Add test for JSON encoder memory leak on recursion error

Author: okiemute04

Lib/test/test_json/test_recursion.py

@@ -1,5 +1,8 @@
 from test import support
 from test.test_json import PyTest, CTest
+import weakref
+import gc
+        
 
 
 class JSONTestObject:
@@ -114,7 +117,35 @@ def default(self, o):
         with self.assertRaises(RecursionError):
             with support.infinite_recursion(1000):
                 EndlessJSONEncoder(check_circular=False).encode(5j)
-
-
+    
+    @support.skip_if_unlimited_stack_size
+    @support.skip_emscripten_stack_overflow()
+    @support.skip_wasi_stack_overflow()
+    def test_memory_leak_on_recursion_error(self):
+        """Test that no memory leak occurs when a RecursionError is raised."""
+        weak_refs = []
+        class LeakTestObj:
+            pass
+        
+        def default(obj):
+            if isinstance(obj, LeakTestObj):
+                new_obj = LeakTestObj()
+                weak_refs.append(weakref.ref(new_obj))
+                return new_obj
+            raise TypeError
+        
+        
+        obj = LeakTestObj()
+        for _ in range(1000):
+            obj = [obj]
+        
+        with self.assertRaises(RecursionError):
+            self.dumps(obj, default=default)
+        
+        gc.collect()
+        for i, ref in enumerate(weak_refs):
+            self.assertIsNone(ref(),
+                f"Object {i} still alive - memory leak detected!")
+            
 class TestPyRecursion(TestRecursion, PyTest): pass
 class TestCRecursion(TestRecursion, CTest): pass