vim-patch:8.1.0822: peeking and flushing output slows down execution

Problem:    Peeking and flushing output slows down execution.
Solution:   Do not update the mode message when global_busy is set.  Do not
            flush when only peeking for a character. (Ken Takata)
https://github.com/vim/vim/commit/cb574f415486adff645ce384979bfecf27f5be8c

1 files changed, 17 insertions, 6 deletions

diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index afabbe6afc..b4b358052b 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -6557,6 +6557,21 @@ void grid_del_lines(ScreenGrid *grid, int row, int line_count, int end, int col,
   return;
 }
 
+// Return true when postponing displaying the mode message: when not redrawing
+// or inside a mapping.
+bool skip_showmode(void)
+{
+  // Call char_avail() only when we are going to show something, because it
+  // takes a bit of time.  redrawing() may also call char_avail_avail().
+  if (global_busy
+      || msg_silent != 0
+      || !redrawing()
+      || (char_avail() && !KeyTyped)) {
+    redraw_cmdline = true;  // show mode later
+    return true;
+  }
+  return false;
+}
 
 // Show the current mode and ruler.
 //
@@ -6588,12 +6603,8 @@ int showmode(void)
                  || restart_edit
                  || VIsual_active));
   if (do_mode || reg_recording != 0) {
-    // Don't show mode right now, when not redrawing or inside a mapping.
-    // Call char_avail() only when we are going to show something, because
-    // it takes a bit of time.
-    if (!redrawing() || (char_avail() && !KeyTyped) || msg_silent != 0) {
-      redraw_cmdline = TRUE;                    /* show mode later */
-      return 0;
+    if (skip_showmode()) {
+      return 0;  // show mode later
     }
 
     nwr_save = need_wait_return;