patch 9.0.1747: screenpos() may cause unnecessary redraw Commit: https://github.com/vim/vim/commit/6235a109c48ff2559eca3b16578c429ffb61eadc Author: zeertzjq <zeertzjq@outlook.com> Date: Sat Aug 19 14:12:42 2023 +0200 patch 9.0.1747: screenpos() may cause unnecessary redraw Problem: screenpos() may cause unnecessary redraw. Solution: Don't unnecessarily reset VALID_WROW flag. VALID_WROW flag is only used by two functions: validate_cursor() and cursor_valid(), and cursor_valid() is only used once in ex_sleep(). When adjust_plines_for_skipcol() was first added in patch 9.0.0640, it was called in two functions: comp_botline() and curs_rows(). - comp_botline() is called in two places: - onepage(), which resets VALID_WROW flag immediately afterwards. - validate_botline_win(), where resetting a VALID_ flag is strange. - curs_rows() is called in two places: - curs_columns(), which sets VALID_WROW flag afterwards. - validate_cline_row(), which is only used by GUI mouse focus. Therefore resetting VALID_WROW there doesn't seem to do anything useful. Also, a w_skipcol check (which resets VALID_WROW flag) was added to check_cursor_moved() in patch 9.0.0734, which seems to make more sense than resetting that flag in the middle of a computation. While at it make adjust_plines_for_skipcol() and textpos2screenpos() a bit less confusing: - Make adjust_plines_for_skipcol() return "off" instead of "n - off". - Use 0-based "row" in textpos2screenpos() until W_WINROW is added. closes: #12832 Signed-off-by: Christian Brabandt <cb@256bit.org> Co-authored-by: zeertzjq <zeertzjq@outlook.com>

--- a/src/drawscreen.c
+++ b/src/drawscreen.c
@@ -2343,7 +2343,7 @@ win_update(win_T *wp)
 			    {
 				int n = plines_win_nofill(wp, l, FALSE)
 								+ wp->w_topfill;
-				n = adjust_plines_for_skipcol(wp, n);
+				n -= adjust_plines_for_skipcol(wp);
 				if (n > wp->w_height)
 				    n = wp->w_height;
 				new_rows += n;