(sweep_weak_table): Mark only objects that are not

marked already.

2 files changed, 21 insertions, 7 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 9e30bff4191..1bc2bf0b8bb 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,8 @@
 2000-07-03  Gerd Moellmann  <gerd@gnu.org>
 
+        * fns.c (sweep_weak_table): Mark only objects that are not 
+        marked already.
+
         * frame.c (next_frame, prev_frame): If MINIBUF is a window,
         include those frames as candidates which have their focus
         redirected to the minibuffer frame.
diff --git a/src/fns.c b/src/fns.c
index 24107f2ddeb..680fec8cc62 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -4175,14 +4175,17 @@ sweep_weak_table (h, remove_entries_p)
           int remove_p;
           int i = XFASTINT (idx);
           Lisp_Object next;
+          int key_known_to_survive_p, value_known_to_survive_p;
 
+          key_known_to_survive_p = survives_gc_p (HASH_KEY (h, i));
+          value_known_to_survive_p = survives_gc_p (HASH_VALUE (h, i));
+          
           if (EQ (h->weak, Qkey))
-            remove_p = !survives_gc_p (HASH_KEY (h, i));
+            remove_p = !key_known_to_survive_p;
           else if (EQ (h->weak, Qvalue))
-            remove_p = !survives_gc_p (HASH_VALUE (h, i));
+            remove_p = !value_known_to_survive_p;
           else if (EQ (h->weak, Qt))
-            remove_p = (!survives_gc_p (HASH_KEY (h, i))
-                        || !survives_gc_p (HASH_VALUE (h, i)));
+            remove_p = !key_known_to_survive_p || !value_known_to_survive_p;
           else
             abort ();
                       
@@ -4214,9 +4217,17 @@ sweep_weak_table (h, remove_entries_p)
               if (!remove_p)
                 {
                   /* Make sure key and value survive.  */
-                  mark_object (&HASH_KEY (h, i));
-                  mark_object (&HASH_VALUE (h, i));
-                  marked = 1;
+                  if (!key_known_to_survive_p)
+                    {
+                      mark_object (&HASH_KEY (h, i));
+                      marked = 1;
+                    }
+
+                  if (!value_known_to_survive_p)
+                    {
+                      mark_object (&HASH_VALUE (h, i));
+                      marked = 1;
+                    }
                 }
             }