patch 8.1.1751: when redrawing popups plines_win() may be called often commit https://github.com/vim/vim/commit/9d5ffceb3fea247a88d4d3936e97b7f488aab6ff Author: Bram Moolenaar <Bram@vim.org> Date: Fri Jul 26 21:01:29 2019 +0200 patch 8.1.1751: when redrawing popups plines_win() may be called often Problem: When redrawing popups plines_win() may be called often. Solution: Pass a cache to mouse_comp_pos().

--- a/src/beval.c
+++ b/src/beval.c
@@ -43,7 +43,7 @@ find_word_under_cursor(
     {
 	// Found a window and the cursor is in the text.  Now find the line
 	// number.
-	if (!mouse_comp_pos(wp, &row, &col, &lnum))
+	if (!mouse_comp_pos(wp, &row, &col, &lnum, NULL))
 	{
 	    // Not past end of the file.
 	    lbuf = ml_get_buf(wp->w_buffer, lnum, FALSE);