bpo-41061: Fix incorrect expressions in hashtable (GH-21028)

Signed-off-by: Christian Heimes <christian@python.org>

Author: tiran

Misc/NEWS.d/next/Core and Builtins/2020-06-21-10-54-02.bpo-41061.AHf9MU.rst

@@ -0,0 +1 @@
+Fix incorrect expressions and asserts in hashtable code and tests.

Modules/_testinternalcapi.c

@@ -197,8 +197,8 @@ test_hashtable(PyObject *self, PyObject *Py_UNUSED(args))
     for (key='a'; key <= 'z'; key++) {
         _Py_hashtable_entry_t *entry = _Py_hashtable_get_entry(table, TO_PTR(key));
         assert(entry != NULL);
-        assert(entry->key = TO_PTR(key));
-        assert(entry->value = TO_PTR(VALUE(key)));
+        assert(entry->key == TO_PTR(key));
+        assert(entry->value == TO_PTR(VALUE(key)));
     }
 
     // Test _Py_hashtable_get()

Python/hashtable.c

@@ -133,7 +133,7 @@ _Py_hashtable_get_entry_generic(_Py_hashtable_t *ht, const void *key)
 {
     Py_uhash_t key_hash = ht->hash_func(key);
     size_t index = key_hash & (ht->nbuckets - 1);
-    _Py_hashtable_entry_t *entry = entry = TABLE_HEAD(ht, index);
+    _Py_hashtable_entry_t *entry = TABLE_HEAD(ht, index);
     while (1) {
         if (entry == NULL) {
             return NULL;
@@ -155,7 +155,7 @@ _Py_hashtable_get_entry_ptr(_Py_hashtable_t *ht, const void *key)
 {
     Py_uhash_t key_hash = _Py_hashtable_hash_ptr(key);
     size_t index = key_hash & (ht->nbuckets - 1);
-    _Py_hashtable_entry_t *entry = entry = TABLE_HEAD(ht, index);
+    _Py_hashtable_entry_t *entry = TABLE_HEAD(ht, index);
     while (1) {
         if (entry == NULL) {
             return NULL;