Avoid crashes in redisplay due to problematic font setups

* src/xdisp.c (handle_single_display_spec)
(produce_stretch_glyph): Avoid crashes if a face's font is NULL.
(Bug#75725)

1 files changed, 5 insertions, 2 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 19ce5b74b01..f11a8aa6d55 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -6111,7 +6111,9 @@ handle_single_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
             {
               struct face *face = FACE_FROM_ID (it->f, it->face_id);
               it->voffset = - (XFLOATINT (value)
-                               * (normal_char_height (face->font, -1)));
+                               * (face->font
+                                  ? normal_char_height (face->font, -1)
+                                  : FRAME_LINE_HEIGHT (it->f)));
             }
 #endif /* HAVE_WINDOW_SYSTEM */
         }
@@ -32056,7 +32058,8 @@ produce_stretch_glyph (struct it *it)
   /* Compute height.  */
   if (FRAME_WINDOW_P (it->f))
     {
-      int default_height = normal_char_height (font, ' ');
+      int default_height =
+        font ? normal_char_height (font, ' ') : FRAME_LINE_HEIGHT (it->f);
 
       if ((prop = plist_get (plist, QCheight), !NILP (prop))
           && calc_pixel_width_or_height (&tem, it, prop, font, false, NULL))