vim-patch:9.1.1136: Match highlighting marks a buffer region as changed (#32561)

Problem:  Match highlighting marks a buffer region to be redrawn as if
          its buffer text was changed, unnecessarily invoking syntax code.
Solution: Set the `w_redraw_top/bot` variables instead of the b_mod_* ones
          (Luuk van Baal)

https://github.com/vim/vim/commit/7bbb0f357e9f9d3a737dac75e4b5ba7dfbf3ecc1

3 files changed, 31 insertions, 61 deletions

diff --git a/src/nvim/drawscreen.c b/src/nvim/drawscreen.c
index 4d7f80bf76..162bcb910b 100644
--- a/src/nvim/drawscreen.c
+++ b/src/nvim/drawscreen.c
@@ -2695,18 +2695,36 @@ void redraw_buf_line_later(buf_T *buf, linenr_T line, bool force)
   }
 }
 
-void redraw_buf_range_later(buf_T *buf, linenr_T firstline, linenr_T lastline)
+void redraw_win_range_later(win_T *wp, linenr_T first, linenr_T last)
+{
+  if (last >= wp->w_topline && first < wp->w_botline) {
+    if (wp->w_redraw_top == 0 || wp->w_redraw_top > first) {
+      wp->w_redraw_top = first;
+    }
+    if (wp->w_redraw_bot == 0 || wp->w_redraw_bot < last) {
+      wp->w_redraw_bot = last;
+    }
+    redraw_later(wp, UPD_VALID);
+  }
+}
+
+/// Changed something in the current window, at buffer line "lnum", that
+/// requires that line and possibly other lines to be redrawn.
+/// Used when entering/leaving Insert mode with the cursor on a folded line.
+/// Used to remove the "$" from a change command.
+/// Note that when also inserting/deleting lines w_redraw_top and w_redraw_bot
+/// may become invalid and the whole window will have to be redrawn.
+void redrawWinline(win_T *wp, linenr_T lnum)
+  FUNC_ATTR_NONNULL_ALL
+{
+  redraw_win_range_later(wp, lnum, lnum);
+}
+
+void redraw_buf_range_later(buf_T *buf, linenr_T first, linenr_T last)
 {
   FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
-    if (wp->w_buffer == buf
-        && lastline >= wp->w_topline && firstline < wp->w_botline) {
-      if (wp->w_redraw_top == 0 || wp->w_redraw_top > firstline) {
-        wp->w_redraw_top = firstline;
-      }
-      if (wp->w_redraw_bot == 0 || wp->w_redraw_bot < lastline) {
-        wp->w_redraw_bot = lastline;
-      }
-      redraw_later(wp, UPD_VALID);
+    if (wp->w_buffer == buf) {
+      redraw_win_range_later(wp, first, last);
     }
   }
 }
@@ -2805,27 +2823,6 @@ void win_redraw_last_status(const frame_T *frp)
   }
 }
 
-/// Changed something in the current window, at buffer line "lnum", that
-/// requires that line and possibly other lines to be redrawn.
-/// Used when entering/leaving Insert mode with the cursor on a folded line.
-/// Used to remove the "$" from a change command.
-/// Note that when also inserting/deleting lines w_redraw_top and w_redraw_bot
-/// may become invalid and the whole window will have to be redrawn.
-void redrawWinline(win_T *wp, linenr_T lnum)
-  FUNC_ATTR_NONNULL_ALL
-{
-  if (lnum >= wp->w_topline
-      && lnum < wp->w_botline) {
-    if (wp->w_redraw_top == 0 || wp->w_redraw_top > lnum) {
-      wp->w_redraw_top = lnum;
-    }
-    if (wp->w_redraw_bot == 0 || wp->w_redraw_bot < lnum) {
-      wp->w_redraw_bot = lnum;
-    }
-    redraw_later(wp, UPD_VALID);
-  }
-}
-
 /// Return true if the cursor line in window "wp" may be concealed, according
 /// to the 'concealcursor' option.
 bool conceal_cursor_line(const win_T *wp)
diff --git a/src/nvim/fold.c b/src/nvim/fold.c
index b59933d600..45cc327444 100644
--- a/src/nvim/fold.c
+++ b/src/nvim/fold.c
@@ -2098,10 +2098,7 @@ static void foldUpdateIEMS(win_T *const wp, linenr_T top, linenr_T bot)
   // this in other situations, the changed lines will be redrawn anyway and
   // this method can cause the whole window to be updated.
   if (end != bot) {
-    if (wp->w_redraw_top == 0 || wp->w_redraw_top > top) {
-      wp->w_redraw_top = top;
-    }
-    wp->w_redraw_bot = MAX(wp->w_redraw_bot, end);
+    redraw_win_range_later(wp, top, end);
   }
 
   invalid_top = 0;
diff --git a/src/nvim/match.c b/src/nvim/match.c
index 86cab5221d..a1126fbbcd 100644
--- a/src/nvim/match.c
+++ b/src/nvim/match.c
@@ -190,19 +190,7 @@ static int match_add(win_T *wp, const char *const grp, const char *const pat, in
 
     // Calculate top and bottom lines for redrawing area
     if (toplnum != 0) {
-      if (wp->w_buffer->b_mod_set) {
-        if (wp->w_buffer->b_mod_top > toplnum) {
-          wp->w_buffer->b_mod_top = toplnum;
-        }
-        if (wp->w_buffer->b_mod_bot < botlnum) {
-          wp->w_buffer->b_mod_bot = botlnum;
-        }
-      } else {
-        wp->w_buffer->b_mod_set = true;
-        wp->w_buffer->b_mod_top = toplnum;
-        wp->w_buffer->b_mod_bot = botlnum;
-        wp->w_buffer->b_mod_xlines = 0;
-      }
+      redraw_win_range_later(wp, toplnum, botlnum);
       m->mit_toplnum = toplnum;
       m->mit_botlnum = botlnum;
       rtype = UPD_VALID;
@@ -268,19 +256,7 @@ static int match_delete(win_T *wp, int id, bool perr)
   vim_regfree(cur->mit_match.regprog);
   xfree(cur->mit_pattern);
   if (cur->mit_toplnum != 0) {
-    if (wp->w_buffer->b_mod_set) {
-      if (wp->w_buffer->b_mod_top > cur->mit_toplnum) {
-        wp->w_buffer->b_mod_top = cur->mit_toplnum;
-      }
-      if (wp->w_buffer->b_mod_bot < cur->mit_botlnum) {
-        wp->w_buffer->b_mod_bot = cur->mit_botlnum;
-      }
-    } else {
-      wp->w_buffer->b_mod_set = true;
-      wp->w_buffer->b_mod_top = cur->mit_toplnum;
-      wp->w_buffer->b_mod_bot = cur->mit_botlnum;
-      wp->w_buffer->b_mod_xlines = 0;
-    }
+    redraw_win_range_later(wp, cur->mit_toplnum, cur->mit_botlnum);
     rtype = UPD_VALID;
   }
   xfree(cur->mit_pos_array);