Update Python 3 to 3.13.13

commit_hash:526db1f6570443324e2690db042314848cd47d2e

1 files changed, 22 insertions, 4 deletions

diff --git a/contrib/tools/python3/Python/gc.c b/contrib/tools/python3/Python/gc.c
index d28cc41b20a..0397d8bad51 100644
--- a/contrib/tools/python3/Python/gc.c
+++ b/contrib/tools/python3/Python/gc.c
@@ -749,7 +749,7 @@ move_legacy_finalizer_reachable(PyGC_Head *finalizers)
  * no object in `unreachable` is weakly referenced anymore.
  */
 static int
-handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old)
+handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old, bool allow_callbacks)
 {
     PyGC_Head *gc;
     PyObject *op;               /* generally FROM_GC(gc) */
@@ -758,7 +758,9 @@ handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old)
     PyGC_Head *next;
     int num_freed = 0;
 
-    gc_list_init(&wrcb_to_call);
+    if (allow_callbacks) {
+        gc_list_init(&wrcb_to_call);
+    }
 
     /* Clear all weakrefs to the objects in unreachable.  If such a weakref
      * also has a callback, move it into `wrcb_to_call` if the callback
@@ -814,6 +816,11 @@ handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old)
             _PyObject_ASSERT((PyObject *)wr, wr->wr_object == op);
             _PyWeakref_ClearRef(wr);
             _PyObject_ASSERT((PyObject *)wr, wr->wr_object == Py_None);
+
+            if (!allow_callbacks) {
+                continue;
+            }
+
             if (wr->wr_callback == NULL) {
                 /* no callback */
                 continue;
@@ -866,6 +873,10 @@ handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old)
         }
     }
 
+    if (!allow_callbacks) {
+        return 0;
+    }
+
     /* Invoke the callbacks we decided to honor.  It's safe to invoke them
      * because they can't reference unreachable objects.
      */
@@ -1401,8 +1412,7 @@ gc_collect_main(PyThreadState *tstate, int generation, _PyGC_Reason reason)
     }
 
     /* Clear weakrefs and invoke callbacks as necessary. */
-    m += handle_weakrefs(&unreachable, old);
-
+    m += handle_weakrefs(&unreachable, old, true);
     validate_list(old, collecting_clear_unreachable_clear);
     validate_list(&unreachable, collecting_set_unreachable_clear);
 
@@ -1415,6 +1425,14 @@ gc_collect_main(PyThreadState *tstate, int generation, _PyGC_Reason reason)
     PyGC_Head final_unreachable;
     handle_resurrected_objects(&unreachable, &final_unreachable, old);
 
+    /* Clear weakrefs to objects in the unreachable set.  No Python-level
+     * code must be allowed to access those unreachable objects.  During
+     * delete_garbage(), finalizers outside the unreachable set might run
+     * and create new weakrefs.  If those weakrefs were not cleared, they
+     * could reveal unreachable objects.  Callbacks are not executed.
+     */
+    handle_weakrefs(&final_unreachable, NULL, false);
+
     /* Call tp_clear on objects in the final_unreachable set.  This will cause
     * the reference cycles to be broken.  It may also cause some objects
     * in finalizers to be freed.