Correctly cache images when frames vary in their font metrics

* src/alloc.c (mark_frame): Mark this frame's image cache, if it
exist.
(mark_terminals): Cease marking T->image_cache.

* src/androidfns.c (unwind_create_frame, Fx_create_frame)
(android_create_tip_frame):

* src/haikufns.c (unwind_create_frame, haiku_create_frame)
(haiku_create_tip_frame):

* src/nsfns.m (unwind_create_frame):

* src/pgtkfns.c (unwind_create_frame, Fx_create_frame)
(x_create_tip_frame):

* src/xfns.c (unwind_create_frame, Fx_create_frame)
(x_create_tip_frame):

* src/w32fns.c (unwind_create_frame, Fx_create_frame)
(w32_create_tip_frame): Remove adjustments of the frame image
cache's reference count rendered redundant by the assignment of
image caches to individual frames rather than terminals.

* src/dispextern.h (struct image_cache) <scaling_col_width>: New
field.

* src/frame.c (gui_set_font): In lieu of clearing F's image
cache unconditionally, establish whether the column width as
considered by compute_image_size has changed, and if so, adjust
or reassign the frame's image cache.
(make_frame): Clear F->image_cache.

* src/frame.h (struct frame) <image_cache>: New field.
(FRAME_IMAGE_CACHE): Return F->image_cache.

* src/image.c (make_image_cache): Clear C->scaling_col_width.
(cache_image): Adjust to new means of assigning image caches to
frames.

* src/termhooks.h (struct terminal) <image_cache>: Delete field.

* src/xfaces.c (init_frame_faces): Do image cache assignment
with all new frames.

1 files changed, 7 insertions, 6 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 9304e4e42bb..666f77bfce1 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -7055,6 +7055,13 @@ mark_frame (struct Lisp_Vector *ptr)
   for (tem = f->conversion.actions; tem; tem = tem->next)
     mark_object (tem->data);
 #endif
+
+#ifdef HAVE_WINDOW_SYSTEM
+  /* Mark this frame's image cache, though it might be common to several
+     frames with the same font size.  */
+  if (FRAME_IMAGE_CACHE (f))
+    mark_image_cache (FRAME_IMAGE_CACHE (f));
+#endif /* HAVE_WINDOW_SYSTEM */
 }
 
 static void
@@ -7515,12 +7522,6 @@ mark_terminals (void)
   for (t = terminal_list; t; t = t->next_terminal)
     {
       eassert (t->name != NULL);
-#ifdef HAVE_WINDOW_SYSTEM
-      /* 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 */
       if (!vectorlike_marked_p (&t->header))
         mark_vectorlike (&t->header);
     }