Issue #13018: Fix reference leaks in error paths in dictobject.c.
Patch by Suman Saha.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 3fa5cc4..79894e5 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1314,14 +1314,18 @@
         PyObject *key;
         Py_hash_t hash;
 
-        if (dictresize(mp, Py_SIZE(seq)))
+        if (dictresize(mp, Py_SIZE(seq))) {
+            Py_DECREF(d);
             return NULL;
+        }
 
         while (_PyDict_Next(seq, &pos, &key, &oldvalue, &hash)) {
             Py_INCREF(key);
             Py_INCREF(value);
-            if (insertdict(mp, key, hash, value))
+            if (insertdict(mp, key, hash, value)) {
+                Py_DECREF(d);
                 return NULL;
+            }
         }
         return d;
     }
@@ -1332,14 +1336,18 @@
         PyObject *key;
         Py_hash_t hash;
 
-        if (dictresize(mp, PySet_GET_SIZE(seq)))
+        if (dictresize(mp, PySet_GET_SIZE(seq))) {
+            Py_DECREF(d);
             return NULL;
+        }
 
         while (_PySet_NextEntry(seq, &pos, &key, &hash)) {
             Py_INCREF(key);
             Py_INCREF(value);
-            if (insertdict(mp, key, hash, value))
+            if (insertdict(mp, key, hash, value)) {
+                Py_DECREF(d);
                 return NULL;
+            }
         }
         return d;
     }