Fix a leak in RawJSON() when the argument is rejected

RawJSON_new allocated the object before parsing its argument and returned NULL without releasing it when the "U" check failed, so every RawJSON(<non-str>) leaked one object. Parse first and allocate second, as the other constructors in this file do, and check tp_alloc's result. Add a tracemalloc test in the shape of the existing ones: 1000 rejected calls leave 1001 extra allocations before this change and 0 after. Also fix the stub: RawJSON.value is the str that was passed, not a RawJSON. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
python-rapidjson · lelit · Sep 5, 2026 · Sep 3, 2026 · Sep 3, 2026 · 123396b10fd456c5d6585e98c3ef53f8d385459b
commit 123396b10fd456c5d6585e98c3ef53f8d385459b
diff --git a/rapidjson.cpp b/rapidjson.cpp
@@ -465,7 +465,6 @@ RawJSON_dealloc(RawJSON* self)
 static PyObject*
 RawJSON_new(PyTypeObject* type, PyObject* args, PyObject* kwds)
 {
-    PyObject* self = type->tp_alloc(type, 0);
     static char const* kwlist[] = {
         "value",
         NULL
@@ -475,6 +474,10 @@ RawJSON_new(PyTypeObject* type, PyObject* args, PyObject* kwds)
     if (!PyArg_ParseTupleAndKeywords(args, kwds, "U", (char**) kwlist, &value))
         return NULL;
 
+    PyObject* self = type->tp_alloc(type, 0);
+    if (self == NULL)
+        return NULL;
+
     ((RawJSON*) self)->value = value;
 
     Py_INCREF(value);

diff --git a/tests/test_memory_leaks.py b/tests/test_memory_leaks.py
@@ -125,3 +125,30 @@ def test_failed_validation():
     for stat in top_stats[:10]:
         # Uhm, with Py 3.14, on macOS,  the diff is 3...
         assert stat.count_diff <= 3
+
+
+def test_rejected_rawjson_value():
+    tracemalloc.start()
+
+    snapshot1 = tracemalloc.take_snapshot().filter_traces((
+        tracemalloc.Filter(True, __file__),))
+
+    # start the test
+    for j in range(1000):
+        try:
+            rj.RawJSON(j)
+        except TypeError:
+            pass
+
+    del j
+
+    gc.collect()
+
+    snapshot2 = tracemalloc.take_snapshot().filter_traces((
+        tracemalloc.Filter(True, __file__),))
+
+    top_stats = snapshot2.compare_to(snapshot1, 'lineno')
+    tracemalloc.stop()
+
+    for stat in top_stats[:10]:
+        assert stat.count_diff <= 3
diff --git a/typings/rapidjson/__init__.pyi b/typings/rapidjson/__init__.pyi
@@ -225,7 +225,7 @@ class Encoder:
 
 @t.final
 class RawJSON:
-    value: RawJSON
+    value: str
     def __new__(cls, value: str) -> RawJSON: ...