From: Eli Zaretskii <eliz@gnu.org>
Date: Mon, 15 Nov 2021 13:35:31 +0000 (+0200)
Subject: Avoid segfaults due to freed face cache
X-Git-Tag: emacs-28.0.90~70
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=5044151486cfd88edceb841d2bf8378dcc906e34;p=emacs.git

Avoid segfaults due to freed face cache

* src/xfaces.c (face_at_buffer_position): Make sure DEFAULT_FACE
is usable.  (Bug#51864)
---

diff --git a/src/xfaces.c b/src/xfaces.c
index 5e63e87d751..18e65d07e20 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -6423,7 +6423,10 @@ face_at_buffer_position (struct window *w, ptrdiff_t pos,
     else
       face_id = lookup_basic_face (w, f, DEFAULT_FACE_ID);
 
-    default_face = FACE_FROM_ID (f, face_id);
+    default_face = FACE_FROM_ID_OR_NULL (f, face_id);
+    if (!default_face)
+      default_face = FACE_FROM_ID (f,
+				   lookup_basic_face (w, f, DEFAULT_FACE_ID));
   }
 
   /* Optimize common cases where we can use the default face.  */