patch 8.1.1922: in diff mode global operations can be very slow Commit: https://github.com/vim/vim/commit/4f57eefe1e84b5a90e08474092ea6fc8825ad5c9 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Aug 24 20:54:19 2019 +0200 patch 8.1.1922: in diff mode global operations can be very slow Problem: In diff mode global operations can be very slow. Solution: Do not call diff_redraw() many times, call it once when redrawing. And also don't update folds multiple times.

--- a/src/fold.c
+++ b/src/fold.c
@@ -813,6 +813,11 @@ foldUpdate(win_T *wp, linenr_T top, line
 
     if (disable_fold_update > 0)
 	return;
+#ifdef FEAT_DIFF
+    if (need_diff_redraw)
+	// will update later
+	return;
+#endif
 
     /* Mark all folds from top to bot as maybe-small. */
     (void)foldFind(&wp->w_folds, top, &fp);