Avoid division by zero crash observed by Yuan MEI.

[gnu-emacs] / src / dispnew.c

diff --git a/src/dispnew.c b/src/dispnew.c
index 91640769838f09a5e2636d29a82365aa1c434bcb..1a822f0636504e959b4c3fd0b5bdbfae76691ba6 100644 (file)
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -1694,7 +1694,8 @@ required_matrix_height (struct window *w)
 
   if (FRAME_WINDOW_P (f))
     {
-      int ch_height = FRAME_SMALLEST_FONT_HEIGHT (f);
+      /* http://lists.gnu.org/archive/html/emacs-devel/2015-11/msg00194.html  */
+      int ch_height = max (FRAME_SMALLEST_FONT_HEIGHT (f), 1);
       int window_pixel_height = window_box_height (w) + eabs (w->vscroll);
 
       return (((window_pixel_height + ch_height - 1)
@@ -1720,7 +1721,8 @@ required_matrix_width (struct window *w)
   struct frame *f = XFRAME (w->frame);
   if (FRAME_WINDOW_P (f))
     {
-      int ch_width = FRAME_SMALLEST_CHAR_WIDTH (f);
+      /* http://lists.gnu.org/archive/html/emacs-devel/2015-11/msg00194.html  */
+      int ch_width = max (FRAME_SMALLEST_CHAR_WIDTH (f), 1);
 
       /* Compute number of glyphs needed in a glyph row.  */
       return (((WINDOW_PIXEL_WIDTH (w) + ch_width - 1)