Issue 11004: Fix edge case for deque.count().
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index c140e97..faa2577 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -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;
}