = uhp->uh_next.ptr;
+ --changes;
+ }
+
+ else
+ {
+ /* need to backtrack; mark this node as done */
+ uhp->uh_walk = nomark;
+ if (uhp->uh_alt_prev.ptr != NULL)
+ uhp = uhp->uh_alt_prev.ptr;
+ else
+ {
+ uhp = uhp->uh_next.ptr;
+ --changes;
+ }
+ }
+ }
+
+ if (ga.ga_len == 0)
+ msg(_("Nothing to undo"));
+ else
+ {
+ sort_strings((char_u **)ga.ga_data, ga.ga_len);
+
+ msg_start();
+ msg_puts_attr(_("number changes when saved"),
+ HL_ATTR(HLF_T));
+ for (i = 0; i < ga.ga_len && !got_int; ++i)
+ {
+ msg_putchar('\n');
+ if (got_int)
+ break;
+ msg_puts(((char **)ga.ga_data)[i]);
+ }
+ msg_end();
+
+ ga_clear_strings(&ga);
+ }
+}
+
+/*
+ * Put the timestamp of an undo header in "buf[buflen]" in a nice format.
+ */
+ static void
+u_add_time(char_u *buf, size_t buflen, time_t tt)
+{
+#ifdef HAVE_STRFTIME
+ struct tm *curtime;
+
+ if (vim_time() - tt >= 100)
+ {
+ curtime = localtime(&tt);
+ if (vim_time() - tt < (60L * 60L * 12L))
+ /* within 12 hours */
+ (void)strftime((char *)buf, buflen, "%H:%M:%S", curtime);
+ else
+ /* longer ago */
+ (void)strftime((char *)buf, buflen, "%Y/%m/%d %H:%M:%S", curtime);
+ }
+ else
+#endif
+ {
+ long seconds = (long)(vim_time() - tt);
+
+ vim_snprintf((char *)buf, buflen,
+ NGETTEXT("%ld second ago", "%ld seconds ago", seconds),
+ seconds);
+ }
+}
+
+/*
+ * ":undojoin": continue adding to the last entry list
+ */
+ void
+ex_undojoin(exarg_T *eap UNUSED)
+{
+ if (curbuf->b_u_newhead == NULL)
+ return; /* nothing changed before */
+ if (curbuf->b_u_curhead != NULL)
+ {
+ emsg(_("E790: undojoin is not allowed after undo"));
+ return;
+ }
+ if (!curbuf->b_u_synced)
+ return; /* already unsynced */
+ if (get_undolevel() < 0)
+ return; /* no entries, nothing to do */
+ else
+ /* Append next change to the last entry */
+ curbuf->b_u_synced = FALSE;
+}
+
+/*
+ * Called after writing or reloading the file and setting b_changed to FALSE.
+ * Now an undo means that the buffer is modified.
+ */
+ void
+u_unchanged(buf_T *buf)
+{
+ u_unch_branch(buf->b_u_oldhead);
+ buf->b_did_warn = FALSE;
+}
+
+/*
+ * After reloading a buffer which was saved for 'undoreload': Find the first
+ * line that was changed and set the cursor there.
+ */
+ void
+u_find_first_changed(void)
+{
+ u_header_T *uhp = curbuf->b_u_newhead;
+ u_entry_T *uep;
+ linenr_T lnum;
+
+ if (curbuf->b_u_curhead != NULL || uhp == NULL)
+ return; /* undid something in an autocmd? */
+
+ /* Check that the last undo block was for the whole file. */
+ uep = uhp->uh_entry;
+ if (uep->ue_top != 0 || uep->ue_bot != 0)
+ return;
+
+ for (lnum = 1; lnum < curbuf->b_ml.ml_line_count
+ && lnum <= uep->ue_size; ++lnum)
+ {
+ char_u *p = ml_get_buf(curbuf, lnum, FALSE);
+
+ if (uep->ue_array[lnum - 1].ul_len != curbuf->b_ml.ml_line_len
+ || memcmp(p, uep->ue_array[lnum - 1].ul_line, uep->ue_array[lnum - 1].ul_len) != 0)
+ {
+ CLEAR_POS(&(uhp->uh_cursor));
+ uhp->uh_cursor.lnum = lnum;
+ return;
+ }
+ }
+ if (curbuf->b_ml.ml_line_count != uep->ue_size)
+ {
+ /* lines added or deleted at the end, put the cursor there */
+ CLEAR_POS(&(uhp->uh_cursor));
+ uhp->uh_cursor.lnum = lnum;
+ }
+}
+
+/*
+ * Increase the write count, store it in the last undo header, what would be
+ * used for "u".
+ */
+ void
+u_update_save_nr(buf_T *buf)
+{
+ u_header_T *uhp;
+
+ ++buf->b_u_save_nr_last;
+ buf->b_u_save_nr_cur = buf->b_u_save_nr_last;
+ uhp = buf->b_u_curhead;
+ if (uhp != NULL)
+ uhp = uhp->uh_next.ptr;
+ else
+ uhp = buf->b_u_newhead;
+ if (uhp != NULL)
+ uhp->uh_save_nr = buf->b_u_save_nr_last;
+}
+
+ static void
+u_unch_branch(u_header_T *uhp)
+{
+ u_header_T *uh;
+
+ for (uh = uhp; uh != NULL; uh = uh->uh_prev.ptr)
+ {
+ uh->uh_flags |= UH_CHANGED;
+ if (uh->uh_alt_next.ptr != NULL)
+ u_unch_branch(uh->uh_alt_next.ptr); /* recursive */
+ }
+}
+
+/*
+ * Get pointer to last added entry.
+ * If it's not valid, give an error message and return NULL.
+ */
+ static u_entry_T *
+u_get_headentry(void)
+{
+ if (curbuf->b_u_newhead == NULL || curbuf->b_u_newhead->uh_entry == NULL)
+ {
+ iemsg(_("E439: undo list corrupt"));
+ return NULL;
+ }
+ return curbuf->b_u_newhead->uh_entry;
+}
+
+/*
+ * u_getbot(): compute the line number of the previous u_save
+ * It is called only when b_u_synced is FALSE.
+ */
+ static void
+u_getbot(void)
+{
+ u_entry_T *uep;
+ linenr_T extra;
+
+ uep = u_get_headentry(); /* check for corrupt undo list */
+ if (uep == NULL)
+ return;
+
+ uep = curbuf->b_u_newhead->uh_getbot_entry;
+ if (uep != NULL)
+ {
+ /*
+ * the new ue_bot is computed from the number of lines that has been
+ * inserted (0 - deleted) since calling u_save. This is equal to the
+ * old line count subtracted from the current line count.
+ */
+ extra = curbuf->b_ml.ml_line_count - uep->ue_lcount;
+ uep->ue_bot = uep->ue_top + uep->ue_size + 1 + extra;
+ if (uep->ue_bot < 1 || uep->ue_bot > curbuf->b_ml.ml_line_count)
+ {
+ iemsg(_("E440: undo line missing"));
+ uep->ue_bot = uep->ue_top + 1; /* assume all lines deleted, will
+ * get all the old lines back
+ * without deleting the current
+ * ones */
+ }
+
+ curbuf->b_u_newhead->uh_getbot_entry = NULL;
+ }
+
+ curbuf->b_u_synced = TRUE;
+}
+
+/*
+ * Free one header "uhp" and its entry list and adjust the pointers.
+ */
+ static void
+u_freeheader(
+ buf_T *buf,
+ u_header_T *uhp,
+ u_header_T **uhpp) /* if not NULL reset when freeing this header */
+{
+ u_header_T *uhap;
+
+ /* When there is an alternate redo list free that branch completely,
+ * because we can never go there. */
+ if (uhp->uh_alt_next.ptr != NULL)
+ u_freebranch(buf, uhp->uh_alt_next.ptr, uhpp);
+
+ if (uhp->uh_alt_prev.ptr != NULL)
+ uhp->uh_alt_prev.ptr->uh_alt_next.ptr = NULL;
+
+ /* Update the links in the list to remove the header. */
+ if (uhp->uh_next.ptr == NULL)
+ buf->b_u_oldhead = uhp->uh_prev.ptr;
+ else
+ uhp->uh_next.ptr->uh_prev.ptr = uhp->uh_prev.ptr;
+
+ if (uhp->uh_prev.ptr == NULL)
+ buf->b_u_newhead = uhp->uh_next.ptr;
+ else
+ for (uhap = uhp->uh_prev.ptr; uhap != NULL;
+ uhap = uhap->uh_alt_next.ptr)
+ uhap->uh_next.ptr = uhp->uh_next.ptr;
+
+ u_freeentries(buf, uhp, uhpp);
+}
+
+/*
+ * Free an alternate branch and any following alternate branches.
+ */
+ static void
+u_freebranch(
+ buf_T *buf,
+ u_header_T *uhp,
+ u_header_T **uhpp) /* if not NULL reset when freeing this header */
+{
+ u_header_T *tofree, *next;
+
+ /* If this is the top branch we may need to use u_freeheader() to update
+ * all the pointers. */
+ if (uhp == buf->b_u_oldhead)
+ {
+ while (buf->b_u_oldhead != NULL)
+ u_freeheader(buf, buf->b_u_oldhead, uhpp);
+ return;
+ }
+
+ if (uhp->uh_alt_prev.ptr != NULL)
+ uhp->uh_alt_prev.ptr->uh_alt_next.ptr = NULL;
+
+ next = uhp;
+ while (next != NULL)
+ {
+ tofree = next;
+ if (tofree->uh_alt_next.ptr != NULL)
+ u_freebranch(buf, tofree->uh_alt_next.ptr, uhpp); /* recursive */
+ next = tofree->uh_prev.ptr;
+ u_freeentries(buf, tofree, uhpp);
+ }
+}
+
+/*
+ * Free all the undo entries for one header and the header itself.
+ * This means that "uhp" is invalid when returning.
+ */
+ static void
+u_freeentries(
+ buf_T *buf,
+ u_header_T *uhp,
+ u_header_T **uhpp) /* if not NULL reset when freeing this header */
+{
+ u_entry_T *uep, *nuep;
+
+ /* Check for pointers to the header that become invalid now. */
+ if (buf->b_u_curhead == uhp)
+ buf->b_u_curhead = NULL;
+ if (buf->b_u_newhead == uhp)
+ buf->b_u_newhead = NULL; /* freeing the newest entry */
+ if (uhpp != NULL && uhp == *uhpp)
+ *uhpp = NULL;
+
+ for (uep = uhp->uh_entry; uep != NULL; uep = nuep)
+ {
+ nuep = uep->ue_next;
+ u_freeentry(uep, uep->ue_size);
+ }
+
+#ifdef U_DEBUG
+ uhp->uh_magic = 0;
+#endif
+ vim_free((char_u *)uhp);
+ --buf->b_u_numhead;
+}
+
+/*
+ * free entry 'uep' and 'n' lines in uep->ue_array[]
+ */
+ static void
+u_freeentry(u_entry_T *uep, long n)
+{
+ while (n > 0)
+ vim_free(uep->ue_array[--n].ul_line);
+ vim_free((char_u *)uep->ue_array);
+#ifdef U_DEBUG
+ uep->ue_magic = 0;
+#endif
+ vim_free((char_u *)uep);
+}
+
+/*
+ * invalidate the undo buffer; called when storage has already been released
+ */
+ void
+u_clearall(buf_T *buf)
+{
+ buf->b_u_newhead = buf->b_u_oldhead = buf->b_u_curhead = NULL;
+ buf->b_u_synced = TRUE;
+ buf->b_u_numhead = 0;
+ buf->b_u_line_ptr.ul_line = NULL;
+ buf->b_u_line_ptr.ul_len = 0;
+ buf->b_u_line_lnum = 0;
+}
+
+/*
+ * Save the line "lnum" for the "U" command.
+ */
+ void
+u_saveline(linenr_T lnum)
+{
+ if (lnum == curbuf->b_u_line_lnum) /* line is already saved */
+ return;
+ if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count) /* should never happen */
+ return;
+ u_clearline();
+ curbuf->b_u_line_lnum = lnum;
+ if (curwin->w_cursor.lnum == lnum)
+ curbuf->b_u_line_colnr = curwin->w_cursor.col;
+ else
+ curbuf->b_u_line_colnr = 0;
+ if (u_save_line(&curbuf->b_u_line_ptr, lnum) == FAIL)
+ do_outofmem_msg((long_u)0);
+}
+
+/*
+ * clear the line saved for the "U" command
+ * (this is used externally for crossing a line while in insert mode)
+ */
+ void
+u_clearline(void)
+{
+ if (curbuf->b_u_line_ptr.ul_line != NULL)
+ {
+ VIM_CLEAR(curbuf->b_u_line_ptr.ul_line);
+ curbuf->b_u_line_ptr.ul_len = 0;
+ curbuf->b_u_line_lnum = 0;
+ }
+}
+
+/*
+ * Implementation of the "U" command.
+ * Differentiation from vi: "U" can be undone with the next "U".
+ * We also allow the cursor to be in another line.
+ * Careful: may trigger autocommands that reload the buffer.
+ */
+ void
+u_undoline(void)
+{
+ colnr_T t;
+ undoline_T oldp;
+
+ if (undo_off)
+ return;
+
+ if (curbuf->b_u_line_ptr.ul_line == NULL
+ || curbuf->b_u_line_lnum > curbuf->b_ml.ml_line_count)
+ {
+ beep_flush();
+ return;
+ }
+
+ // first save the line for the 'u' command
+ if (u_savecommon(curbuf->b_u_line_lnum - 1,
+ curbuf->b_u_line_lnum + 1, (linenr_T)0, FALSE) == FAIL)
+ return;
+ if (u_save_line(&oldp, curbuf->b_u_line_lnum) == FAIL)
+ {
+ do_outofmem_msg((long_u)0);
+ return;
+ }
+ ml_replace_len(curbuf->b_u_line_lnum, curbuf->b_u_line_ptr.ul_line, curbuf->b_u_line_ptr.ul_len, TRUE, FALSE);
+ changed_bytes(curbuf->b_u_line_lnum, 0);
+ curbuf->b_u_line_ptr = oldp;
+
+ t = curbuf->b_u_line_colnr;
+ if (curwin->w_cursor.lnum == curbuf->b_u_line_lnum)
+ curbuf->b_u_line_colnr = curwin->w_cursor.col;
+ curwin->w_cursor.col = t;
+ curwin->w_cursor.lnum = curbuf->b_u_line_lnum;
+ check_cursor_col();
+}
+
+/*
+ * Free all allocated memory blocks for the buffer 'buf'.
+ */
+ void
+u_blockfree(buf_T *buf)
+{
+ while (buf->b_u_oldhead != NULL)
+ u_freeheader(buf, buf->b_u_oldhead, NULL);
+ vim_free(buf->b_u_line_ptr.ul_line);
+}
+
+/*
+ * Check if the 'modified' flag is set, or 'ff' has changed (only need to
+ * check the first character, because it can only be "dos", "unix" or "mac").
+ * "nofile" and "scratch" type buffers are considered to always be unchanged.
+ * Also considers a buffer changed when a terminal window contains a running
+ * job.
+ */
+ int
+bufIsChanged(buf_T *buf)
+{
+#ifdef FEAT_TERMINAL
+ if (term_job_running(buf->b_term))
+ return TRUE;
+#endif
+ return bufIsChangedNotTerm(buf);
+}
+
+/*
+ * Like bufIsChanged() but ignoring a terminal window.
+ */
+ int
+bufIsChangedNotTerm(buf_T *buf)
+{
+ // In a "prompt" buffer we do respect 'modified', so that we can control
+ // closing the window by setting or resetting that option.
+ return (!bt_dontwrite(buf) || bt_prompt(buf))
+ && (buf->b_changed || file_ff_differs(buf, TRUE));
+}
+
+ int
+curbufIsChanged(void)
+{
+ return bufIsChanged(curbuf);
+}
+
+#if defined(FEAT_EVAL) || defined(PROTO)
+/*
+ * For undotree(): Append the list of undo blocks at "first_uhp" to "list".
+ * Recursive.
+ */
+ void
+u_eval_tree(u_header_T *first_uhp, list_T *list)
+{
+ u_header_T *uhp = first_uhp;
+ dict_T *dict;
+
+ while (uhp != NULL)
+ {
+ dict = dict_alloc();
+ if (dict == NULL)
+ return;
+ dict_add_number(dict, "seq", uhp->uh_seq);
+ dict_add_number(dict, "time", (long)uhp->uh_time);
+ if (uhp == curbuf->b_u_newhead)
+ dict_add_number(dict, "newhead", 1);
+ if (uhp == curbuf->b_u_curhead)
+ dict_add_number(dict, "curhead", 1);
+ if (uhp->uh_save_nr > 0)
+ dict_add_number(dict, "save", uhp->uh_save_nr);
+
+ if (uhp->uh_alt_next.ptr != NULL)
+ {
+ list_T *alt_list = list_alloc();
+
+ if (alt_list != NULL)
+ {
+ /* Recursive call to add alternate undo tree. */
+ u_eval_tree(uhp->uh_alt_next.ptr, alt_list);
+ dict_add_list(dict, "alt", alt_list);
+ }
+ }
+
+ list_append_dict(list, dict);
+ uhp = uhp->uh_prev.ptr;
+ }
+}
+#endif