Issue #28509: dict.update() no longer allocate unnecessary large memory
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 03c973b..9f98f68 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -2406,9 +2406,11 @@
* incrementally resizing as we insert new items. Expect
* that there will be no (or few) overlapping keys.
*/
- if (mp->ma_keys->dk_usable * 3 < other->ma_used * 2)
- if (dictresize(mp, (mp->ma_used + other->ma_used)*2) != 0)
+ if (USABLE_FRACTION(mp->ma_keys->dk_size) < other->ma_used) {
+ if (dictresize(mp, ESTIMATE_SIZE(mp->ma_used + other->ma_used))) {
return -1;
+ }
+ }
ep0 = DK_ENTRIES(other->ma_keys);
for (i = 0, n = other->ma_keys->dk_nentries; i < n; i++) {
PyObject *key, *value;