gh-108314: Add PyDict_ContainsString() function (#108323)

1 files changed, 20 insertions, 14 deletions

diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index dc80291..ed9efca 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -5139,8 +5139,6 @@ static PyObject *
 Pointer_get_contents(CDataObject *self, void *closure)
 {
     StgDictObject *stgdict;
-    PyObject *keep, *ptr_probe;
-    CDataObject *ptr2ptr;
 
     if (*(void **)self->b_ptr == NULL) {
         PyErr_SetString(PyExc_ValueError,
@@ -5151,29 +5149,37 @@ Pointer_get_contents(CDataObject *self, void *closure)
     stgdict = PyObject_stgdict((PyObject *)self);
     assert(stgdict); /* Cannot be NULL for pointer instances */
 
-    keep = GetKeepedObjects(self);
+    PyObject *keep = GetKeepedObjects(self);
     if (keep != NULL) {
         // check if it's a pointer to a pointer:
         // pointers will have '0' key in the _objects
-        ptr_probe = PyDict_GetItemString(keep, "0");
-
-        if (ptr_probe != NULL) {
-            ptr2ptr = (CDataObject*) PyDict_GetItemString(keep, "1");
-            if (ptr2ptr ==  NULL) {
+        int ptr_probe = PyDict_ContainsString(keep, "0");
+        if (ptr_probe < 0) {
+            return NULL;
+        }
+        if (ptr_probe) {
+            PyObject *item;
+            if (PyDict_GetItemStringRef(keep, "1", &item) < 0) {
+                return NULL;
+            }
+            if (item == NULL) {
                 PyErr_SetString(PyExc_ValueError,
-                "Unexpected NULL pointer in _objects");
+                                "Unexpected NULL pointer in _objects");
                 return NULL;
             }
-            // don't construct a new object,
-            // return existing one instead to preserve refcount
+#ifndef NDEBUG
+            CDataObject *ptr2ptr = (CDataObject *)item;
+            // Don't construct a new object,
+            // return existing one instead to preserve refcount.
+            // Double-check that we are returning the same thing.
             assert(
                 *(void**) self->b_ptr == ptr2ptr->b_ptr ||
                 *(void**) self->b_value.c == ptr2ptr->b_ptr ||
                 *(void**) self->b_ptr == ptr2ptr->b_value.c ||
                 *(void**) self->b_value.c == ptr2ptr->b_value.c
-            ); // double-check that we are returning the same thing
-            Py_INCREF(ptr2ptr);
-            return (PyObject *) ptr2ptr;
+            );
+#endif
+            return item;
         }
     }