nextBTreeItems() and nextTreeSetItems(): unlike the other set iteration

"next" functions, these can return a PER_USE() error *after* decrefing
the keys and values left over from the last call.  But they don't mark
the iteration as terminated, so finiSetIteration() will also try to
decref the leftovers.  The fix is to mark the iteration as terminated
when these functions fail.

src/BTrees/BTreeItemsTemplate.c

@@ -12,7 +12,7 @@
 
  ****************************************************************************/
 
-#define BTREEITEMSTEMPLATE_C "$Id: BTreeItemsTemplate.c,v 1.11 2002/06/09 19:27:48 tim_one Exp $\n"
+#define BTREEITEMSTEMPLATE_C "$Id: BTreeItemsTemplate.c,v 1.12 2002/06/09 22:22:50 tim_one Exp $\n"
 
 typedef struct {
   PyObject_HEAD
@@ -514,8 +514,14 @@ nextBTreeItems(SetIteration *i)
           Bucket *currentbucket;
 
           currentbucket = BUCKET(ITEMS(i->set)->currentbucket);
-
-          UNLESS(PER_USE(currentbucket)) return -1;
+          UNLESS(PER_USE(currentbucket))
+            {
+              /* Mark iteration terminated, so that finiSetIteration doesn't
+               * try to redundantly decref the key and value
+               */
+              i->position = -1;
+              return -1;
+            }
 
           COPY_KEY(i->key, currentbucket->keys[ITEMS(i->set)->currentoffset]);
           INCREF_KEY(i->key);
@@ -555,8 +561,14 @@ nextTreeSetItems(SetIteration *i)
           Bucket *currentbucket;
 
           currentbucket = BUCKET(ITEMS(i->set)->currentbucket);
-
-          UNLESS(PER_USE(currentbucket)) return -1;
+          UNLESS(PER_USE(currentbucket))
+            {
+              /* Mark iteration terminated, so that finiSetIteration doesn't
+               * try to redundantly decref the key and value
+               */
+              i->position = -1;
+              return -1;
+            }
 
           COPY_KEY(i->key, currentbucket->keys[ITEMS(i->set)->currentoffset]);
           INCREF_KEY(i->key);