FIX: guard second usage of PyWeakref_GetObject (#934)

tacaswell · web-flow · commit bdb17aef93c6 · 2026-02-06T20:44:08.000-05:00
* FIX: guard second usage of PyWeakref_GetObject

This function was deprecated in 3.13 and will be removed in 3.15.  There
are two usages in pycurl, one in easy.c was already correctly guarded, the
other in share.c was not.

* MNT: Handle NULL / dead case in 3.13+ code path correctly

* MNT: further simplify handling the both old and new code paths

obj is only `None` in the &lt;3.13 code path if the weakref is dead.  Handle and
return early to simplify later code.

* MNT: let weakref errors propogate up and out
diff --git a/src/share.c b/src/share.c
@@ -262,29 +262,53 @@ share_cleanup_and_count_live_easies(CurlShareObject *self)
 
         if (it && to_remove) {
             PyObject *wr;
+            PyObject *obj = NULL;
 
             while ((wr = PyIter_Next(it))) {
-                PyObject *obj = PyWeakref_GetObject(wr);
+#if PY_VERSION_HEX >= 0x030D0000  /* Python 3.13+ */
+                int rc = PyWeakref_GetRef(wr, &obj);
+                // return -1 on error, 0 on dead object
+                // in either case, mark as removable and
+                // move to the next reference
+                if (rc < 0)  {
+                    Py_DECREF(wr);
+                    return -1;
+                } else if (rc == 0 || obj == NULL) {
+                    PyList_Append(to_remove, wr);
+                    Py_DECREF(wr);
+                    continue;
+                }
+
+#else
+                // will borrowed reference, None if object dead
+                obj = PyWeakref_GetObject(wr);
                 if (obj != Py_None) {
-                    CurlObject *easy = (CurlObject *)obj;
+                    // If not None, real object, INCREF and carry on
+                    Py_INCREF(obj);
+                } else {
+                    // otherwise mark for removal and move to the next ref
+                    PyList_Append(to_remove, wr);
+                    Py_DECREF(wr);
+                    continue;
+                }
+#endif
+                CurlObject *easy = (CurlObject *)obj;
 
-                    if (easy && easy->share == self) {
-                        if (self->detach_on_close) {
-                            curl_easy_setopt(easy->handle, CURLOPT_SHARE, NULL);
-                            easy->share = NULL;
+                if (easy && easy->share == self) {
+                    if (self->detach_on_close) {
+                        curl_easy_setopt(easy->handle, CURLOPT_SHARE, NULL);
+                        easy->share = NULL;
 
-                            PyList_Append(to_remove, wr);
-                        } else {
-                            has_live += 1;
-                        }
-                    } else {
                         PyList_Append(to_remove, wr);
+                    } else {
+                        has_live += 1;
                     }
                 } else {
                     PyList_Append(to_remove, wr);
                 }
 
                 Py_DECREF(wr);
+                Py_DECREF(obj);
             }
 
             Py_ssize_t i, n = PyList_GET_SIZE(to_remove);
@@ -329,6 +353,9 @@ do_share_close(CurlShareObject *self, PyObject *Py_UNUSED(ignored))
             (nlive == 1 ? "" : "s")
         );
         return NULL;
+    } else if (nlive < 0) {
+        // Error in share_cleanup_and_count_live_easies, propagate up
+        return NULL;
     }
 
     util_share_close(self);
