From: Eli Zaretskii <eliz@gnu.org>
Date: Thu, 25 May 2023 17:50:46 +0000 (+0300)
Subject: Fix rare crashes in 'try_window_reusing_current_matrix'
X-Git-Tag: emacs-29.0.92~100
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=d292d282292b8ce1f4e1ba97d0110178153f73c5;p=emacs.git

Fix rare crashes in 'try_window_reusing_current_matrix'

* src/xdisp.c (try_window_reusing_current_matrix): Make sure we
never use a mode-line glyph row to start displaying scrolled-in
rows.  (Bug#63711)
---

diff --git a/src/xdisp.c b/src/xdisp.c
index aeba47e4c16..2ddfdf0d51b 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -21081,8 +21081,10 @@ try_window_reusing_current_matrix (struct window *w)
 	    pt_row = first_row_to_display;
 	}
 
+      if (first_row_to_display->y >= yb)
+	return false;
+
       /* Start displaying at the start of first_row_to_display.  */
-      eassert (first_row_to_display->y < yb);
       init_to_row_start (&it, w, first_row_to_display);
 
       nrows_scrolled = (MATRIX_ROW_VPOS (first_reusable_row, w->current_matrix)