commit 8557edbfa8f74514de82feea4c62f5963e4e0aa7
author Hristo Venev <hristo@venev.name> Thu Apr 29 05:06:03 2021 +0300
committer GitHub <noreply@github.com> Thu Apr 29 11:06:03 2021 +0900
tree e18ba59b1b6e34ad6b9d7c3bb9c6662d51e599db
parent 69a733bda34d413d3ad545ef3132240e5d2a7c0c

bpo-24275: Don't downgrade unicode-only dicts to mixed on lookups (GH-25186)

Objects/dictobject.c

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 44796a6..0aeee70 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -857,7 +857,6 @@ lookdict_unicode(PyDictObject *mp, PyObject *key,
        unicodes is to override __eq__, and for speed we don't cater to
        that here. */
     if (!PyUnicode_CheckExact(key)) {
-        mp->ma_keys->dk_lookup = lookdict;
         return lookdict(mp, key, hash, value_addr);
     }
 
@@ -900,7 +899,6 @@ lookdict_unicode_nodummy(PyDictObject *mp, PyObject *key,
        unicodes is to override __eq__, and for speed we don't cater to
        that here. */
     if (!PyUnicode_CheckExact(key)) {
-        mp->ma_keys->dk_lookup = lookdict;
         return lookdict(mp, key, hash, value_addr);
     }
 
@@ -1084,7 +1082,6 @@ insertdict(PyDictObject *mp, PyObject *key, Py_hash_t hash, PyObject *value)
     if (ix == DKIX_ERROR)
         goto Fail;
 
-    assert(PyUnicode_CheckExact(key) || mp->ma_keys->dk_lookup == lookdict);
     MAINTAIN_TRACKING(mp, key, value);
 
     /* When insertion order is different from shared key, we can't share
@@ -1106,6 +1103,9 @@ insertdict(PyDictObject *mp, PyObject *key, Py_hash_t hash, PyObject *value)
             if (insertion_resize(mp) < 0)
                 goto Fail;
         }
+        if (!PyUnicode_CheckExact(key) && mp->ma_keys->dk_lookup != lookdict) {
+            mp->ma_keys->dk_lookup = lookdict;
+        }
         Py_ssize_t hashpos = find_empty_slot(mp->ma_keys, hash);
         ep = &DK_ENTRIES(mp->ma_keys)[mp->ma_keys->dk_nentries];
         dictkeys_set_index(mp->ma_keys, hashpos, mp->ma_keys->dk_nentries);
@@ -3068,6 +3068,9 @@ PyDict_SetDefault(PyObject *d, PyObject *key, PyObject *defaultobj)
                 return NULL;
             }
         }
+        if (!PyUnicode_CheckExact(key) && mp->ma_keys->dk_lookup != lookdict) {
+            mp->ma_keys->dk_lookup = lookdict;
+        }
         Py_ssize_t hashpos = find_empty_slot(mp->ma_keys, hash);
         ep0 = DK_ENTRIES(mp->ma_keys);
         ep = &ep0[mp->ma_keys->dk_nentries];