vim-patch:8.1.2214: too much is redrawn when 'cursorline' is set

Problem:    Too much is redrawn when 'cursorline' is set.
Solution:   Don't do a complete redraw. (closes vim/vim#5079)
https://github.com/vim/vim/commit/11a58af66fa5c442f0a22c5d59beabf187ed4e89

1 files changed, 8 insertions, 14 deletions

diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index 1471c16a9f..54ca216a53 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -1275,25 +1275,19 @@ static void normal_redraw(NormalState *s)
     redrawWinline(curwin, curwin->w_cursor.lnum);
   }
 
-  if (curwin->w_p_cul && curwin->w_p_wrap
-      && (curwin->w_p_culopt_flags & CULOPT_SCRLINE)) {
-    must_redraw = NOT_VALID;
+  // Might need to update for 'cursorline'.
+  // When 'cursorlineopt' is "screenline" need to redraw always.
+  if (curwin->w_p_cul
+      && (curwin->w_last_cursorline != curwin->w_cursor.lnum
+          || (curwin->w_p_culopt_flags & CULOPT_SCRLINE))
+      && !char_avail()) {
+    redraw_later(curwin, VALID);
   }
 
   if (VIsual_active) {
     update_curbuf(INVERTED);  // update inverted part
   } else if (must_redraw) {
-    // Might need some more update for the cursorscreen line.
-    // TODO(vim): can we optimized this?
-    if (curwin->w_p_cul
-        && curwin->w_p_wrap
-        && (curwin->w_p_culopt_flags & CULOPT_SCRLINE)
-        && !char_avail()) {
-      update_screen(VALID);
-    }
-    else {
-      update_screen(0);
-    }
+    update_screen(0);
   } else if (redraw_cmdline || clear_cmdline) {
     showmode();
   }