Issue #26718: super.__init__ no longer leaks memory if called multiple times.

serhiy-storchaka · serhiy-storchaka · commit 3d7497608ba8 · 2016-04-13T15:27:33.000+03:00
NOTE: A direct call of super.__init__ is not endorsed!
diff --git a/Lib/test/test_super.py b/Lib/test/test_super.py
@@ -171,6 +171,15 @@ def g():
         c = f().__closure__[0]
         self.assertRaises(TypeError, X.meth, c)
 
+    def test_super_init_leaks(self):
+        # Issue #26718: super.__init__ leaked memory if called multiple times.
+        # This will be caught by regrtest.py -R if this leak.
+        # NOTE: Despite the use in the test a direct call of super.__init__
+        # is not endorsed.
+        sp = super(float, 1.0)
+        for i in range(1000):
+            super.__init__(sp, int, i)
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -10,6 +10,9 @@ Release date: tba
 Core and Builtins
 -----------------
 
+- Issue #26718: super.__init__ no longer leaks memory if called multiple times.
+  NOTE: A direct call of super.__init__ is not endorsed!
+
 - Issue #25339: PYTHONIOENCODING now has priority over locale in setting the
   error handler for stdin and stdout.
 
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
@@ -7336,9 +7336,9 @@ super_init(PyObject *self, PyObject *args, PyObject *kwds)
         Py_INCREF(obj);
     }
     Py_INCREF(type);
-    su->type = type;
-    su->obj = obj;
-    su->obj_type = obj_type;
+    Py_XSETREF(su->type, type);
+    Py_XSETREF(su->obj, obj);
+    Py_XSETREF(su->obj_type, obj_type);
     return 0;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -7336,9 +7336,9 @@ super_init(PyObject self, PyObject args, PyObject *kwds)`
`7336`	`7336`	`Py_INCREF(obj);`
`7337`	`7337`	`}`
`7338`	`7338`	`Py_INCREF(type);`
`7339`		`- su->type = type;`
`7340`		`- su->obj = obj;`
`7341`		`- su->obj_type = obj_type;`
	`7339`	`+ Py_XSETREF(su->type, type);`
	`7340`	`+ Py_XSETREF(su->obj, obj);`
	`7341`	`+ Py_XSETREF(su->obj_type, obj_type);`
`7342`	`7342`	`return 0;`
`7343`	`7343`	`}`
`7344`	`7344`