Revert "clear weakrefs unconditionally in extension modules"

This reverts commit 9024079.

Author: xuantengh

Modules/_collectionsmodule.c

@@ -1532,7 +1532,9 @@ deque_dealloc(PyObject *self)
     Py_ssize_t i;
 
     PyObject_GC_UnTrack(deque);
-    PyObject_ClearWeakRefs(self);
+    if (deque->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(self);
+    }
     if (deque->leftblock != NULL) {
         (void)deque_clear(self);
         assert(deque->leftblock != NULL);

Modules/_elementtree.c

@@ -690,7 +690,8 @@ element_dealloc(PyObject *op)
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(self);
 
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
 
     /* element_gc_clear clears all references and deallocates extra
     */

Modules/_functoolsmodule.c

@@ -351,7 +351,9 @@ partial_dealloc(PyObject *self)
     PyTypeObject *tp = Py_TYPE(self);
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(self);
-    PyObject_ClearWeakRefs(self);
+    if (partialobject_CAST(self)->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(self);
+    }
     (void)partial_clear(self);
     tp->tp_free(self);
     Py_DECREF(tp);
@@ -1619,7 +1621,9 @@ lru_cache_dealloc(PyObject *op)
     PyTypeObject *tp = Py_TYPE(obj);
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(obj);
-    PyObject_ClearWeakRefs(op);
+    if (obj->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
 
     (void)lru_cache_tp_clear(op);
     tp->tp_free(obj);

Modules/_io/bufferedio.c

@@ -421,7 +421,8 @@ buffered_dealloc(PyObject *op)
         return;
     _PyObject_GC_UNTRACK(self);
     self->ok = 0;
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     if (self->buffer) {
         PyMem_Free(self->buffer);
         self->buffer = NULL;

Modules/_io/fileio.c

@@ -570,7 +570,9 @@ fileio_dealloc(PyObject *op)
         PyMem_Free(self->stat_atopen);
         self->stat_atopen = NULL;
     }
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     (void)fileio_clear(op);
 
     PyTypeObject *tp = Py_TYPE(op);

Modules/_io/iobase.c

@@ -383,7 +383,8 @@ iobase_dealloc(PyObject *op)
     }
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     Py_CLEAR(self->dict);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_io/textio.c

@@ -1469,7 +1469,8 @@ textiowrapper_dealloc(PyObject *op)
         return;
     self->ok = 0;
     _PyObject_GC_UNTRACK(self);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     (void)textiowrapper_clear(op);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_io/winconsoleio.c

@@ -518,7 +518,8 @@ winconsoleio_dealloc(PyObject *op)
     if (_PyIOBase_finalize(op) < 0)
         return;
     _PyObject_GC_UNTRACK(self);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     Py_CLEAR(self->dict);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_queuemodule.c

@@ -221,7 +221,9 @@ simplequeue_dealloc(PyObject *op)
 
     PyObject_GC_UnTrack(self);
     (void)simplequeue_clear(op);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     tp->tp_free(self);
     Py_DECREF(tp);
 }

Modules/_sqlite/blob.c

@@ -56,7 +56,9 @@ blob_dealloc(PyObject *op)
 
     close_blob(self);
 
-    PyObject_ClearWeakRefs(op);
+    if (self->in_weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     (void)tp->tp_clear(op);
     tp->tp_free(self);
     Py_DECREF(tp);