=== modified file 'src/buffer.c'
--- src/buffer.c	2012-09-06 09:15:44 +0000
+++ src/buffer.c	2012-09-07 07:27:44 +0000
@@ -1700,6 +1700,19 @@
     }
 }
 
+/* Set all B's Lisp_Object slots to nil in
+   attempt to let GC to sweep them early.  */
+
+static inline void
+nullify_buffer (struct buffer *b)
+{
+  int offset;
+
+  FOR_EACH_PER_BUFFER_OBJECT_AT (offset)
+    set_per_buffer_value (b, offset, Qnil);
+  bset_undo_list (b, Qnil);
+}
+
 DEFUN ("kill-buffer", Fkill_buffer, Skill_buffer, 0, 1, "bKill buffer: ",
        doc: /* Kill the buffer specified by BUFFER-OR-NAME.
 The argument may be a buffer or the name of an existing buffer.
@@ -1911,14 +1924,11 @@
       /* Perhaps we should explicitly free the interval tree here... */
     }
 
-  /* Reset the local variables, so that this buffer's local values
-     won't be protected from GC.  They would be protected
-     if they happened to remain cached in their symbols.
-     This gets rid of them for certain.  */
+  /* Get rid of local bindings.  */
   swap_out_buffer_local_variables (b);
-  reset_buffer_local_variables (b, 1);
 
-  bset_name (b, Qnil);
+  /* B is really dead after this.  */
+  nullify_buffer (b);
 
   BLOCK_INPUT;
   if (b->base_buffer)
@@ -1942,9 +1952,7 @@
       free_region_cache (b->width_run_cache);
       b->width_run_cache = 0;
     }
-  bset_width_table (b, Qnil);
   UNBLOCK_INPUT;
-  bset_undo_list (b, Qnil);
 
   /* Run buffer-list-update-hook.  */
   if (!NILP (Vrun_hooks))

=== modified file 'src/frame.c'
--- src/frame.c	2012-09-04 17:34:54 +0000
+++ src/frame.c	2012-09-07 07:13:54 +0000
@@ -1114,6 +1114,20 @@
   return 0;
 }
 
+/* Set all F's Lisp_Object slots to nil in attempt to let
+   GC to sweep them early.  Setting f->terminal to NULL
+   makes FRAME_LIVE_P false for this frame.  */
+
+static inline void
+nullify_frame (struct frame *f)
+{
+  Lisp_Object *ptr;
+
+  for (ptr = &f->name; ptr <= &f->current_tool_bar_string; ptr++)
+    *ptr = Qnil;
+  f->terminal = NULL;
+}
+
 /* Delete FRAME.  When FORCE equals Qnoelisp, delete FRAME
   unconditionally.  x_connection_closed and delete_terminal use
   this.  Any other value of FORCE implements the semantics
@@ -1321,7 +1335,9 @@
   {
     struct terminal *terminal = FRAME_TERMINAL (f);
     f->output_data.nothing = 0;
-    f->terminal = 0;             /* Now the frame is dead. */
+
+    /* F is really dead after this.  */
+    nullify_frame (f);
 
     /* If needed, delete the terminal that this frame was on.
        (This must be done after the frame is killed.) */