Fix image cache marking bug (Bug#6301).

* src/alloc.c (mark_terminals): Ensure that the image cache is marked
even if the terminal object was marked earlier (Bug#6301).

1 files changed, 6 insertions, 5 deletions

diff --git a/src/alloc.c b/src/alloc.c
index da63fe0f82b..4d19d3ac479 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -5771,13 +5771,14 @@ mark_terminals (void)
   for (t = terminal_list; t; t = t->next_terminal)
     {
       eassert (t->name != NULL);
-      if (!VECTOR_MARKED_P (t))
-        {
 #ifdef HAVE_WINDOW_SYSTEM
-          mark_image_cache (t->image_cache);
+      /* If a terminal object is reachable from a stacpro'ed object,
+         it might have been marked already.  Make sure the image cache
+         gets marked.  */
+      mark_image_cache (t->image_cache);
 #endif /* HAVE_WINDOW_SYSTEM */
-          mark_vectorlike ((struct Lisp_Vector *)t);
-        }
+      if (!VECTOR_MARKED_P (t))
+        mark_vectorlike ((struct Lisp_Vector *)t);
     }
 }