perf(redraw): only redraw Visual area when cursor has moved (#27340)

3 files changed, 17 insertions, 5 deletions

diff --git a/src/nvim/move.c b/src/nvim/move.c
index dd64a7ff2b..ea35813d21 100644
--- a/src/nvim/move.c
+++ b/src/nvim/move.c
@@ -147,6 +147,9 @@ static void redraw_for_cursorcolumn(win_T *wp)
       // When 'cursorcolumn' is set or "CurSearch" is in use
       // need to redraw with UPD_SOME_VALID.
       redraw_later(wp, UPD_SOME_VALID);
+    } else if (VIsual_active) {
+      // In Visual mode need to redraw with UPD_INVERTED.
+      redraw_later(wp, UPD_INVERTED);
     } else if (wp->w_p_cul && (wp->w_p_culopt_flags & CULOPT_SCRLINE)) {
       // When 'cursorlineopt' contains "screenline" need to redraw with UPD_VALID.
       redraw_later(wp, UPD_VALID);
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index 8c388b4318..9966e6129c 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -1347,10 +1347,6 @@ static void normal_redraw(NormalState *s)
 
   show_cursor_info_later(false);
 
-  if (VIsual_active) {
-    redraw_curbuf_later(UPD_INVERTED);  // update inverted part
-  }
-
   if (must_redraw) {
     update_screen();
   } else {
@@ -5129,6 +5125,7 @@ static void n_start_visual_mode(int c)
     curwin->w_old_cursor_lnum = curwin->w_cursor.lnum;
     curwin->w_old_visual_lnum = curwin->w_cursor.lnum;
   }
+  redraw_curbuf_later(UPD_VALID);
 }
 
 /// CTRL-W: Window commands
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index a4e69dd6b6..00e024e735 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -1541,7 +1541,15 @@ int expand_set_formatoptions(optexpand_T *args, int *numMatches, char ***matches
 /// The 'guicursor' option is changed.
 const char *did_set_guicursor(optset_T *args FUNC_ATTR_UNUSED)
 {
-  return parse_shape_opt(SHAPE_CURSOR);
+  const char *errmsg = parse_shape_opt(SHAPE_CURSOR);
+  if (errmsg != NULL) {
+    return errmsg;
+  }
+  if (VIsual_active) {
+    // In Visual mode cursor may be drawn differently.
+    redrawWinline(curwin, curwin->w_cursor.lnum);
+  }
+  return NULL;
 }
 
 /// The 'helpfile' option is changed.
@@ -1958,6 +1966,10 @@ const char *did_set_selection(optset_T *args FUNC_ATTR_UNUSED)
   if (*p_sel == NUL || check_opt_strings(p_sel, p_sel_values, false) != OK) {
     return e_invarg;
   }
+  if (VIsual_active) {
+    // In Visual mode cursor may be drawn differently.
+    redrawWinline(curwin, curwin->w_cursor.lnum);
+  }
   return NULL;
 }