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+/* 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.
+ */
+
+/*
+ * diff.c: code for diff'ing two, three or four buffers.
+ *
+ * There are three ways to diff:
+ * - Shell out to an external diff program, using files.
+ * - Use the compiled-in xdiff library.
+ * - Let 'diffexpr' do the work, using files.
+ */
+
+#include "vim.h"
+#include "xdiff/xdiff.h"
+
+#if defined(FEAT_DIFF) || defined(PROTO)
+
+static int diff_busy = FALSE; // using diff structs, don't change them
+static int diff_need_update = FALSE; // ex_diffupdate needs to be called
+
+/* flags obtained from the 'diffopt' option */
+#define DIFF_FILLER 0x001 // display filler lines
+#define DIFF_IBLANK 0x002 // ignore empty lines
+#define DIFF_ICASE 0x004 // ignore case
+#define DIFF_IWHITE 0x008 // ignore change in white space
+#define DIFF_IWHITEALL 0x010 // ignore all white space changes
+#define DIFF_IWHITEEOL 0x020 // ignore change in white space at EOL
+#define DIFF_HORIZONTAL 0x040 // horizontal splits
+#define DIFF_VERTICAL 0x080 // vertical splits
+#define DIFF_HIDDEN_OFF 0x100 // diffoff when hidden
+#define DIFF_INTERNAL 0x200 // use internal xdiff algorithm
+#define ALL_WHITE_DIFF (DIFF_IWHITE | DIFF_IWHITEALL | DIFF_IWHITEEOL)
+static int diff_flags = DIFF_INTERNAL | DIFF_FILLER;
+
+static long diff_algorithm = 0;
+
+#define LBUFLEN 50 /* length of line in diff file */
+
+static int diff_a_works = MAYBE; /* TRUE when "diff -a" works, FALSE when it
+ doesn't work, MAYBE when not checked yet */
+#if defined(MSWIN)
+static int diff_bin_works = MAYBE; /* TRUE when "diff --binary" works, FALSE
+ when it doesn't work, MAYBE when not
+ checked yet */
+#endif
+
+// used for diff input
+typedef struct {
+ char_u *din_fname; // used for external diff
+ mmfile_t din_mmfile; // used for internal diff
+} diffin_T;
+
+// used for diff result
+typedef struct {
+ char_u *dout_fname; // used for external diff
+ garray_T dout_ga; // used for internal diff
+} diffout_T;
+
+// two diff inputs and one result
+typedef struct {
+ diffin_T dio_orig; // original file input
+ diffin_T dio_new; // new file input
+ diffout_T dio_diff; // diff result
+ int dio_internal; // using internal diff
+} diffio_T;
+
+static int diff_buf_idx(buf_T *buf);
+static int diff_buf_idx_tp(buf_T *buf, tabpage_T *tp);
+static void diff_mark_adjust_tp(tabpage_T *tp, int idx, linenr_T line1, linenr_T line2, long amount, long amount_after);
+static void diff_check_unchanged(tabpage_T *tp, diff_T *dp);
+static int diff_check_sanity(tabpage_T *tp, diff_T *dp);
+static void diff_redraw(int dofold);
+static int check_external_diff(diffio_T *diffio);
+static int diff_file(diffio_T *diffio);
+static int diff_equal_entry(diff_T *dp, int idx1, int idx2);
+static int diff_cmp(char_u *s1, char_u *s2);
+#ifdef FEAT_FOLDING
+static void diff_fold_update(diff_T *dp, int skip_idx);
+#endif
+static void diff_read(int idx_orig, int idx_new, diffout_T *fname);
+static void diff_copy_entry(diff_T *dprev, diff_T *dp, int idx_orig, int idx_new);
+static diff_T *diff_alloc_new(tabpage_T *tp, diff_T *dprev, diff_T *dp);
+static int parse_diff_ed(char_u *line, linenr_T *lnum_orig, long *count_orig, linenr_T *lnum_new, long *count_new);
+static int parse_diff_unified(char_u *line, linenr_T *lnum_orig, long *count_orig, linenr_T *lnum_new, long *count_new);
+static int xdiff_out(void *priv, mmbuffer_t *mb, int nbuf);
+
+#ifndef USE_CR
+# define tag_fgets vim_fgets
+#endif
+
+/*
+ * Called when deleting or unloading a buffer: No longer make a diff with it.
+ */
+ void
+diff_buf_delete(buf_T *buf)
+{
+ int i;
+ tabpage_T *tp;
+
+ FOR_ALL_TABPAGES(tp)
+ {
+ i = diff_buf_idx_tp(buf, tp);
+ if (i != DB_COUNT)
+ {
+ tp->tp_diffbuf[i] = NULL;
+ tp->tp_diff_invalid = TRUE;
+ if (tp == curtab)
+ diff_redraw(TRUE);
+ }
+ }
+}
+
+/*
+ * Check if the current buffer should be added to or removed from the list of
+ * diff buffers.
+ */
+ void
+diff_buf_adjust(win_T *win)
+{
+ win_T *wp;
+ int i;
+
+ if (!win->w_p_diff)
+ {
+ /* When there is no window showing a diff for this buffer, remove
+ * it from the diffs. */
+ FOR_ALL_WINDOWS(wp)
+ if (wp->w_buffer == win->w_buffer && wp->w_p_diff)
+ break;
+ if (wp == NULL)
+ {
+ i = diff_buf_idx(win->w_buffer);
+ if (i != DB_COUNT)
+ {
+ curtab->tp_diffbuf[i] = NULL;
+ curtab->tp_diff_invalid = TRUE;
+ diff_redraw(TRUE);
+ }
+ }
+ }
+ else
+ diff_buf_add(win->w_buffer);
+}
+
+/*
+ * Add a buffer to make diffs for.
+ * Call this when a new buffer is being edited in the current window where
+ * 'diff' is set.
+ * Marks the current buffer as being part of the diff and requiring updating.
+ * This must be done before any autocmd, because a command may use info
+ * about the screen contents.
+ */
+ void
+diff_buf_add(buf_T *buf)
+{
+ int i;
+
+ if (diff_buf_idx(buf) != DB_COUNT)
+ return; /* It's already there. */
+
+ for (i = 0; i < DB_COUNT; ++i)
+ if (curtab->tp_diffbuf[i] == NULL)
+ {
+ curtab->tp_diffbuf[i] = buf;
+ curtab->tp_diff_invalid = TRUE;
+ diff_redraw(TRUE);
+ return;
+ }
+
+ semsg(_("E96: Cannot diff more than %d buffers"), DB_COUNT);
+}
+
+/*
+ * Remove all buffers to make diffs for.
+ */
+ static void
+diff_buf_clear(void)
+{
+ int i;
+
+ for (i = 0; i < DB_COUNT; ++i)
+ if (curtab->tp_diffbuf[i] != NULL)
+ {
+ curtab->tp_diffbuf[i] = NULL;
+ curtab->tp_diff_invalid = TRUE;
+ diff_redraw(TRUE);
+ }
+}
+
+/*
+ * Find buffer "buf" in the list of diff buffers for the current tab page.
+ * Return its index or DB_COUNT if not found.
+ */
+ static int
+diff_buf_idx(buf_T *buf)
+{
+ int idx;
+
+ for (idx = 0; idx < DB_COUNT; ++idx)
+ if (curtab->tp_diffbuf[idx] == buf)
+ break;
+ return idx;
+}
+
+/*
+ * Find buffer "buf" in the list of diff buffers for tab page "tp".
+ * Return its index or DB_COUNT if not found.
+ */
+ static int
+diff_buf_idx_tp(buf_T *buf, tabpage_T *tp)
+{
+ int idx;
+
+ for (idx = 0; idx < DB_COUNT; ++idx)
+ if (tp->tp_diffbuf[idx] == buf)
+ break;
+ return idx;
+}
+
+/*
+ * Mark the diff info involving buffer "buf" as invalid, it will be updated
+ * when info is requested.
+ */
+ void
+diff_invalidate(buf_T *buf)
+{
+ tabpage_T *tp;
+ int i;
+
+ FOR_ALL_TABPAGES(tp)
+ {
+ i = diff_buf_idx_tp(buf, tp);
+ if (i != DB_COUNT)
+ {
+ tp->tp_diff_invalid = TRUE;
+ if (tp == curtab)
+ diff_redraw(TRUE);
+ }
+ }
+}
+
+/*
+ * Called by mark_adjust(): update line numbers in "curbuf".
+ */
+ void
+diff_mark_adjust(
+ linenr_T line1,
+ linenr_T line2,
+ long amount,
+ long amount_after)
+{
+ int idx;
+ tabpage_T *tp;
+
+ /* Handle all tab pages that use the current buffer in a diff. */
+ FOR_ALL_TABPAGES(tp)
+ {
+ idx = diff_buf_idx_tp(curbuf, tp);
+ if (idx != DB_COUNT)
+ diff_mark_adjust_tp(tp, idx, line1, line2, amount, amount_after);
+ }
+}
+
+/*
+ * Update line numbers in tab page "tp" for "curbuf" with index "idx".
+ * This attempts to update the changes as much as possible:
+ * When inserting/deleting lines outside of existing change blocks, create a
+ * new change block and update the line numbers in following blocks.
+ * When inserting/deleting lines in existing change blocks, update them.
+ */
+ static void
+diff_mark_adjust_tp(
+ tabpage_T *tp,
+ int idx,
+ linenr_T line1,
+ linenr_T line2,
+ long amount,
+ long amount_after)
+{
+ diff_T *dp;
+ diff_T *dprev;
+ diff_T *dnext;
+ int i;
+ int inserted, deleted;
+ int n, off;
+ linenr_T last;
+ linenr_T lnum_deleted = line1; /* lnum of remaining deletion */
+ int check_unchanged;
+
+ if (diff_internal())
+ {
+ // Will update diffs before redrawing. Set _invalid to update the
+ // diffs themselves, set _update to also update folds properly just
+ // before redrawing.
+ // Do update marks here, it is needed for :%diffput.
+ tp->tp_diff_invalid = TRUE;
+ tp->tp_diff_update = TRUE;
+ }
+
+ if (line2 == MAXLNUM)
+ {
+ /* mark_adjust(99, MAXLNUM, 9, 0): insert lines */
+ inserted = amount;
+ deleted = 0;
+ }
+ else if (amount_after > 0)
+ {
+ /* mark_adjust(99, 98, MAXLNUM, 9): a change that inserts lines*/
+ inserted = amount_after;
+ deleted = 0;
+ }
+ else
+ {
+ /* mark_adjust(98, 99, MAXLNUM, -2): delete lines */
+ inserted = 0;
+ deleted = -amount_after;
+ }
+
+ dprev = NULL;
+ dp = tp->tp_first_diff;
+ for (;;)
+ {
+ /* If the change is after the previous diff block and before the next
+ * diff block, thus not touching an existing change, create a new diff
+ * block. Don't do this when ex_diffgetput() is busy. */
+ if ((dp == NULL || dp->df_lnum[idx] - 1 > line2
+ || (line2 == MAXLNUM && dp->df_lnum[idx] > line1))
+ && (dprev == NULL
+ || dprev->df_lnum[idx] + dprev->df_count[idx] < line1)
+ && !diff_busy)
+ {
+ dnext = diff_alloc_new(tp, dprev, dp);
+ if (dnext == NULL)
+ return;
+
+ dnext->df_lnum[idx] = line1;
+ dnext->df_count[idx] = inserted;
+ for (i = 0; i < DB_COUNT; ++i)
+ if (tp->tp_diffbuf[i] != NULL && i != idx)
+ {
+ if (dprev == NULL)
+ dnext->df_lnum[i] = line1;
+ else
+ dnext->df_lnum[i] = line1
+ + (dprev->df_lnum[i] + dprev->df_count[i])
+ - (dprev->df_lnum[idx] + dprev->df_count[idx]);
+ dnext->df_count[i] = deleted;
+ }
+ }
+
+ /* if at end of the list, quit */
+ if (dp == NULL)
+ break;
+
+ /*
+ * Check for these situations:
+ * 1 2 3
+ * 1 2 3
+ * line1 2 3 4 5
+ * 2 3 4 5
+ * 2 3 4 5
+ * line2 2 3 4 5
+ * 3 5 6
+ * 3 5 6
+ */
+ /* compute last line of this change */
+ last = dp->df_lnum[idx] + dp->df_count[idx] - 1;
+
+ /* 1. change completely above line1: nothing to do */
+ if (last >= line1 - 1)
+ {
+ /* 6. change below line2: only adjust for amount_after; also when
+ * "deleted" became zero when deleted all lines between two diffs */
+ if (dp->df_lnum[idx] - (deleted + inserted != 0) > line2)
+ {
+ if (amount_after == 0)
+ break; /* nothing left to change */
+ dp->df_lnum[idx] += amount_after;
+ }
+ else
+ {
+ check_unchanged = FALSE;
+
+ /* 2. 3. 4. 5.: inserted/deleted lines touching this diff. */
+ if (deleted > 0)
+ {
+ if (dp->df_lnum[idx] >= line1)
+ {
+ off = dp->df_lnum[idx] - lnum_deleted;
+ if (last <= line2)
+ {
+ /* 4. delete all lines of diff */
+ if (dp->df_next != NULL
+ && dp->df_next->df_lnum[idx] - 1 <= line2)
+ {
+ /* delete continues in next diff, only do
+ * lines until that one */
+ n = dp->df_next->df_lnum[idx] - lnum_deleted;
+ deleted -= n;
+ n -= dp->df_count[idx];
+ lnum_deleted = dp->df_next->df_lnum[idx];
+ }
+ else
+ n = deleted - dp->df_count[idx];
+ dp->df_count[idx] = 0;
+ }
+ else
+ {
+ /* 5. delete lines at or just before top of diff */
+ n = off;
+ dp->df_count[idx] -= line2 - dp->df_lnum[idx] + 1;
+ check_unchanged = TRUE;
+ }
+ dp->df_lnum[idx] = line1;
+ }
+ else
+ {
+ off = 0;
+ if (last < line2)
+ {
+ /* 2. delete at end of of diff */
+ dp->df_count[idx] -= last - lnum_deleted + 1;
+ if (dp->df_next != NULL
+ && dp->df_next->df_lnum[idx] - 1 <= line2)
+ {
+ /* delete continues in next diff, only do
+ * lines until that one */
+ n = dp->df_next->df_lnum[idx] - 1 - last;
+ deleted -= dp->df_next->df_lnum[idx]
+ - lnum_deleted;
+ lnum_deleted = dp->df_next->df_lnum[idx];
+ }
+ else
+ n = line2 - last;
+ check_unchanged = TRUE;
+ }
+ else
+ {
+ /* 3. delete lines inside the diff */
+ n = 0;
+ dp->df_count[idx] -= deleted;
+ }
+ }
+
+ for (i = 0; i < DB_COUNT; ++i)
+ if (tp->tp_diffbuf[i] != NULL && i != idx)
+ {
+ dp->df_lnum[i] -= off;
+ dp->df_count[i] += n;
+ }
+ }
+ else
+ {
+ if (dp->df_lnum[idx] <= line1)
+ {
+ /* inserted lines somewhere in this diff */
+ dp->df_count[idx] += inserted;
+ check_unchanged = TRUE;
+ }
+ else
+ /* inserted lines somewhere above this diff */
+ dp->df_lnum[idx] += inserted;
+ }
+
+ if (check_unchanged)
+ /* Check if inserted lines are equal, may reduce the
+ * size of the diff. TODO: also check for equal lines
+ * in the middle and perhaps split the block. */
+ diff_check_unchanged(tp, dp);
+ }
+ }
+
+ /* check if this block touches the previous one, may merge them. */
+ if (dprev != NULL && dprev->df_lnum[idx] + dprev->df_count[idx]
+ == dp->df_lnum[idx])
+ {
+ for (i = 0; i < DB_COUNT; ++i)
+ if (tp->tp_diffbuf[i] != NULL)
+ dprev->df_count[i] += dp->df_count[i];
+ dprev->df_next = dp->df_next;
+ vim_free(dp);
+ dp = dprev->df_next;
+ }
+ else
+ {
+ /* Advance to next entry. */
+ dprev = dp;
+ dp = dp->df_next;
+ }
+ }
+
+ dprev = NULL;
+ dp = tp->tp_first_diff;
+ while (dp != NULL)
+ {
+ /* All counts are zero, remove this entry. */
+ for (i = 0; i < DB_COUNT; ++i)
+ if (tp->tp_diffbuf[i] != NULL && dp->df_count[i] != 0)
+ break;
+ if (i == DB_COUNT)
+ {
+ dnext = dp->df_next;
+ vim_free(dp);
+ dp = dnext;
+ if (dprev == NULL)
+ tp->tp_first_diff = dnext;
+ else
+ dprev->df_next = dnext;
+ }
+ else
+ {
+ /* Advance to next entry. */
+ dprev = dp;
+ dp = dp->df_next;
+ }
+
+ }
+
+ if (tp == curtab)
+ {
+ diff_redraw(TRUE);
+
+ /* Need to recompute the scroll binding, may remove or add filler
+ * lines (e.g., when adding lines above w_topline). But it's slow when
+ * making many changes, postpone until redrawing. */
+ diff_need_scrollbind = TRUE;
+ }
+}
+
+/*
+ * Allocate a new diff block and link it between "dprev" and "dp".
+ */
+ static diff_T *
+diff_alloc_new(tabpage_T *tp, diff_T *dprev, diff_T *dp)
+{
+ diff_T *dnew;
+
+ dnew = (diff_T *)alloc((unsigned)sizeof(diff_T));
+ if (dnew != NULL)
+ {
+ dnew->df_next = dp;
+ if (dprev == NULL)
+ tp->tp_first_diff = dnew;
+ else
+ dprev->df_next = dnew;
+ }
+ return dnew;
+}
+
+/*
+ * Check if the diff block "dp" can be made smaller for lines at the start and
+ * end that are equal. Called after inserting lines.
+ * This may result in a change where all buffers have zero lines, the caller
+ * must take care of removing it.
+ */
+ static void
+diff_check_unchanged(tabpage_T *tp, diff_T *dp)
+{
+ int i_org;
+ int i_new;
+ int off_org, off_new;
+ char_u *line_org;
+ int dir = FORWARD;
+
+ /* Find the first buffers, use it as the original, compare the other
+ * buffer lines against this one. */
+ for (i_org = 0; i_org < DB_COUNT; ++i_org)
+ if (tp->tp_diffbuf[i_org] != NULL)
+ break;
+ if (i_org == DB_COUNT) /* safety check */
+ return;
+
+ if (diff_check_sanity(tp, dp) == FAIL)
+ return;
+
+ /* First check lines at the top, then at the bottom. */
+ off_org = 0;
+ off_new = 0;
+ for (;;)
+ {
+ /* Repeat until a line is found which is different or the number of
+ * lines has become zero. */
+ while (dp->df_count[i_org] > 0)
+ {
+ /* Copy the line, the next ml_get() will invalidate it. */
+ if (dir == BACKWARD)
+ off_org = dp->df_count[i_org] - 1;
+ line_org = vim_strsave(ml_get_buf(tp->tp_diffbuf[i_org],
+ dp->df_lnum[i_org] + off_org, FALSE));
+ if (line_org == NULL)
+ return;
+ for (i_new = i_org + 1; i_new < DB_COUNT; ++i_new)
+ {
+ if (tp->tp_diffbuf[i_new] == NULL)
+ continue;
+ if (dir == BACKWARD)
+ off_new = dp->df_count[i_new] - 1;
+ /* if other buffer doesn't have this line, it was inserted */
+ if (off_new < 0 || off_new >= dp->df_count[i_new])
+ break;
+ if (diff_cmp(line_org, ml_get_buf(tp->tp_diffbuf[i_new],
+ dp->df_lnum[i_new] + off_new, FALSE)) != 0)
+ break;
+ }
+ vim_free(line_org);
+
+ /* Stop when a line isn't equal in all diff buffers. */
+ if (i_new != DB_COUNT)
+ break;
+
+ /* Line matched in all buffers, remove it from the diff. */
+ for (i_new = i_org; i_new < DB_COUNT; ++i_new)
+ if (tp->tp_diffbuf[i_new] != NULL)
+ {
+ if (dir == FORWARD)
+ ++dp->df_lnum[i_new];
+ --dp->df_count[i_new];
+ }
+ }
+ if (dir == BACKWARD)
+ break;
+ dir = BACKWARD;
+ }
+}
+
+/*
+ * Check if a diff block doesn't contain invalid line numbers.
+ * This can happen when the diff program returns invalid results.
+ */
+ static int
+diff_check_sanity(tabpage_T *tp, diff_T *dp)
+{
+ int i;
+
+ for (i = 0; i < DB_COUNT; ++i)
+ if (tp->tp_diffbuf[i] != NULL)
+ if (dp->df_lnum[i] + dp->df_count[i] - 1
+ > tp->tp_diffbuf[i]->b_ml.ml_line_count)
+ return FAIL;
+ return OK;
+}
+
+/*
+ * Mark all diff buffers in the current tab page for redraw.
+ */
+ static void
+diff_redraw(
+ int dofold) // also recompute the folds
+{
+ win_T *wp;
+ int n;
+
+ FOR_ALL_WINDOWS(wp)
+ if (wp->w_p_diff)
+ {
+ redraw_win_later(wp, SOME_VALID);
+#ifdef FEAT_FOLDING
+ if (dofold && foldmethodIsDiff(wp))
+ foldUpdateAll(wp);
+#endif
+ /* A change may have made filler lines invalid, need to take care
+ * of that for other windows. */
+ n = diff_check(wp, wp->w_topline);
+ if ((wp != curwin && wp->w_topfill > 0) || n > 0)
+ {
+ if (wp->w_topfill > n)
+ wp->w_topfill = (n < 0 ? 0 : n);
+ else if (n > 0 && n > wp->w_topfill)
+ wp->w_topfill = n;
+ check_topfill(wp, FALSE);
+ }
+ }
+}
+
+ static void
+clear_diffin(diffin_T *din)
+{
+ if (din->din_fname == NULL)
+ {
+ vim_free(din->din_mmfile.ptr);
+ din->din_mmfile.ptr = NULL;
+ }
+ else
+ mch_remove(din->din_fname);
+}
+
+ static void
+clear_diffout(diffout_T *dout)
+{
+ if (dout->dout_fname == NULL)
+ ga_clear_strings(&dout->dout_ga);
+ else
+ mch_remove(dout->dout_fname);
+}
+
+/*
+ * Write buffer "buf" to a memory buffer.
+ * Return FAIL for failure.
+ */
+ static int
+diff_write_buffer(buf_T *buf, diffin_T *din)
+{
+ linenr_T lnum;
+ char_u *s;
+ long len = 0;
+ char_u *ptr;
+
+ // xdiff requires one big block of memory with all the text.
+ for (lnum = 1; lnum <= buf->b_ml.ml_line_count; ++lnum)
+ len += (long)STRLEN(ml_get_buf(buf, lnum, FALSE)) + 1;
+ ptr = lalloc(len, TRUE);
+ if (ptr == NULL)
+ {
+ // Allocating memory failed. This can happen, because we try to read
+ // the whole buffer text into memory. Set the failed flag, the diff
+ // will be retried with external diff. The flag is never reset.
+ buf->b_diff_failed = TRUE;
+ if (p_verbose > 0)
+ {
+ verbose_enter();
+ smsg(_("Not enough memory to use internal diff for buffer \"%s\""),
+ buf->b_fname);
+ verbose_leave();
+ }
+ return FAIL;
+ }
+ din->din_mmfile.ptr = (char *)ptr;
+ din->din_mmfile.size = len;
+
+ len = 0;
+ for (lnum = 1; lnum <= buf->b_ml.ml_line_count; ++lnum)
+ {
+ for (s = ml_get_buf(buf, lnum, FALSE); *s != NUL; )
+ {
+ if (diff_flags & DIFF_ICASE)
+ {
+ int c;
+ int orig_len;
+ char_u cbuf[MB_MAXBYTES + 1];
+
+ // xdiff doesn't support ignoring case, fold-case the text.
+ c = PTR2CHAR(s);
+ c = enc_utf8 ? utf_fold(c) : MB_TOLOWER(c);
+ orig_len = MB_PTR2LEN(s);
+ if (mb_char2bytes(c, cbuf) != orig_len)
+ // TODO: handle byte length difference
+ mch_memmove(ptr + len, s, orig_len);
+ else
+ mch_memmove(ptr + len, cbuf, orig_len);
+
+ s += orig_len;
+ len += orig_len;
+ }
+ else
+ ptr[len++] = *s++;
+ }
+ ptr[len++] = NL;
+ }
+ return OK;
+}
+
+/*
+ * Write buffer "buf" to file or memory buffer.
+ * Return FAIL for failure.
+ */
+ static int
+diff_write(buf_T *buf, diffin_T *din)
+{
+ int r;
+ char_u *save_ff;
+
+ if (din->din_fname == NULL)
+ return diff_write_buffer(buf, din);
+
+ // Always use 'fileformat' set to "unix".
+ save_ff = buf->b_p_ff;
+ buf->b_p_ff = vim_strsave((char_u *)FF_UNIX);
+ r = buf_write(buf, din->din_fname, NULL,
+ (linenr_T)1, buf->b_ml.ml_line_count,
+ NULL, FALSE, FALSE, FALSE, TRUE);
+ free_string_option(buf->b_p_ff);
+ buf->b_p_ff = save_ff;
+ return r;
+}
+
+/*
+ * Update the diffs for all buffers involved.
+ */
+ static void
+diff_try_update(
+ diffio_T *dio,
+ int idx_orig,
+ exarg_T *eap) // "eap" can be NULL
+{
+ buf_T *buf;
+ int idx_new;
+
+ if (dio->dio_internal)
+ {
+ ga_init2(&dio->dio_diff.dout_ga, sizeof(char *), 1000);
+ }
+ else
+ {
+ // We need three temp file names.
+ dio->dio_orig.din_fname = vim_tempname('o', TRUE);
+ dio->dio_new.din_fname = vim_tempname('n', TRUE);
+ dio->dio_diff.dout_fname = vim_tempname('d', TRUE);
+ if (dio->dio_orig.din_fname == NULL
+ || dio->dio_new.din_fname == NULL
+ || dio->dio_diff.dout_fname == NULL)
+ goto theend;
+ }
+
+ // Check external diff is actually working.
+ if (!dio->dio_internal && check_external_diff(dio) == FAIL)
+ goto theend;
+
+ // :diffupdate!
+ if (eap != NULL && eap->forceit)
+ for (idx_new = idx_orig; idx_new < DB_COUNT; ++idx_new)
+ {
+ buf = curtab->tp_diffbuf[idx_new];
+ if (buf_valid(buf))
+ buf_check_timestamp(buf, FALSE);
+ }
+
+ // Write the first buffer to a tempfile or mmfile_t.
+ buf = curtab->tp_diffbuf[idx_orig];
+ if (diff_write(buf, &dio->dio_orig) == FAIL)
+ goto theend;
+
+ // Make a difference between the first buffer and every other.
+ for (idx_new = idx_orig + 1; idx_new < DB_COUNT; ++idx_new)
+ {
+ buf = curtab->tp_diffbuf[idx_new];
+ if (buf == NULL || buf->b_ml.ml_mfp == NULL)
+ continue; // skip buffer that isn't loaded
+
+ // Write the other buffer and diff with the first one.
+ if (diff_write(buf, &dio->dio_new) == FAIL)
+ continue;
+ if (diff_file(dio) == FAIL)
+ continue;
+
+ // Read the diff output and add each entry to the diff list.
+ diff_read(idx_orig, idx_new, &dio->dio_diff);
+
+ clear_diffin(&dio->dio_new);
+ clear_diffout(&dio->dio_diff);
+ }
+ clear_diffin(&dio->dio_orig);
+
+theend:
+ vim_free(dio->dio_orig.din_fname);
+ vim_free(dio->dio_new.din_fname);
+ vim_free(dio->dio_diff.dout_fname);
+}
+
+/*
+ * Return TRUE if the options are set to use the internal diff library.
+ * Note that if the internal diff failed for one of the buffers, the external
+ * diff will be used anyway.
+ */
+ int
+diff_internal(void)
+{
+ return (diff_flags & DIFF_INTERNAL) != 0 && *p_dex == NUL;
+}
+
+/*
+ * Return TRUE if the internal diff failed for one of the diff buffers.
+ */
+ static int
+diff_internal_failed(void)
+{
+ int idx;
+
+ // Only need to do something when there is another buffer.
+ for (idx = 0; idx < DB_COUNT; ++idx)
+ if (curtab->tp_diffbuf[idx] != NULL
+ && curtab->tp_diffbuf[idx]->b_diff_failed)
+ return TRUE;
+ return FALSE;
+}
+
+/*
+ * Completely update the diffs for the buffers involved.
+ * When using the external "diff" command the buffers are written to a file,
+ * also for unmodified buffers (the file could have been produced by
+ * autocommands, e.g. the netrw plugin).
+ */
+ void
+ex_diffupdate(exarg_T *eap) // "eap" can be NULL
+{
+ int idx_orig;
+ int idx_new;
+ diffio_T diffio;
+ int had_diffs = curtab->tp_first_diff != NULL;
+
+ if (diff_busy)
+ {
+ diff_need_update = TRUE;
+ return;
+ }
+
+ // Delete all diffblocks.
+ diff_clear(curtab);
+ curtab->tp_diff_invalid = FALSE;
+
+ // Use the first buffer as the original text.
+ for (idx_orig = 0; idx_orig < DB_COUNT; ++idx_orig)
+ if (curtab->tp_diffbuf[idx_orig] != NULL)
+ break;
+ if (idx_orig == DB_COUNT)
+ goto theend;
+
+ // Only need to do something when there is another buffer.
+ for (idx_new = idx_orig + 1; idx_new < DB_COUNT; ++idx_new)
+ if (curtab->tp_diffbuf[idx_new] != NULL)
+ break;
+ if (idx_new == DB_COUNT)
+ goto theend;
+
+ // Only use the internal method if it did not fail for one of the buffers.
+ vim_memset(&diffio, 0, sizeof(diffio));
+ diffio.dio_internal = diff_internal() && !diff_internal_failed();
+
+ diff_try_update(&diffio, idx_orig, eap);
+ if (diffio.dio_internal && diff_internal_failed())
+ {
+ // Internal diff failed, use external diff instead.
+ vim_memset(&diffio, 0, sizeof(diffio));
+ diff_try_update(&diffio, idx_orig, eap);
+ }
+
+ // force updating cursor position on screen
+ curwin->w_valid_cursor.lnum = 0;
+
+theend:
+ // A redraw is needed if there were diffs and they were cleared, or there
+ // are diffs now, which means they got updated.
+ if (had_diffs || curtab->tp_first_diff != NULL)
+ {
+ diff_redraw(TRUE);
+ apply_autocmds(EVENT_DIFFUPDATED, NULL, NULL, FALSE, curbuf);
+ }
+}
+
+/*
+ * Do a quick test if "diff" really works. Otherwise it looks like there
+ * are no differences. Can't use the return value, it's non-zero when
+ * there are differences.
+ */
+ static int
+check_external_diff(diffio_T *diffio)
+{
+ FILE *fd;
+ int ok;
+ int io_error = FALSE;
+
+ // May try twice, first with "-a" and then without.
+ for (;;)
+ {
+ ok = FALSE;
+ fd = mch_fopen((char *)diffio->dio_orig.din_fname, "w");
+ if (fd == NULL)
+ io_error = TRUE;
+ else
+ {
+ if (fwrite("line1\n", (size_t)6, (size_t)1, fd) != 1)
+ io_error = TRUE;
+ fclose(fd);
+ fd = mch_fopen((char *)diffio->dio_new.din_fname, "w");
+ if (fd == NULL)
+ io_error = TRUE;
+ else
+ {
+ if (fwrite("line2\n", (size_t)6, (size_t)1, fd) != 1)
+ io_error = TRUE;
+ fclose(fd);
+ fd = NULL;
+ if (diff_file(diffio) == OK)
+ fd = mch_fopen((char *)diffio->dio_diff.dout_fname, "r");
+ if (fd == NULL)
+ io_error = TRUE;
+ else
+ {
+ char_u linebuf[LBUFLEN];
+
+ for (;;)
+ {
+ /* There must be a line that contains "1c1". */
+ if (tag_fgets(linebuf, LBUFLEN, fd))
+ break;
+ if (STRNCMP(linebuf, "1c1", 3) == 0)
+ ok = TRUE;
+ }
+ fclose(fd);
+ }
+ mch_remove(diffio->dio_diff.dout_fname);
+ mch_remove(diffio->dio_new.din_fname);
+ }
+ mch_remove(diffio->dio_orig.din_fname);
+ }
+
+#ifdef FEAT_EVAL
+ /* When using 'diffexpr' break here. */
+ if (*p_dex != NUL)
+ break;
+#endif
+
+#if defined(MSWIN)
+ /* If the "-a" argument works, also check if "--binary" works. */
+ if (ok && diff_a_works == MAYBE && diff_bin_works == MAYBE)
+ {
+ diff_a_works = TRUE;
+ diff_bin_works = TRUE;
+ continue;
+ }
+ if (!ok && diff_a_works == TRUE && diff_bin_works == TRUE)
+ {
+ /* Tried --binary, but it failed. "-a" works though. */
+ diff_bin_works = FALSE;
+ ok = TRUE;
+ }
+#endif
+
+ /* If we checked if "-a" works already, break here. */
+ if (diff_a_works != MAYBE)
+ break;
+ diff_a_works = ok;
+
+ /* If "-a" works break here, otherwise retry without "-a". */
+ if (ok)
+ break;
+ }
+ if (!ok)
+ {
+ if (io_error)
+ emsg(_("E810: Cannot read or write temp files"));
+ emsg(_("E97: Cannot create diffs"));
+ diff_a_works = MAYBE;
+#if defined(MSWIN)
+ diff_bin_works = MAYBE;
+#endif
+ return FAIL;
+ }
+ return OK;
+}
+
+/*
+ * Invoke the xdiff function.
+ */
+ static int
+diff_file_internal(diffio_T *diffio)
+{
+ xpparam_t param;
+ xdemitconf_t emit_cfg;
+ xdemitcb_t emit_cb;
+
+ vim_memset(&param, 0, sizeof(param));
+ vim_memset(&emit_cfg, 0, sizeof(emit_cfg));
+ vim_memset(&emit_cb, 0, sizeof(emit_cb));
+
+ param.flags = diff_algorithm;
+
+ if (diff_flags & DIFF_IWHITE)
+ param.flags |= XDF_IGNORE_WHITESPACE_CHANGE;
+ if (diff_flags & DIFF_IWHITEALL)
+ param.flags |= XDF_IGNORE_WHITESPACE;
+ if (diff_flags & DIFF_IWHITEEOL)
+ param.flags |= XDF_IGNORE_WHITESPACE_AT_EOL;
+ if (diff_flags & DIFF_IBLANK)
+ param.flags |= XDF_IGNORE_BLANK_LINES;
+
+ emit_cfg.ctxlen = 0; // don't need any diff_context here
+ emit_cb.priv = &diffio->dio_diff;
+ emit_cb.outf = xdiff_out;
+ if (xdl_diff(&diffio->dio_orig.din_mmfile,
+ &diffio->dio_new.din_mmfile,
+ &param, &emit_cfg, &emit_cb) < 0)
+ {
+ emsg(_("E960: Problem creating the internal diff"));
+ return FAIL;
+ }
+ return OK;
+}
+
+/*
+ * Make a diff between files "tmp_orig" and "tmp_new", results in "tmp_diff".
+ * return OK or FAIL;
+ */
+ static int
+diff_file(diffio_T *dio)
+{
+ char_u *cmd;
+ size_t len;
+ char_u *tmp_orig = dio->dio_orig.din_fname;
+ char_u *tmp_new = dio->dio_new.din_fname;
+ char_u *tmp_diff = dio->dio_diff.dout_fname;
+
+#ifdef FEAT_EVAL
+ if (*p_dex != NUL)
+ {
+ // Use 'diffexpr' to generate the diff file.
+ eval_diff(tmp_orig, tmp_new, tmp_diff);
+ return OK;
+ }
+ else
+#endif
+ // Use xdiff for generating the diff.
+ if (dio->dio_internal)
+ {
+ return diff_file_internal(dio);
+ }
+ else
+ {
+ len = STRLEN(tmp_orig) + STRLEN(tmp_new)
+ + STRLEN(tmp_diff) + STRLEN(p_srr) + 27;
+ cmd = alloc((unsigned)len);
+ if (cmd == NULL)
+ return FAIL;
+
+ // We don't want $DIFF_OPTIONS to get in the way.
+ if (getenv("DIFF_OPTIONS"))
+ vim_setenv((char_u *)"DIFF_OPTIONS", (char_u *)"");
+
+ // Build the diff command and execute it. Always use -a, binary
+ // differences are of no use. Ignore errors, diff returns
+ // non-zero when differences have been found.
+ vim_snprintf((char *)cmd, len, "diff %s%s%s%s%s%s%s%s %s",
+ diff_a_works == FALSE ? "" : "-a ",
+#if defined(MSWIN)
+ diff_bin_works == TRUE ? "--binary " : "",
+#else
+ "",
+#endif
+ (diff_flags & DIFF_IWHITE) ? "-b " : "",
+ (diff_flags & DIFF_IWHITEALL) ? "-w " : "",
+ (diff_flags & DIFF_IWHITEEOL) ? "-Z " : "",
+ (diff_flags & DIFF_IBLANK) ? "-B " : "",
+ (diff_flags & DIFF_ICASE) ? "-i " : "",
+ tmp_orig, tmp_new);
+ append_redir(cmd, (int)len, p_srr, tmp_diff);
+ block_autocmds(); // avoid ShellCmdPost stuff
+ (void)call_shell(cmd, SHELL_FILTER|SHELL_SILENT|SHELL_DOOUT);
+ unblock_autocmds();
+ vim_free(cmd);
+ return OK;
+ }
+}
+
+/*
+ * Create a new version of a file from the current buffer and a diff file.
+ * The buffer is written to a file, also for unmodified buffers (the file
+ * could have been produced by autocommands, e.g. the netrw plugin).
+ */
+ void
+ex_diffpatch(exarg_T *eap)
+{
+ char_u *tmp_orig; /* name of original temp file */
+ char_u *tmp_new; /* name of patched temp file */
+ char_u *buf = NULL;
+ size_t buflen;
+ win_T *old_curwin = curwin;
+ char_u *newname = NULL; /* name of patched file buffer */
+#ifdef UNIX
+ char_u dirbuf[MAXPATHL];
+ char_u *fullname = NULL;
+#endif
+#ifdef FEAT_BROWSE
+ char_u *browseFile = NULL;
+ int browse_flag = cmdmod.browse;
+#endif
+ stat_T st;
+ char_u *esc_name = NULL;
+
+#ifdef FEAT_BROWSE
+ if (cmdmod.browse)
+ {
+ browseFile = do_browse(0, (char_u *)_("Patch file"),
+ eap->arg, NULL, NULL,
+ (char_u *)_(BROWSE_FILTER_ALL_FILES), NULL);
+ if (browseFile == NULL)
+ return; /* operation cancelled */
+ eap->arg = browseFile;
+ cmdmod.browse = FALSE; /* don't let do_ecmd() browse again */
+ }
+#endif
+
+ /* We need two temp file names. */
+ tmp_orig = vim_tempname('o', FALSE);
+ tmp_new = vim_tempname('n', FALSE);
+ if (tmp_orig == NULL || tmp_new == NULL)
+ goto theend;
+
+ /* Write the current buffer to "tmp_orig". */
+ if (buf_write(curbuf, tmp_orig, NULL,
+ (linenr_T)1, curbuf->b_ml.ml_line_count,
+ NULL, FALSE, FALSE, FALSE, TRUE) == FAIL)
+ goto theend;
+
+#ifdef UNIX
+ /* Get the absolute path of the patchfile, changing directory below. */
+ fullname = FullName_save(eap->arg, FALSE);
+#endif
+ esc_name = vim_strsave_shellescape(
+# ifdef UNIX
+ fullname != NULL ? fullname :
+# endif
+ eap->arg, TRUE, TRUE);
+ if (esc_name == NULL)
+ goto theend;
+ buflen = STRLEN(tmp_orig) + STRLEN(esc_name) + STRLEN(tmp_new) + 16;
+ buf = alloc((unsigned)buflen);
+ if (buf == NULL)
+ goto theend;
+
+#ifdef UNIX
+ /* Temporarily chdir to /tmp, to avoid patching files in the current
+ * directory when the patch file contains more than one patch. When we
+ * have our own temp dir use that instead, it will be cleaned up when we
+ * exit (any .rej files created). Don't change directory if we can't
+ * return to the current. */
+ if (mch_dirname(dirbuf, MAXPATHL) != OK || mch_chdir((char *)dirbuf) != 0)
+ dirbuf[0] = NUL;
+ else
+ {
+# ifdef TEMPDIRNAMES
+ if (vim_tempdir != NULL)
+ vim_ignored = mch_chdir((char *)vim_tempdir);
+ else
+# endif
+ vim_ignored = mch_chdir("/tmp");
+ shorten_fnames(TRUE);
+ }
+#endif
+
+#ifdef FEAT_EVAL
+ if (*p_pex != NUL)
+ /* Use 'patchexpr' to generate the new file. */
+ eval_patch(tmp_orig,
+# ifdef UNIX
+ fullname != NULL ? fullname :
+# endif
+ eap->arg, tmp_new);
+ else
+#endif
+ {
+ /* Build the patch command and execute it. Ignore errors. Switch to
+ * cooked mode to allow the user to respond to prompts. */
+ vim_snprintf((char *)buf, buflen, "patch -o %s %s < %s",
+ tmp_new, tmp_orig, esc_name);
+ block_autocmds(); /* Avoid ShellCmdPost stuff */
+ (void)call_shell(buf, SHELL_FILTER | SHELL_COOKED);
+ unblock_autocmds();
+ }
+
+#ifdef UNIX
+ if (dirbuf[0] != NUL)
+ {
+ if (mch_chdir((char *)dirbuf) != 0)
+ emsg(_(e_prev_dir));
+ shorten_fnames(TRUE);
+ }
+#endif
+
+ /* patch probably has written over the screen */
+ redraw_later(CLEAR);
+
+ /* Delete any .orig or .rej file created. */
+ STRCPY(buf, tmp_new);
+ STRCAT(buf, ".orig");
+ mch_remove(buf);
+ STRCPY(buf, tmp_new);
+ STRCAT(buf, ".rej");
+ mch_remove(buf);
+
+ /* Only continue if the output file was created. */
+ if (mch_stat((char *)tmp_new, &st) < 0 || st.st_size == 0)
+ emsg(_("E816: Cannot read patch output"));
+ else
+ {
+ if (curbuf->b_fname != NULL)
+ {
+ newname = vim_strnsave(curbuf->b_fname,
+ (int)(STRLEN(curbuf->b_fname) + 4));
+ if (newname != NULL)
+ STRCAT(newname, ".new");
+ }
+
+#ifdef FEAT_GUI
+ need_mouse_correct = TRUE;
+#endif
+ /* don't use a new tab page, each tab page has its own diffs */
+ cmdmod.tab = 0;
+
+ if (win_split(0, (diff_flags & DIFF_VERTICAL) ? WSP_VERT : 0) != FAIL)
+ {
+ /* Pretend it was a ":split fname" command */
+ eap->cmdidx = CMD_split;
+ eap->arg = tmp_new;
+ do_exedit(eap, old_curwin);
+
+ /* check that split worked and editing tmp_new */
+ if (curwin != old_curwin && win_valid(old_curwin))
+ {
+ /* Set 'diff', 'scrollbind' on and 'wrap' off. */
+ diff_win_options(curwin, TRUE);
+ diff_win_options(old_curwin, TRUE);
+
+ if (newname != NULL)
+ {
+ /* do a ":file filename.new" on the patched buffer */
+ eap->arg = newname;
+ ex_file(eap);
+
+ /* Do filetype detection with the new name. */
+ if (au_has_group((char_u *)"filetypedetect"))
+ do_cmdline_cmd((char_u *)":doau filetypedetect BufRead");
+ }
+ }
+ }
+ }
+
+theend:
+ if (tmp_orig != NULL)
+ mch_remove(tmp_orig);
+ vim_free(tmp_orig);
+ if (tmp_new != NULL)
+ mch_remove(tmp_new);
+ vim_free(tmp_new);
+ vim_free(newname);
+ vim_free(buf);
+#ifdef UNIX
+ vim_free(fullname);
+#endif
+ vim_free(esc_name);
+#ifdef FEAT_BROWSE
+ vim_free(browseFile);
+ cmdmod.browse = browse_flag;
+#endif
+}
+
+/*
+ * Split the window and edit another file, setting options to show the diffs.
+ */
+ void
+ex_diffsplit(exarg_T *eap)
+{
+ win_T *old_curwin = curwin;
+ bufref_T old_curbuf;
+
+ set_bufref(&old_curbuf, curbuf);
+#ifdef FEAT_GUI
+ need_mouse_correct = TRUE;
+#endif
+ /* Need to compute w_fraction when no redraw happened yet. */
+ validate_cursor();
+ set_fraction(curwin);
+
+ /* don't use a new tab page, each tab page has its own diffs */
+ cmdmod.tab = 0;
+
+ if (win_split(0, (diff_flags & DIFF_VERTICAL) ? WSP_VERT : 0) != FAIL)
+ {
+ /* Pretend it was a ":split fname" command */
+ eap->cmdidx = CMD_split;
+ curwin->w_p_diff = TRUE;
+ do_exedit(eap, old_curwin);
+
+ if (curwin != old_curwin) /* split must have worked */
+ {
+ /* Set 'diff', 'scrollbind' on and 'wrap' off. */
+ diff_win_options(curwin, TRUE);
+ if (win_valid(old_curwin))
+ {
+ diff_win_options(old_curwin, TRUE);
+
+ if (bufref_valid(&old_curbuf))
+ /* Move the cursor position to that of the old window. */
+ curwin->w_cursor.lnum = diff_get_corresponding_line(
+ old_curbuf.br_buf, old_curwin->w_cursor.lnum);
+ }
+ /* Now that lines are folded scroll to show the cursor at the same
+ * relative position. */
+ scroll_to_fraction(curwin, curwin->w_height);
+ }
+ }
+}
+
+/*
+ * Set options to show diffs for the current window.
+ */
+ void
+ex_diffthis(exarg_T *eap UNUSED)
+{
+ /* Set 'diff', 'scrollbind' on and 'wrap' off. */
+ diff_win_options(curwin, TRUE);
+}
+
+ static void
+set_diff_option(win_T *wp, int value)
+{
+ win_T *old_curwin = curwin;
+
+ curwin = wp;
+ curbuf = curwin->w_buffer;
+ ++curbuf_lock;
+ set_option_value((char_u *)"diff", (long)value, NULL, OPT_LOCAL);
+ --curbuf_lock;
+ curwin = old_curwin;
+ curbuf = curwin->w_buffer;
+}
+
+/*
+ * Set options in window "wp" for diff mode.
+ */
+ void
+diff_win_options(
+ win_T *wp,
+ int addbuf) /* Add buffer to diff. */
+{
+# ifdef FEAT_FOLDING
+ win_T *old_curwin = curwin;
+
+ /* close the manually opened folds */
+ curwin = wp;
+ newFoldLevel();
+ curwin = old_curwin;
+# endif
+
+ /* Use 'scrollbind' and 'cursorbind' when available */
+ if (!wp->w_p_diff)
+ wp->w_p_scb_save = wp->w_p_scb;
+ wp->w_p_scb = TRUE;
+ if (!wp->w_p_diff)
+ wp->w_p_crb_save = wp->w_p_crb;
+ wp->w_p_crb = TRUE;
+ if (!wp->w_p_diff)
+ wp->w_p_wrap_save = wp->w_p_wrap;
+ wp->w_p_wrap = FALSE;
+# ifdef FEAT_FOLDING
+ curwin = wp;
+ curbuf = curwin->w_buffer;
+ if (!wp->w_p_diff)
+ {
+ if (wp->w_p_diff_saved)
+ free_string_option(wp->w_p_fdm_save);
+ wp->w_p_fdm_save = vim_strsave(wp->w_p_fdm);
+ }
+ set_string_option_direct((char_u *)"fdm", -1, (char_u *)"diff",
+ OPT_LOCAL|OPT_FREE, 0);
+ curwin = old_curwin;
+ curbuf = curwin->w_buffer;
+ if (!wp->w_p_diff)
+ {
+ wp->w_p_fdc_save = wp->w_p_fdc;
+ wp->w_p_fen_save = wp->w_p_fen;
+ wp->w_p_fdl_save = wp->w_p_fdl;
+ }
+ wp->w_p_fdc = diff_foldcolumn;
+ wp->w_p_fen = TRUE;
+ wp->w_p_fdl = 0;
+ foldUpdateAll(wp);
+ /* make sure topline is not halfway a fold */
+ changed_window_setting_win(wp);
+# endif
+ if (vim_strchr(p_sbo, 'h') == NULL)
+ do_cmdline_cmd((char_u *)"set sbo+=hor");
+ /* Save the current values, to be restored in ex_diffoff(). */
+ wp->w_p_diff_saved = TRUE;
+
+ set_diff_option(wp, TRUE);
+
+ if (addbuf)
+ diff_buf_add(wp->w_buffer);
+ redraw_win_later(wp, NOT_VALID);
+}
+
+/*
+ * Set options not to show diffs. For the current window or all windows.
+ * Only in the current tab page.
+ */
+ void
+ex_diffoff(exarg_T *eap)
+{
+ win_T *wp;
+ int diffwin = FALSE;
+
+ FOR_ALL_WINDOWS(wp)
+ {
+ if (eap->forceit ? wp->w_p_diff : wp == curwin)
+ {
+ /* Set 'diff' off. If option values were saved in
+ * diff_win_options(), restore the ones whose settings seem to have
+ * been left over from diff mode. */
+ set_diff_option(wp, FALSE);
+
+ if (wp->w_p_diff_saved)
+ {
+
+ if (wp->w_p_scb)
+ wp->w_p_scb = wp->w_p_scb_save;
+ if (wp->w_p_crb)
+ wp->w_p_crb = wp->w_p_crb_save;
+ if (!wp->w_p_wrap)
+ wp->w_p_wrap = wp->w_p_wrap_save;
+#ifdef FEAT_FOLDING
+ free_string_option(wp->w_p_fdm);
+ wp->w_p_fdm = vim_strsave(
+ *wp->w_p_fdm_save ? wp->w_p_fdm_save : (char_u*)"manual");
+
+ if (wp->w_p_fdc == diff_foldcolumn)
+ wp->w_p_fdc = wp->w_p_fdc_save;
+ if (wp->w_p_fdl == 0)
+ wp->w_p_fdl = wp->w_p_fdl_save;
+
+ /* Only restore 'foldenable' when 'foldmethod' is not
+ * "manual", otherwise we continue to show the diff folds. */
+ if (wp->w_p_fen)
+ wp->w_p_fen = foldmethodIsManual(wp) ? FALSE
+ : wp->w_p_fen_save;
+
+ foldUpdateAll(wp);
+#endif
+ }
+ /* remove filler lines */
+ wp->w_topfill = 0;
+
+ /* make sure topline is not halfway a fold and cursor is
+ * invalidated */
+ changed_window_setting_win(wp);
+
+ /* Note: 'sbo' is not restored, it's a global option. */
+ diff_buf_adjust(wp);
+ }
+ diffwin |= wp->w_p_diff;
+ }
+
+ /* Also remove hidden buffers from the list. */
+ if (eap->forceit)
+ diff_buf_clear();
+
+ /* Remove "hor" from from 'scrollopt' if there are no diff windows left. */
+ if (!diffwin && vim_strchr(p_sbo, 'h') != NULL)
+ do_cmdline_cmd((char_u *)"set sbo-=hor");
+}
+
+/*
+ * Read the diff output and add each entry to the diff list.
+ */
+ static void
+diff_read(
+ int idx_orig, // idx of original file
+ int idx_new, // idx of new file
+ diffout_T *dout) // diff output
+{
+ FILE *fd = NULL;
+ int line_idx = 0;
+ diff_T *dprev = NULL;
+ diff_T *dp = curtab->tp_first_diff;
+ diff_T *dn, *dpl;
+ char_u linebuf[LBUFLEN]; /* only need to hold the diff line */
+ char_u *line;
+ long off;
+ int i;
+ linenr_T lnum_orig, lnum_new;
+ long count_orig, count_new;
+ int notset = TRUE; /* block "*dp" not set yet */
+ enum {
+ DIFF_ED,
+ DIFF_UNIFIED,
+ DIFF_NONE
+ } diffstyle = DIFF_NONE;
+
+ if (dout->dout_fname == NULL)
+ {
+ diffstyle = DIFF_UNIFIED;
+ }
+ else
+ {
+ fd = mch_fopen((char *)dout->dout_fname, "r");
+ if (fd == NULL)
+ {
+ emsg(_("E98: Cannot read diff output"));
+ return;
+ }
+ }
+
+ for (;;)
+ {
+ if (fd == NULL)
+ {
+ if (line_idx >= dout->dout_ga.ga_len)
+ break; // did last line
+ line = ((char_u **)dout->dout_ga.ga_data)[line_idx++];
+ }
+ else
+ {
+ if (tag_fgets(linebuf, LBUFLEN, fd))
+ break; // end of file
+ line = linebuf;
+ }
+
+ if (diffstyle == DIFF_NONE)
+ {
+ // Determine diff style.
+ // ed like diff looks like this:
+ // {first}[,{last}]c{first}[,{last}]
+ // {first}a{first}[,{last}]
+ // {first}[,{last}]d{first}
+ //
+ // unified diff looks like this:
+ // --- file1 2018-03-20 13:23:35.783153140 +0100
+ // +++ file2 2018-03-20 13:23:41.183156066 +0100
+ // @@ -1,3 +1,5 @@
+ if (isdigit(*line))
+ diffstyle = DIFF_ED;
+ else if ((STRNCMP(line, "@@ ", 3) == 0))
+ diffstyle = DIFF_UNIFIED;
+ else if ((STRNCMP(line, "--- ", 4) == 0)
+ && (tag_fgets(linebuf, LBUFLEN, fd) == 0)
+ && (STRNCMP(line, "+++ ", 4) == 0)
+ && (tag_fgets(linebuf, LBUFLEN, fd) == 0)
+ && (STRNCMP(line, "@@ ", 3) == 0))
+ diffstyle = DIFF_UNIFIED;
+ else
+ // Format not recognized yet, skip over this line. Cygwin diff
+ // may put a warning at the start of the file.
+ continue;
+ }
+
+ if (diffstyle == DIFF_ED)
+ {
+ if (!isdigit(*line))
+ continue; // not the start of a diff block
+ if (parse_diff_ed(line, &lnum_orig, &count_orig,
+ &lnum_new, &count_new) == FAIL)
+ continue;
+ }
+ else if (diffstyle == DIFF_UNIFIED)
+ {
+ if (STRNCMP(line, "@@ ", 3) != 0)
+ continue; // not the start of a diff block
+ if (parse_diff_unified(line, &lnum_orig, &count_orig,
+ &lnum_new, &count_new) == FAIL)
+ continue;
+ }
+ else
+ {
+ emsg(_("E959: Invalid diff format."));
+ break;
+ }
+
+ // Go over blocks before the change, for which orig and new are equal.
+ // Copy blocks from orig to new.
+ while (dp != NULL
+ && lnum_orig > dp->df_lnum[idx_orig] + dp->df_count[idx_orig])
+ {
+ if (notset)
+ diff_copy_entry(dprev, dp, idx_orig, idx_new);
+ dprev = dp;
+ dp = dp->df_next;
+ notset = TRUE;
+ }
+
+ if (dp != NULL
+ && lnum_orig <= dp->df_lnum[idx_orig] + dp->df_count[idx_orig]
+ && lnum_orig + count_orig >= dp->df_lnum[idx_orig])
+ {
+ // New block overlaps with existing block(s).
+ // First find last block that overlaps.
+ for (dpl = dp; dpl->df_next != NULL; dpl = dpl->df_next)
+ if (lnum_orig + count_orig < dpl->df_next->df_lnum[idx_orig])
+ break;
+
+ // If the newly found block starts before the old one, set the
+ // start back a number of lines.
+ off = dp->df_lnum[idx_orig] - lnum_orig;
+ if (off > 0)
+ {
+ for (i = idx_orig; i < idx_new; ++i)
+ if (curtab->tp_diffbuf[i] != NULL)
+ dp->df_lnum[i] -= off;
+ dp->df_lnum[idx_new] = lnum_new;
+ dp->df_count[idx_new] = count_new;
+ }
+ else if (notset)
+ {
+ // new block inside existing one, adjust new block
+ dp->df_lnum[idx_new] = lnum_new + off;
+ dp->df_count[idx_new] = count_new - off;
+ }
+ else
+ // second overlap of new block with existing block
+ dp->df_count[idx_new] += count_new - count_orig
+ + dpl->df_lnum[idx_orig] + dpl->df_count[idx_orig]
+ - (dp->df_lnum[idx_orig] + dp->df_count[idx_orig]);
+
+ // Adjust the size of the block to include all the lines to the
+ // end of the existing block or the new diff, whatever ends last.
+ off = (lnum_orig + count_orig)
+ - (dpl->df_lnum[idx_orig] + dpl->df_count[idx_orig]);
+ if (off < 0)
+ {
+ // new change ends in existing block, adjust the end if not
+ // done already
+ if (notset)
+ dp->df_count[idx_new] += -off;
+ off = 0;
+ }
+ for (i = idx_orig; i < idx_new; ++i)
+ if (curtab->tp_diffbuf[i] != NULL)
+ dp->df_count[i] = dpl->df_lnum[i] + dpl->df_count[i]
+ - dp->df_lnum[i] + off;
+
+ // Delete the diff blocks that have been merged into one.
+ dn = dp->df_next;
+ dp->df_next = dpl->df_next;
+ while (dn != dp->df_next)
+ {
+ dpl = dn->df_next;
+ vim_free(dn);
+ dn = dpl;
+ }
+ }
+ else
+ {
+ // Allocate a new diffblock.
+ dp = diff_alloc_new(curtab, dprev, dp);
+ if (dp == NULL)
+ goto done;
+
+ dp->df_lnum[idx_orig] = lnum_orig;
+ dp->df_count[idx_orig] = count_orig;
+ dp->df_lnum[idx_new] = lnum_new;
+ dp->df_count[idx_new] = count_new;
+
+ // Set values for other buffers, these must be equal to the
+ // original buffer, otherwise there would have been a change
+ // already.
+ for (i = idx_orig + 1; i < idx_new; ++i)
+ if (curtab->tp_diffbuf[i] != NULL)
+ diff_copy_entry(dprev, dp, idx_orig, i);
+ }
+ notset = FALSE; // "*dp" has been set
+ }
+
+ // for remaining diff blocks orig and new are equal
+ while (dp != NULL)
+ {
+ if (notset)
+ diff_copy_entry(dprev, dp, idx_orig, idx_new);
+ dprev = dp;
+ dp = dp->df_next;
+ notset = TRUE;
+ }
+
+done:
+ if (fd != NULL)
+ fclose(fd);
+}
+
+/*
+ * Copy an entry at "dp" from "idx_orig" to "idx_new".
+ */
+ static void
+diff_copy_entry(
+ diff_T *dprev,
+ diff_T *dp,
+ int idx_orig,
+ int idx_new)
+{
+ long off;
+
+ if (dprev == NULL)
+ off = 0;
+ else
+ off = (dprev->df_lnum[idx_orig] + dprev->df_count[idx_orig])
+ - (dprev->df_lnum[idx_new] + dprev->df_count[idx_new]);
+ dp->df_lnum[idx_new] = dp->df_lnum[idx_orig] - off;
+ dp->df_count[idx_new] = dp->df_count[idx_orig];
+}
+
+/*
+ * Clear the list of diffblocks for tab page "tp".
+ */
+ void
+diff_clear(tabpage_T *tp)
+{
+ diff_T *p, *next_p;
+
+ for (p = tp->tp_first_diff; p != NULL; p = next_p)
+ {
+ next_p = p->df_next;
+ vim_free(p);
+ }
+ tp->tp_first_diff = NULL;
+}
+
+/*
+ * Check diff status for line "lnum" in buffer "buf":
+ * Returns 0 for nothing special
+ * Returns -1 for a line that should be highlighted as changed.
+ * Returns -2 for a line that should be highlighted as added/deleted.
+ * Returns > 0 for inserting that many filler lines above it (never happens
+ * when 'diffopt' doesn't contain "filler").
+ * This should only be used for windows where 'diff' is set.
+ */
+ int
+diff_check(win_T *wp, linenr_T lnum)
+{
+ int idx; /* index in tp_diffbuf[] for this buffer */
+ diff_T *dp;
+ int maxcount;
+ int i;
+ buf_T *buf = wp->w_buffer;
+ int cmp;
+
+ if (curtab->tp_diff_invalid)
+ ex_diffupdate(NULL); /* update after a big change */
+
+ if (curtab->tp_first_diff == NULL || !wp->w_p_diff) /* no diffs at all */
+ return 0;
+
+ /* safety check: "lnum" must be a buffer line */
+ if (lnum < 1 || lnum > buf->b_ml.ml_line_count + 1)
+ return 0;
+
+ idx = diff_buf_idx(buf);
+ if (idx == DB_COUNT)
+ return 0; /* no diffs for buffer "buf" */
+
+#ifdef FEAT_FOLDING
+ /* A closed fold never has filler lines. */
+ if (hasFoldingWin(wp, lnum, NULL, NULL, TRUE, NULL))
+ return 0;
+#endif
+
+ /* search for a change that includes "lnum" in the list of diffblocks. */
+ for (dp = curtab->tp_first_diff; dp != NULL; dp = dp->df_next)
+ if (lnum <= dp->df_lnum[idx] + dp->df_count[idx])
+ break;
+ if (dp == NULL || lnum < dp->df_lnum[idx])
+ return 0;
+
+ if (lnum < dp->df_lnum[idx] + dp->df_count[idx])
+ {
+ int zero = FALSE;
+
+ /* Changed or inserted line. If the other buffers have a count of
+ * zero, the lines were inserted. If the other buffers have the same
+ * count, check if the lines are identical. */
+ cmp = FALSE;
+ for (i = 0; i < DB_COUNT; ++i)
+ if (i != idx && curtab->tp_diffbuf[i] != NULL)
+ {
+ if (dp->df_count[i] == 0)
+ zero = TRUE;
+ else
+ {
+ if (dp->df_count[i] != dp->df_count[idx])
+ return -1; /* nr of lines changed. */
+ cmp = TRUE;
+ }
+ }
+ if (cmp)
+ {
+ /* Compare all lines. If they are equal the lines were inserted
+ * in some buffers, deleted in others, but not changed. */
+ for (i = 0; i < DB_COUNT; ++i)
+ if (i != idx && curtab->tp_diffbuf[i] != NULL
+ && dp->df_count[i] != 0)
+ if (!diff_equal_entry(dp, idx, i))
+ return -1;
+ }
+ /* If there is no buffer with zero lines then there is no difference
+ * any longer. Happens when making a change (or undo) that removes
+ * the difference. Can't remove the entry here, we might be halfway
+ * updating the window. Just report the text as unchanged. Other
+ * windows might still show the change though. */
+ if (zero == FALSE)
+ return 0;
+ return -2;
+ }
+
+ /* If 'diffopt' doesn't contain "filler", return 0. */
+ if (!(diff_flags & DIFF_FILLER))
+ return 0;
+
+ /* Insert filler lines above the line just below the change. Will return
+ * 0 when this buf had the max count. */
+ maxcount = 0;
+ for (i = 0; i < DB_COUNT; ++i)
+ if (curtab->tp_diffbuf[i] != NULL && dp->df_count[i] > maxcount)
+ maxcount = dp->df_count[i];
+ return maxcount - dp->df_count[idx];
+}
+
+/*
+ * Compare two entries in diff "*dp" and return TRUE if they are equal.
+ */
+ static int
+diff_equal_entry(diff_T *dp, int idx1, int idx2)
+{
+ int i;
+ char_u *line;
+ int cmp;
+
+ if (dp->df_count[idx1] != dp->df_count[idx2])
+ return FALSE;
+ if (diff_check_sanity(curtab, dp) == FAIL)
+ return FALSE;
+ for (i = 0; i < dp->df_count[idx1]; ++i)
+ {
+ line = vim_strsave(ml_get_buf(curtab->tp_diffbuf[idx1],
+ dp->df_lnum[idx1] + i, FALSE));
+ if (line == NULL)
+ return FALSE;
+ cmp = diff_cmp(line, ml_get_buf(curtab->tp_diffbuf[idx2],
+ dp->df_lnum[idx2] + i, FALSE));
+ vim_free(line);
+ if (cmp != 0)
+ return FALSE;
+ }
+ return TRUE;
+}
+
+/*
+ * Compare the characters at "p1" and "p2". If they are equal (possibly
+ * ignoring case) return TRUE and set "len" to the number of bytes.
+ */
+ static int
+diff_equal_char(char_u *p1, char_u *p2, int *len)
+{
+ int l = (*mb_ptr2len)(p1);
+
+ if (l != (*mb_ptr2len)(p2))
+ return FALSE;
+ if (l > 1)
+ {
+ if (STRNCMP(p1, p2, l) != 0
+ && (!enc_utf8
+ || !(diff_flags & DIFF_ICASE)
+ || utf_fold(utf_ptr2char(p1))
+ != utf_fold(utf_ptr2char(p2))))
+ return FALSE;
+ *len = l;
+ }
+ else
+ {
+ if ((*p1 != *p2)
+ && (!(diff_flags & DIFF_ICASE)
+ || TOLOWER_LOC(*p1) != TOLOWER_LOC(*p2)))
+ return FALSE;
+ *len = 1;
+ }
+ return TRUE;
+}
+
+/*
+ * Compare strings "s1" and "s2" according to 'diffopt'.
+ * Return non-zero when they are different.
+ */
+ static int
+diff_cmp(char_u *s1, char_u *s2)
+{
+ char_u *p1, *p2;
+ int l;
+
+ if ((diff_flags & DIFF_IBLANK)
+ && (*skipwhite(s1) == NUL || *skipwhite(s2) == NUL))
+ return 0;
+
+ if ((diff_flags & (DIFF_ICASE | ALL_WHITE_DIFF)) == 0)
+ return STRCMP(s1, s2);
+ if ((diff_flags & DIFF_ICASE) && !(diff_flags & ALL_WHITE_DIFF))
+ return MB_STRICMP(s1, s2);
+
+ p1 = s1;
+ p2 = s2;
+
+ // Ignore white space changes and possibly ignore case.
+ while (*p1 != NUL && *p2 != NUL)
+ {
+ if (((diff_flags & DIFF_IWHITE)
+ && VIM_ISWHITE(*p1) && VIM_ISWHITE(*p2))
+ || ((diff_flags & DIFF_IWHITEALL)
+ && (VIM_ISWHITE(*p1) || VIM_ISWHITE(*p2))))
+ {
+ p1 = skipwhite(p1);
+ p2 = skipwhite(p2);
+ }
+ else
+ {
+ if (!diff_equal_char(p1, p2, &l))
+ break;
+ p1 += l;
+ p2 += l;
+ }
+ }
+
+ // Ignore trailing white space.
+ p1 = skipwhite(p1);
+ p2 = skipwhite(p2);
+ if (*p1 != NUL || *p2 != NUL)
+ return 1;
+ return 0;
+}
+
+/*
+ * Return the number of filler lines above "lnum".
+ */
+ int
+diff_check_fill(win_T *wp, linenr_T lnum)
+{
+ int n;
+
+ /* be quick when there are no filler lines */
+ if (!(diff_flags & DIFF_FILLER))
+ return 0;
+ n = diff_check(wp, lnum);
+ if (n <= 0)
+ return 0;
+ return n;
+}
+
+/*
+ * Set the topline of "towin" to match the position in "fromwin", so that they
+ * show the same diff'ed lines.
+ */
+ void
+diff_set_topline(win_T *fromwin, win_T *towin)
+{
+ buf_T *frombuf = fromwin->w_buffer;
+ linenr_T lnum = fromwin->w_topline;
+ int fromidx;
+ int toidx;
+ diff_T *dp;
+ int max_count;
+ int i;
+
+ fromidx = diff_buf_idx(frombuf);
+ if (fromidx == DB_COUNT)
+ return; /* safety check */
+
+ if (curtab->tp_diff_invalid)
+ ex_diffupdate(NULL); /* update after a big change */
+
+ towin->w_topfill = 0;
+
+ /* search for a change that includes "lnum" in the list of diffblocks. */
+ for (dp = curtab->tp_first_diff; dp != NULL; dp = dp->df_next)
+ if (lnum <= dp->df_lnum[fromidx] + dp->df_count[fromidx])
+ break;
+ if (dp == NULL)
+ {
+ /* After last change, compute topline relative to end of file; no
+ * filler lines. */
+ towin->w_topline = towin->w_buffer->b_ml.ml_line_count
+ - (frombuf->b_ml.ml_line_count - lnum);
+ }
+ else
+ {
+ /* Find index for "towin". */
+ toidx = diff_buf_idx(towin->w_buffer);
+ if (toidx == DB_COUNT)
+ return; /* safety check */
+
+ towin->w_topline = lnum + (dp->df_lnum[toidx] - dp->df_lnum[fromidx]);
+ if (lnum >= dp->df_lnum[fromidx])
+ {
+ /* Inside a change: compute filler lines. With three or more
+ * buffers we need to know the largest count. */
+ max_count = 0;
+ for (i = 0; i < DB_COUNT; ++i)
+ if (curtab->tp_diffbuf[i] != NULL
+ && max_count < dp->df_count[i])
+ max_count = dp->df_count[i];
+
+ if (dp->df_count[toidx] == dp->df_count[fromidx])
+ {
+ /* same number of lines: use same filler count */
+ towin->w_topfill = fromwin->w_topfill;
+ }
+ else if (dp->df_count[toidx] > dp->df_count[fromidx])
+ {
+ if (lnum == dp->df_lnum[fromidx] + dp->df_count[fromidx])
+ {
+ /* more lines in towin and fromwin doesn't show diff
+ * lines, only filler lines */
+ if (max_count - fromwin->w_topfill >= dp->df_count[toidx])
+ {
+ /* towin also only shows filler lines */
+ towin->w_topline = dp->df_lnum[toidx]
+ + dp->df_count[toidx];
+ towin->w_topfill = fromwin->w_topfill;
+ }
+ else
+ /* towin still has some diff lines to show */
+ towin->w_topline = dp->df_lnum[toidx]
+ + max_count - fromwin->w_topfill;
+ }
+ }
+ else if (towin->w_topline >= dp->df_lnum[toidx]
+ + dp->df_count[toidx])
+ {
+ /* less lines in towin and no diff lines to show: compute
+ * filler lines */
+ towin->w_topline = dp->df_lnum[toidx] + dp->df_count[toidx];
+ if (diff_flags & DIFF_FILLER)
+ {
+ if (lnum == dp->df_lnum[fromidx] + dp->df_count[fromidx])
+ /* fromwin is also out of diff lines */
+ towin->w_topfill = fromwin->w_topfill;
+ else
+ /* fromwin has some diff lines */
+ towin->w_topfill = dp->df_lnum[fromidx]
+ + max_count - lnum;
+ }
+ }
+ }
+ }
+
+ /* safety check (if diff info gets outdated strange things may happen) */
+ towin->w_botfill = FALSE;
+ if (towin->w_topline > towin->w_buffer->b_ml.ml_line_count)
+ {
+ towin->w_topline = towin->w_buffer->b_ml.ml_line_count;
+ towin->w_botfill = TRUE;
+ }
+ if (towin->w_topline < 1)
+ {
+ towin->w_topline = 1;
+ towin->w_topfill = 0;
+ }
+
+ /* When w_topline changes need to recompute w_botline and cursor position */
+ invalidate_botline_win(towin);
+ changed_line_abv_curs_win(towin);
+
+ check_topfill(towin, FALSE);
+#ifdef FEAT_FOLDING
+ (void)hasFoldingWin(towin, towin->w_topline, &towin->w_topline,
+ NULL, TRUE, NULL);
+#endif
+}
+
+/*
+ * This is called when 'diffopt' is changed.
+ */
+ int
+diffopt_changed(void)
+{
+ char_u *p;
+ int diff_context_new = 6;
+ int diff_flags_new = 0;
+ int diff_foldcolumn_new = 2;
+ long diff_algorithm_new = 0;
+ long diff_indent_heuristic = 0;
+ tabpage_T *tp;
+
+ p = p_dip;
+ while (*p != NUL)
+ {
+ if (STRNCMP(p, "filler", 6) == 0)
+ {
+ p += 6;
+ diff_flags_new |= DIFF_FILLER;
+ }
+ else if (STRNCMP(p, "context:", 8) == 0 && VIM_ISDIGIT(p[8]))
+ {
+ p += 8;
+ diff_context_new = getdigits(&p);
+ }
+ else if (STRNCMP(p, "iblank", 6) == 0)
+ {
+ p += 6;
+ diff_flags_new |= DIFF_IBLANK;
+ }
+ else if (STRNCMP(p, "icase", 5) == 0)
+ {
+ p += 5;
+ diff_flags_new |= DIFF_ICASE;
+ }
+ else if (STRNCMP(p, "iwhiteall", 9) == 0)
+ {
+ p += 9;
+ diff_flags_new |= DIFF_IWHITEALL;
+ }
+ else if (STRNCMP(p, "iwhiteeol", 9) == 0)
+ {
+ p += 9;
+ diff_flags_new |= DIFF_IWHITEEOL;
+ }
+ else if (STRNCMP(p, "iwhite", 6) == 0)
+ {
+ p += 6;
+ diff_flags_new |= DIFF_IWHITE;
+ }
+ else if (STRNCMP(p, "horizontal", 10) == 0)
+ {
+ p += 10;
+ diff_flags_new |= DIFF_HORIZONTAL;
+ }
+ else if (STRNCMP(p, "vertical", 8) == 0)
+ {
+ p += 8;
+ diff_flags_new |= DIFF_VERTICAL;
+ }
+ else if (STRNCMP(p, "foldcolumn:", 11) == 0 && VIM_ISDIGIT(p[11]))
+ {
+ p += 11;
+ diff_foldcolumn_new = getdigits(&p);
+ }
+ else if (STRNCMP(p, "hiddenoff", 9) == 0)
+ {
+ p += 9;
+ diff_flags_new |= DIFF_HIDDEN_OFF;
+ }
+ else if (STRNCMP(p, "indent-heuristic", 16) == 0)
+ {
+ p += 16;
+ diff_indent_heuristic = XDF_INDENT_HEURISTIC;
+ }
+ else if (STRNCMP(p, "internal", 8) == 0)
+ {
+ p += 8;
+ diff_flags_new |= DIFF_INTERNAL;
+ }
+ else if (STRNCMP(p, "algorithm:", 10) == 0)
+ {
+ p += 10;
+ if (STRNCMP(p, "myers", 5) == 0)
+ {
+ p += 5;
+ diff_algorithm_new = 0;
+ }
+ else if (STRNCMP(p, "minimal", 7) == 0)
+ {
+ p += 7;
+ diff_algorithm_new = XDF_NEED_MINIMAL;
+ }
+ else if (STRNCMP(p, "patience", 8) == 0)
+ {
+ p += 8;
+ diff_algorithm_new = XDF_PATIENCE_DIFF;
+ }
+ else if (STRNCMP(p, "histogram", 9) == 0)
+ {
+ p += 9;
+ diff_algorithm_new = XDF_HISTOGRAM_DIFF;
+ }
+ else
+ return FAIL;
+ }
+
+ if (*p != ',' && *p != NUL)
+ return FAIL;
+ if (*p == ',')
+ ++p;
+ }
+
+ diff_algorithm_new |= diff_indent_heuristic;
+
+ /* Can't have both "horizontal" and "vertical". */
+ if ((diff_flags_new & DIFF_HORIZONTAL) && (diff_flags_new & DIFF_VERTICAL))
+ return FAIL;
+
+ // If flags were added or removed, or the algorithm was changed, need to
+ // update the diff.
+ if (diff_flags != diff_flags_new || diff_algorithm != diff_algorithm_new)
+ FOR_ALL_TABPAGES(tp)
+ tp->tp_diff_invalid = TRUE;
+
+ diff_flags = diff_flags_new;
+ diff_context = diff_context_new;
+ diff_foldcolumn = diff_foldcolumn_new;
+ diff_algorithm = diff_algorithm_new;
+
+ diff_redraw(TRUE);
+
+ /* recompute the scroll binding with the new option value, may
+ * remove or add filler lines */
+ check_scrollbind((linenr_T)0, 0L);
+
+ return OK;
+}
+
+/*
+ * Return TRUE if 'diffopt' contains "horizontal".
+ */
+ int
+diffopt_horizontal(void)
+{
+ return (diff_flags & DIFF_HORIZONTAL) != 0;
+}
+
+/*
+ * Return TRUE if 'diffopt' contains "hiddenoff".
+ */
+ int
+diffopt_hiddenoff(void)
+{
+ return (diff_flags & DIFF_HIDDEN_OFF) != 0;
+}
+
+/*
+ * Find the difference within a changed line.
+ * Returns TRUE if the line was added, no other buffer has it.
+ */
+ int
+diff_find_change(
+ win_T *wp,
+ linenr_T lnum,
+ int *startp, /* first char of the change */
+ int *endp) /* last char of the change */
+{
+ char_u *line_org;
+ char_u *line_new;
+ int i;
+ int si_org, si_new;
+ int ei_org, ei_new;
+ diff_T *dp;
+ int idx;
+ int off;
+ int added = TRUE;
+ char_u *p1, *p2;
+ int l;
+
+ /* Make a copy of the line, the next ml_get() will invalidate it. */
+ line_org = vim_strsave(ml_get_buf(wp->w_buffer, lnum, FALSE));
+ if (line_org == NULL)
+ return FALSE;
+
+ idx = diff_buf_idx(wp->w_buffer);
+ if (idx == DB_COUNT) /* cannot happen */
+ {
+ vim_free(line_org);
+ return FALSE;
+ }
+
+ /* search for a change that includes "lnum" in the list of diffblocks. */
+ for (dp = curtab->tp_first_diff; dp != NULL; dp = dp->df_next)
+ if (lnum <= dp->df_lnum[idx] + dp->df_count[idx])
+ break;
+ if (dp == NULL || diff_check_sanity(curtab, dp) == FAIL)
+ {
+ vim_free(line_org);
+ return FALSE;
+ }
+
+ off = lnum - dp->df_lnum[idx];
+
+ for (i = 0; i < DB_COUNT; ++i)
+ if (curtab->tp_diffbuf[i] != NULL && i != idx)
+ {
+ /* Skip lines that are not in the other change (filler lines). */
+ if (off >= dp->df_count[i])
+ continue;
+ added = FALSE;
+ line_new = ml_get_buf(curtab->tp_diffbuf[i],
+ dp->df_lnum[i] + off, FALSE);
+
+ /* Search for start of difference */
+ si_org = si_new = 0;
+ while (line_org[si_org] != NUL)
+ {
+ if (((diff_flags & DIFF_IWHITE)
+ && VIM_ISWHITE(line_org[si_org])
+ && VIM_ISWHITE(line_new[si_new]))
+ || ((diff_flags & DIFF_IWHITEALL)
+ && (VIM_ISWHITE(line_org[si_org])
+ || VIM_ISWHITE(line_new[si_new]))))
+ {
+ si_org = (int)(skipwhite(line_org + si_org) - line_org);
+ si_new = (int)(skipwhite(line_new + si_new) - line_new);
+ }
+ else
+ {
+ if (!diff_equal_char(line_org + si_org, line_new + si_new,
+ &l))
+ break;
+ si_org += l;
+ si_new += l;
+ }
+ }
+ if (has_mbyte)
+ {
+ /* Move back to first byte of character in both lines (may
+ * have "nn^" in line_org and "n^ in line_new). */
+ si_org -= (*mb_head_off)(line_org, line_org + si_org);
+ si_new -= (*mb_head_off)(line_new, line_new + si_new);
+ }
+ if (*startp > si_org)
+ *startp = si_org;
+
+ /* Search for end of difference, if any. */
+ if (line_org[si_org] != NUL || line_new[si_new] != NUL)
+ {
+ ei_org = (int)STRLEN(line_org);
+ ei_new = (int)STRLEN(line_new);
+ while (ei_org >= *startp && ei_new >= si_new
+ && ei_org >= 0 && ei_new >= 0)
+ {
+ if (((diff_flags & DIFF_IWHITE)
+ && VIM_ISWHITE(line_org[ei_org])
+ && VIM_ISWHITE(line_new[ei_new]))
+ || ((diff_flags & DIFF_IWHITEALL)
+ && (VIM_ISWHITE(line_org[ei_org])
+ || VIM_ISWHITE(line_new[ei_new]))))
+ {
+ while (ei_org >= *startp
+ && VIM_ISWHITE(line_org[ei_org]))
+ --ei_org;
+ while (ei_new >= si_new
+ && VIM_ISWHITE(line_new[ei_new]))
+ --ei_new;
+ }
+ else
+ {
+ p1 = line_org + ei_org;
+ p2 = line_new + ei_new;
+ p1 -= (*mb_head_off)(line_org, p1);
+ p2 -= (*mb_head_off)(line_new, p2);
+ if (!diff_equal_char(p1, p2, &l))
+ break;
+ ei_org -= l;
+ ei_new -= l;
+ }
+ }
+ if (*endp < ei_org)
+ *endp = ei_org;
+ }
+ }
+
+ vim_free(line_org);
+ return added;
+}
+
+#if defined(FEAT_FOLDING) || defined(PROTO)
+/*
+ * Return TRUE if line "lnum" is not close to a diff block, this line should
+ * be in a fold.
+ * Return FALSE if there are no diff blocks at all in this window.
+ */
+ int
+diff_infold(win_T *wp, linenr_T lnum)
+{
+ int i;
+ int idx = -1;
+ int other = FALSE;
+ diff_T *dp;
+
+ /* Return if 'diff' isn't set. */
+ if (!wp->w_p_diff)
+ return FALSE;
+
+ for (i = 0; i < DB_COUNT; ++i)
+ {
+ if (curtab->tp_diffbuf[i] == wp->w_buffer)
+ idx = i;
+ else if (curtab->tp_diffbuf[i] != NULL)
+ other = TRUE;
+ }
+
+ /* return here if there are no diffs in the window */
+ if (idx == -1 || !other)
+ return FALSE;
+
+ if (curtab->tp_diff_invalid)
+ ex_diffupdate(NULL); /* update after a big change */
+
+ /* Return if there are no diff blocks. All lines will be folded. */
+ if (curtab->tp_first_diff == NULL)
+ return TRUE;
+
+ for (dp = curtab->tp_first_diff; dp != NULL; dp = dp->df_next)
+ {
+ /* If this change is below the line there can't be any further match. */
+ if (dp->df_lnum[idx] - diff_context > lnum)
+ break;
+ /* If this change ends before the line we have a match. */
+ if (dp->df_lnum[idx] + dp->df_count[idx] + diff_context > lnum)
+ return FALSE;
+ }
+ return TRUE;
+}
+#endif
+
+/*
+ * "dp" and "do" commands.
+ */
+ void
+nv_diffgetput(int put, long count)
+{
+ exarg_T ea;
+ char_u buf[30];
+
+#ifdef FEAT_JOB_CHANNEL
+ if (bt_prompt(curbuf))
+ {
+ vim_beep(BO_OPER);
+ return;
+ }
+#endif
+ if (count == 0)
+ ea.arg = (char_u *)"";
+ else
+ {
+ vim_snprintf((char *)buf, 30, "%ld", count);
+ ea.arg = buf;
+ }
+ if (put)
+ ea.cmdidx = CMD_diffput;
+ else
+ ea.cmdidx = CMD_diffget;
+ ea.addr_count = 0;
+ ea.line1 = curwin->w_cursor.lnum;
+ ea.line2 = curwin->w_cursor.lnum;
+ ex_diffgetput(&ea);
+}
+
+/*
+ * ":diffget"
+ * ":diffput"
+ */
+ void
+ex_diffgetput(exarg_T *eap)
+{
+ linenr_T lnum;
+ int count;
+ linenr_T off = 0;
+ diff_T *dp;
+ diff_T *dprev;
+ diff_T *dfree;
+ int idx_cur;
+ int idx_other;
+ int idx_from;
+ int idx_to;
+ int i;
+ int added;
+ char_u *p;
+ aco_save_T aco;
+ buf_T *buf;
+ int start_skip, end_skip;
+ int new_count;
+ int buf_empty;
+ int found_not_ma = FALSE;
+
+ /* Find the current buffer in the list of diff buffers. */
+ idx_cur = diff_buf_idx(curbuf);
+ if (idx_cur == DB_COUNT)
+ {
+ emsg(_("E99: Current buffer is not in diff mode"));
+ return;
+ }
+
+ if (*eap->arg == NUL)
+ {
+ /* No argument: Find the other buffer in the list of diff buffers. */
+ for (idx_other = 0; idx_other < DB_COUNT; ++idx_other)
+ if (curtab->tp_diffbuf[idx_other] != curbuf
+ && curtab->tp_diffbuf[idx_other] != NULL)
+ {
+ if (eap->cmdidx != CMD_diffput
+ || curtab->tp_diffbuf[idx_other]->b_p_ma)
+ break;
+ found_not_ma = TRUE;
+ }
+ if (idx_other == DB_COUNT)
+ {
+ if (found_not_ma)
+ emsg(_("E793: No other buffer in diff mode is modifiable"));
+ else
+ emsg(_("E100: No other buffer in diff mode"));
+ return;
+ }
+
+ /* Check that there isn't a third buffer in the list */
+ for (i = idx_other + 1; i < DB_COUNT; ++i)
+ if (curtab->tp_diffbuf[i] != curbuf
+ && curtab->tp_diffbuf[i] != NULL
+ && (eap->cmdidx != CMD_diffput || curtab->tp_diffbuf[i]->b_p_ma))
+ {
+ emsg(_("E101: More than two buffers in diff mode, don't know which one to use"));
+ return;
+ }
+ }
+ else
+ {
+ /* Buffer number or pattern given. Ignore trailing white space. */
+ p = eap->arg + STRLEN(eap->arg);
+ while (p > eap->arg && VIM_ISWHITE(p[-1]))
+ --p;
+ for (i = 0; vim_isdigit(eap->arg[i]) && eap->arg + i < p; ++i)
+ ;
+ if (eap->arg + i == p) /* digits only */
+ i = atol((char *)eap->arg);
+ else
+ {
+ i = buflist_findpat(eap->arg, p, FALSE, TRUE, FALSE);
+ if (i < 0)
+ return; /* error message already given */
+ }
+ buf = buflist_findnr(i);
+ if (buf == NULL)
+ {
+ semsg(_("E102: Can't find buffer \"%s\""), eap->arg);
+ return;
+ }
+ if (buf == curbuf)
+ return; /* nothing to do */
+ idx_other = diff_buf_idx(buf);
+ if (idx_other == DB_COUNT)
+ {
+ semsg(_("E103: Buffer \"%s\" is not in diff mode"), eap->arg);
+ return;
+ }
+ }
+
+ diff_busy = TRUE;
+
+ /* When no range given include the line above or below the cursor. */
+ if (eap->addr_count == 0)
+ {
+ /* Make it possible that ":diffget" on the last line gets line below
+ * the cursor line when there is no difference above the cursor. */
+ if (eap->cmdidx == CMD_diffget
+ && eap->line1 == curbuf->b_ml.ml_line_count
+ && diff_check(curwin, eap->line1) == 0
+ && (eap->line1 == 1 || diff_check(curwin, eap->line1 - 1) == 0))
+ ++eap->line2;
+ else if (eap->line1 > 0)
+ --eap->line1;
+ }
+
+ if (eap->cmdidx == CMD_diffget)
+ {
+ idx_from = idx_other;
+ idx_to = idx_cur;
+ }
+ else
+ {
+ idx_from = idx_cur;
+ idx_to = idx_other;
+ /* Need to make the other buffer the current buffer to be able to make
+ * changes in it. */
+ /* set curwin/curbuf to buf and save a few things */
+ aucmd_prepbuf(&aco, curtab->tp_diffbuf[idx_other]);
+ }
+
+ /* May give the warning for a changed buffer here, which can trigger the
+ * FileChangedRO autocommand, which may do nasty things and mess
+ * everything up. */
+ if (!curbuf->b_changed)
+ {
+ change_warning(0);
+ if (diff_buf_idx(curbuf) != idx_to)
+ {
+ emsg(_("E787: Buffer changed unexpectedly"));
+ goto theend;
+ }
+ }
+
+ dprev = NULL;
+ for (dp = curtab->tp_first_diff; dp != NULL; )
+ {
+ if (dp->df_lnum[idx_cur] > eap->line2 + off)
+ break; /* past the range that was specified */
+
+ dfree = NULL;
+ lnum = dp->df_lnum[idx_to];
+ count = dp->df_count[idx_to];
+ if (dp->df_lnum[idx_cur] + dp->df_count[idx_cur] > eap->line1 + off
+ && u_save(lnum - 1, lnum + count) != FAIL)
+ {
+ /* Inside the specified range and saving for undo worked. */
+ start_skip = 0;
+ end_skip = 0;
+ if (eap->addr_count > 0)
+ {
+ /* A range was specified: check if lines need to be skipped. */
+ start_skip = eap->line1 + off - dp->df_lnum[idx_cur];
+ if (start_skip > 0)
+ {
+ /* range starts below start of current diff block */
+ if (start_skip > count)
+ {
+ lnum += count;
+ count = 0;
+ }
+ else
+ {
+ count -= start_skip;
+ lnum += start_skip;
+ }
+ }
+ else
+ start_skip = 0;
+
+ end_skip = dp->df_lnum[idx_cur] + dp->df_count[idx_cur] - 1
+ - (eap->line2 + off);
+ if (end_skip > 0)
+ {
+ /* range ends above end of current/from diff block */
+ if (idx_cur == idx_from) /* :diffput */
+ {
+ i = dp->df_count[idx_cur] - start_skip - end_skip;
+ if (count > i)
+ count = i;
+ }
+ else /* :diffget */
+ {
+ count -= end_skip;
+ end_skip = dp->df_count[idx_from] - start_skip - count;
+ if (end_skip < 0)
+ end_skip = 0;
+ }
+ }
+ else
+ end_skip = 0;
+ }
+
+ buf_empty = BUFEMPTY();
+ added = 0;
+ for (i = 0; i < count; ++i)
+ {
+ /* remember deleting the last line of the buffer */
+ buf_empty = curbuf->b_ml.ml_line_count == 1;
+ ml_delete(lnum, FALSE);
+ --added;
+ }
+ for (i = 0; i < dp->df_count[idx_from] - start_skip - end_skip; ++i)
+ {
+ linenr_T nr;
+
+ nr = dp->df_lnum[idx_from] + start_skip + i;
+ if (nr > curtab->tp_diffbuf[idx_from]->b_ml.ml_line_count)
+ break;
+ p = vim_strsave(ml_get_buf(curtab->tp_diffbuf[idx_from],
+ nr, FALSE));
+ if (p != NULL)
+ {
+ ml_append(lnum + i - 1, p, 0, FALSE);
+ vim_free(p);
+ ++added;
+ if (buf_empty && curbuf->b_ml.ml_line_count == 2)
+ {
+ /* Added the first line into an empty buffer, need to
+ * delete the dummy empty line. */
+ buf_empty = FALSE;
+ ml_delete((linenr_T)2, FALSE);
+ }
+ }
+ }
+ new_count = dp->df_count[idx_to] + added;
+ dp->df_count[idx_to] = new_count;
+
+ if (start_skip == 0 && end_skip == 0)
+ {
+ /* Check if there are any other buffers and if the diff is
+ * equal in them. */
+ for (i = 0; i < DB_COUNT; ++i)
+ if (curtab->tp_diffbuf[i] != NULL && i != idx_from
+ && i != idx_to
+ && !diff_equal_entry(dp, idx_from, i))
+ break;
+ if (i == DB_COUNT)
+ {
+ /* delete the diff entry, the buffers are now equal here */
+ dfree = dp;
+ dp = dp->df_next;
+ if (dprev == NULL)
+ curtab->tp_first_diff = dp;
+ else
+ dprev->df_next = dp;
+ }
+ }
+
+ /* Adjust marks. This will change the following entries! */
+ if (added != 0)
+ {
+ mark_adjust(lnum, lnum + count - 1, (long)MAXLNUM, (long)added);
+ if (curwin->w_cursor.lnum >= lnum)
+ {
+ /* Adjust the cursor position if it's in/after the changed
+ * lines. */
+ if (curwin->w_cursor.lnum >= lnum + count)
+ curwin->w_cursor.lnum += added;
+ else if (added < 0)
+ curwin->w_cursor.lnum = lnum;
+ }
+ }
+ changed_lines(lnum, 0, lnum + count, (long)added);
+
+ if (dfree != NULL)
+ {
+ /* Diff is deleted, update folds in other windows. */
+#ifdef FEAT_FOLDING
+ diff_fold_update(dfree, idx_to);
+#endif
+ vim_free(dfree);
+ }
+ else
+ /* mark_adjust() may have changed the count in a wrong way */
+ dp->df_count[idx_to] = new_count;
+
+ /* When changing the current buffer, keep track of line numbers */
+ if (idx_cur == idx_to)
+ off += added;
+ }
+
+ /* If before the range or not deleted, go to next diff. */
+ if (dfree == NULL)
+ {
+ dprev = dp;
+ dp = dp->df_next;
+ }
+ }
+
+ /* restore curwin/curbuf and a few other things */
+ if (eap->cmdidx != CMD_diffget)
+ {
+ /* Syncing undo only works for the current buffer, but we change
+ * another buffer. Sync undo if the command was typed. This isn't
+ * 100% right when ":diffput" is used in a function or mapping. */
+ if (KeyTyped)
+ u_sync(FALSE);
+ aucmd_restbuf(&aco);
+ }
+
+theend:
+ diff_busy = FALSE;
+ if (diff_need_update)
+ ex_diffupdate(NULL);
+
+ // Check that the cursor is on a valid character and update its
+ // position. When there were filler lines the topline has become
+ // invalid.
+ check_cursor();
+ changed_line_abv_curs();
+
+ if (diff_need_update)
+ // redraw already done by ex_diffupdate()
+ diff_need_update = FALSE;
+ else
+ {
+ // Also need to redraw the other buffers.
+ diff_redraw(FALSE);
+ apply_autocmds(EVENT_DIFFUPDATED, NULL, NULL, FALSE, curbuf);
+ }
+}
+
+#ifdef FEAT_FOLDING
+/*
+ * Update folds for all diff buffers for entry "dp".
+ * Skip buffer with index "skip_idx".
+ * When there are no diffs, all folds are removed.
+ */
+ static void
+diff_fold_update(diff_T *dp, int skip_idx)
+{
+ int i;
+ win_T *wp;
+
+ FOR_ALL_WINDOWS(wp)
+ for (i = 0; i < DB_COUNT; ++i)
+ if (curtab->tp_diffbuf[i] == wp->w_buffer && i != skip_idx)
+ foldUpdate(wp, dp->df_lnum[i],
+ dp->df_lnum[i] + dp->df_count[i]);
+}
+#endif
+
+/*
+ * Return TRUE if buffer "buf" is in diff-mode.
+ */
+ int
+diff_mode_buf(buf_T *buf)
+{
+ tabpage_T *tp;
+
+ FOR_ALL_TABPAGES(tp)
+ if (diff_buf_idx_tp(buf, tp) != DB_COUNT)
+ return TRUE;
+ return FALSE;
+}
+
+/*
+ * Move "count" times in direction "dir" to the next diff block.
+ * Return FAIL if there isn't such a diff block.
+ */
+ int
+diff_move_to(int dir, long count)
+{
+ int idx;
+ linenr_T lnum = curwin->w_cursor.lnum;
+ diff_T *dp;
+
+ idx = diff_buf_idx(curbuf);
+ if (idx == DB_COUNT || curtab->tp_first_diff == NULL)
+ return FAIL;
+
+ if (curtab->tp_diff_invalid)
+ ex_diffupdate(NULL); /* update after a big change */
+
+ if (curtab->tp_first_diff == NULL) /* no diffs today */
+ return FAIL;
+
+ while (--count >= 0)
+ {
+ /* Check if already before first diff. */
+ if (dir == BACKWARD && lnum <= curtab->tp_first_diff->df_lnum[idx])
+ break;
+
+ for (dp = curtab->tp_first_diff; ; dp = dp->df_next)
+ {
+ if (dp == NULL)
+ break;
+ if ((dir == FORWARD && lnum < dp->df_lnum[idx])
+ || (dir == BACKWARD
+ && (dp->df_next == NULL
+ || lnum <= dp->df_next->df_lnum[idx])))
+ {
+ lnum = dp->df_lnum[idx];
+ break;
+ }
+ }
+ }
+
+ /* don't end up past the end of the file */
+ if (lnum > curbuf->b_ml.ml_line_count)
+ lnum = curbuf->b_ml.ml_line_count;
+
+ /* When the cursor didn't move at all we fail. */
+ if (lnum == curwin->w_cursor.lnum)
+ return FAIL;
+
+ setpcmark();
+ curwin->w_cursor.lnum = lnum;
+ curwin->w_cursor.col = 0;
+
+ return OK;
+}
+
+/*
+ * Return the line number in the current window that is closest to "lnum1" in
+ * "buf1" in diff mode.
+ */
+ static linenr_T
+diff_get_corresponding_line_int(
+ buf_T *buf1,
+ linenr_T lnum1)
+{
+ int idx1;
+ int idx2;
+ diff_T *dp;
+ int baseline = 0;
+
+ idx1 = diff_buf_idx(buf1);
+ idx2 = diff_buf_idx(curbuf);
+ if (idx1 == DB_COUNT || idx2 == DB_COUNT || curtab->tp_first_diff == NULL)
+ return lnum1;
+
+ if (curtab->tp_diff_invalid)
+ ex_diffupdate(NULL); /* update after a big change */
+
+ if (curtab->tp_first_diff == NULL) /* no diffs today */
+ return lnum1;
+
+ for (dp = curtab->tp_first_diff; dp != NULL; dp = dp->df_next)
+ {
+ if (dp->df_lnum[idx1] > lnum1)
+ return lnum1 - baseline;
+ if ((dp->df_lnum[idx1] + dp->df_count[idx1]) > lnum1)
+ {
+ /* Inside the diffblock */
+ baseline = lnum1 - dp->df_lnum[idx1];
+ if (baseline > dp->df_count[idx2])
+ baseline = dp->df_count[idx2];
+
+ return dp->df_lnum[idx2] + baseline;
+ }
+ if ( (dp->df_lnum[idx1] == lnum1)
+ && (dp->df_count[idx1] == 0)
+ && (dp->df_lnum[idx2] <= curwin->w_cursor.lnum)
+ && ((dp->df_lnum[idx2] + dp->df_count[idx2])
+ > curwin->w_cursor.lnum))
+ /*
+ * Special case: if the cursor is just after a zero-count
+ * block (i.e. all filler) and the target cursor is already
+ * inside the corresponding block, leave the target cursor
+ * unmoved. This makes repeated CTRL-W W operations work
+ * as expected.
+ */
+ return curwin->w_cursor.lnum;
+ baseline = (dp->df_lnum[idx1] + dp->df_count[idx1])
+ - (dp->df_lnum[idx2] + dp->df_count[idx2]);
+ }
+
+ /* If we get here then the cursor is after the last diff */
+ return lnum1 - baseline;
+}
+
+/*
+ * Return the line number in the current window that is closest to "lnum1" in
+ * "buf1" in diff mode. Checks the line number to be valid.
+ */
+ linenr_T
+diff_get_corresponding_line(buf_T *buf1, linenr_T lnum1)
+{
+ linenr_T lnum = diff_get_corresponding_line_int(buf1, lnum1);
+
+ /* don't end up past the end of the file */
+ if (lnum > curbuf->b_ml.ml_line_count)
+ return curbuf->b_ml.ml_line_count;
+ return lnum;
+}
+
+/*
+ * For line "lnum" in the current window find the equivalent lnum in window
+ * "wp", compensating for inserted/deleted lines.
+ */
+ linenr_T
+diff_lnum_win(linenr_T lnum, win_T *wp)
+{
+ diff_T *dp;
+ int idx;
+ int i;
+ linenr_T n;
+
+ idx = diff_buf_idx(curbuf);
+ if (idx == DB_COUNT) /* safety check */
+ return (linenr_T)0;
+
+ if (curtab->tp_diff_invalid)
+ ex_diffupdate(NULL); /* update after a big change */
+
+ /* search for a change that includes "lnum" in the list of diffblocks. */
+ for (dp = curtab->tp_first_diff; dp != NULL; dp = dp->df_next)
+ if (lnum <= dp->df_lnum[idx] + dp->df_count[idx])
+ break;
+
+ /* When after the last change, compute relative to the last line number. */
+ if (dp == NULL)
+ return wp->w_buffer->b_ml.ml_line_count
+ - (curbuf->b_ml.ml_line_count - lnum);
+
+ /* Find index for "wp". */
+ i = diff_buf_idx(wp->w_buffer);
+ if (i == DB_COUNT) /* safety check */
+ return (linenr_T)0;
+
+ n = lnum + (dp->df_lnum[i] - dp->df_lnum[idx]);
+ if (n > dp->df_lnum[i] + dp->df_count[i])
+ n = dp->df_lnum[i] + dp->df_count[i];
+ return n;
+}
+
+/*
+ * Handle an ED style diff line.
+ * Return FAIL if the line does not contain diff info.
+ */
+ static int
+parse_diff_ed(
+ char_u *line,
+ linenr_T *lnum_orig,
+ long *count_orig,
+ linenr_T *lnum_new,
+ long *count_new)
+{
+ char_u *p;
+ long f1, l1, f2, l2;
+ int difftype;
+
+ // The line must be one of three formats:
+ // change: {first}[,{last}]c{first}[,{last}]
+ // append: {first}a{first}[,{last}]
+ // delete: {first}[,{last}]d{first}
+ p = line;
+ f1 = getdigits(&p);
+ if (*p == ',')
+ {
+ ++p;
+ l1 = getdigits(&p);
+ }
+ else
+ l1 = f1;
+ if (*p != 'a' && *p != 'c' && *p != 'd')
+ return FAIL; // invalid diff format
+ difftype = *p++;
+ f2 = getdigits(&p);
+ if (*p == ',')
+ {
+ ++p;
+ l2 = getdigits(&p);
+ }
+ else
+ l2 = f2;
+ if (l1 < f1 || l2 < f2)
+ return FAIL;
+
+ if (difftype == 'a')
+ {
+ *lnum_orig = f1 + 1;
+ *count_orig = 0;
+ }
+ else
+ {
+ *lnum_orig = f1;
+ *count_orig = l1 - f1 + 1;
+ }
+ if (difftype == 'd')
+ {
+ *lnum_new = f2 + 1;
+ *count_new = 0;
+ }
+ else
+ {
+ *lnum_new = f2;
+ *count_new = l2 - f2 + 1;
+ }
+ return OK;
+}
+
+/*
+ * Parses unified diff with zero(!) context lines.
+ * Return FAIL if there is no diff information in "line".
+ */
+ static int
+parse_diff_unified(
+ char_u *line,
+ linenr_T *lnum_orig,
+ long *count_orig,
+ linenr_T *lnum_new,
+ long *count_new)
+{
+ char_u *p;
+ long oldline, oldcount, newline, newcount;
+
+ // Parse unified diff hunk header:
+ // @@ -oldline,oldcount +newline,newcount @@
+ p = line;
+ if (*p++ == '@' && *p++ == '@' && *p++ == ' ' && *p++ == '-')
+ {
+ oldline = getdigits(&p);
+ if (*p == ',')
+ {
+ ++p;
+ oldcount = getdigits(&p);
+ }
+ else
+ oldcount = 1;
+ if (*p++ == ' ' && *p++ == '+')
+ {
+ newline = getdigits(&p);
+ if (*p == ',')
+ {
+ ++p;
+ newcount = getdigits(&p);
+ }
+ else
+ newcount = 1;
+ }
+ else
+ return FAIL; // invalid diff format
+
+ if (oldcount == 0)
+ oldline += 1;
+ if (newcount == 0)
+ newline += 1;
+ if (newline == 0)
+ newline = 1;
+
+ *lnum_orig = oldline;
+ *count_orig = oldcount;
+ *lnum_new = newline;
+ *count_new = newcount;
+
+ return OK;
+ }
+
+ return FAIL;
+}
+
+/*
+ * Callback function for the xdl_diff() function.
+ * Stores the diff output in a grow array.
+ */
+ static int
+xdiff_out(void *priv, mmbuffer_t *mb, int nbuf)
+{
+ diffout_T *dout = (diffout_T *)priv;
+ char_u *p;
+
+ // The header line always comes by itself, text lines in at least two
+ // parts. We drop the text part.
+ if (nbuf > 1)
+ return 0;
+
+ // sanity check
+ if (STRNCMP(mb[0].ptr, "@@ ", 3) != 0)
+ return 0;
+
+ if (ga_grow(&dout->dout_ga, 1) == FAIL)
+ return -1;
+ p = vim_strnsave((char_u *)mb[0].ptr, mb[0].size);
+ if (p == NULL)
+ return -1;
+ ((char_u **)dout->dout_ga.ga_data)[dout->dout_ga.ga_len++] = p;
+ return 0;
+}
+
+#endif /* FEAT_DIFF */