Mercurial > cpython-lru_cache-weakref

diff Modules/_collectionsmodule.c @ 67764:776c3c294bb7

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Issue #11004: Repair edge case in deque.count(). (Reviewed by Georg Brandl.) Also made similar changes to deque.reverse() though this wasn't strictly necessary (the edge case cannot occur with two pointers moving to meet in the middle). Making the change in reverse() was more a matter of future-proofing.
author Raymond Hettinger <python@rcn.com>
date Tue, 25 Jan 2011 21:32:39 +0000
parents a048d0cf2ad1
children 3c9232a684ae
line wrap: on
line diff
--- a/Modules/_collectionsmodule.c	Tue Jan 25 18:26:35 2011 +0000
+++ b/Modules/_collectionsmodule.c	Tue Jan 25 21:32:39 2011 +0000
@@ -485,7 +485,8 @@
         /* Advance left block/index pair */
         leftindex++;
         if (leftindex == BLOCKLEN) {
-            assert (leftblock->rightlink != NULL);
+            if (leftblock->rightlink == NULL)
+                break;
             leftblock = leftblock->rightlink;
             leftindex = 0;
         }
@@ -493,7 +494,8 @@
         /* Step backwards with the right block/index pair */
         rightindex--;
         if (rightindex == -1) {
-            assert (rightblock->leftlink != NULL);
+            if (rightblock->leftlink == NULL)
+                break;
             rightblock = rightblock->leftlink;
             rightindex = BLOCKLEN - 1;
         }
@@ -509,7 +511,7 @@
 {
     block *leftblock = deque->leftblock;
     Py_ssize_t leftindex = deque->leftindex;
-    Py_ssize_t n = (deque->len);
+    Py_ssize_t n = deque->len;
     Py_ssize_t i;
     Py_ssize_t count = 0;
     PyObject *item;
@@ -533,7 +535,8 @@
         /* Advance left block/index pair */
         leftindex++;
         if (leftindex == BLOCKLEN) {
-            assert (leftblock->rightlink != NULL);
+            if (leftblock->rightlink == NULL)  /* can occur when i==n-1 */
+                break;
             leftblock = leftblock->rightlink;
             leftindex = 0;
         }