Perform font-specific cleanup when font object is swept by GC. See

http://lists.gnu.org/archive/html/emacs-devel/2013-10/msg00740.html.
* alloc.c (cleanup_vector): New function.
(sweep_vector): Call it for each reclaimed vector object.
* font.h (struct font): Adjust comment.

src/ChangeLog

@@ -9,9 +9,15 @@
 	* nsfont.m (nsfont_close):
 	* w32font.c (w32font_close):
 	* xfont.c (xfont_close):
-	* xftfont.c (xftfont_close): Adjust driver-specific close
-	functions, tweak comments and make functions safe if called
-	more than once for the same font object.
+	* xftfont.c (xftfont_close): Adjust driver-specific close functions,
+	tweak comments and make functions safe if called more than once for
+	the same font object.
+
+	Perform font-specific cleanup when font object is swept by GC.  See
+	http://lists.gnu.org/archive/html/emacs-devel/2013-10/msg00740.html.
+	* alloc.c (cleanup_vector): New function.
+	(sweep_vector): Call it for each reclaimed vector object.
+	* font.h (struct font): Adjust comment.
 
 2013-10-24  Glenn Morris  <rgm@gnu.org>
 

src/alloc.c

@@ -2837,6 +2837,19 @@ vector_nbytes (struct Lisp_Vector *v)
   return vroundup (size);
 }
 
+/* Release extra resources still in use by VECTOR, which may be any
+   vector-like object.  For now, this is used just to free data in
+   font objects.  */
+
+static void
+cleanup_vector (struct Lisp_Vector *vector)
+{
+  if (PSEUDOVECTOR_TYPEP (&vector->header, PVEC_FONT)
+      && ((vector->header.size & PSEUDOVECTOR_SIZE_MASK)
+	  == FONT_OBJECT_MAX))
+    ((struct font *) vector)->driver->close ((struct font *) vector);
+}
+
 /* Reclaim space used by unmarked vectors.  */
 
 static void
@@ -2871,6 +2884,7 @@ sweep_vectors (void)
 	    {
 	      ptrdiff_t total_bytes;
 
+	      cleanup_vector (vector);
 	      nbytes = vector_nbytes (vector);
 	      total_bytes = nbytes;
 	      next = ADVANCE (vector, nbytes);
@@ -2882,6 +2896,7 @@ sweep_vectors (void)
 		{
 		  if (VECTOR_MARKED_P (next))
 		    break;
+		  cleanup_vector (next);
 		  nbytes = vector_nbytes (next);
 		  total_bytes += nbytes;
 		  next = ADVANCE (next, nbytes);

src/font.h

@@ -545,7 +545,7 @@ struct font_driver
   Lisp_Object (*open) (struct frame *f, Lisp_Object font_entity,
                        int pixel_size);
 
-  /* Close FONT.  */
+  /* Close FONT.  NOTE: this can be called by GC.  */
   void (*close) (struct font *font);
 
   /* Optional (if FACE->extra is not used).