Get delattr() working

src/capi/object.cpp

@@ -493,14 +493,16 @@ extern "C" int PyObject_GenericSetAttr(PyObject* obj, PyObject* name, PyObject*
     }
 
     BoxedString* str = static_cast<BoxedString*>(name);
+    incref(str);
     internStringMortalInplace(str);
+    AUTO_DECREF(str);
 
     assert(PyString_Check(name));
     try {
         if (value == NULL)
             delattrGeneric(obj, str, NULL);
         else
-            setattrGeneric<NOT_REWRITABLE>(obj, str, value, NULL);
+            setattrGeneric<NOT_REWRITABLE>(obj, str, incref(value), NULL);
     } catch (ExcInfo e) {
         setCAPIException(e);
         return -1;
@@ -1139,8 +1141,8 @@ extern "C" void _Py_NegativeRefcount(const char* fname, int lineno, PyObject* op
     char buf[300];
 
     PyOS_snprintf(buf, sizeof(buf), "%s:%i object at %p has negative ref count "
-                                    "%" PY_FORMAT_SIZE_T "d",
-                  fname, lineno, op, op->ob_refcnt);
+                                    "%" PY_FORMAT_SIZE_T "d.  \033[40mwatch -l *(long*)%p\033[0m",
+                  fname, lineno, op, op->ob_refcnt, &op->ob_refcnt);
     Py_FatalError(buf);
 }
 

src/runtime/builtin_modules/builtins.cpp

@@ -511,13 +511,15 @@ Box* bltinImport(Box* name, Box* globals, Box* locals, Box** args) {
 }
 
 Box* delattrFunc(Box* obj, Box* _str) {
-    assert(0 && "check refcounting");
     _str = coerceUnicodeToStr<CXX>(_str);
 
-    if (_str->cls != str_cls)
+    if (_str->cls != str_cls) {
+        Py_DECREF(_str);
         raiseExcHelper(TypeError, "attribute name must be string, not '%s'", getTypeName(_str));
+    }
     BoxedString* str = static_cast<BoxedString*>(_str);
     internStringMortalInplace(str);
+    AUTO_DECREF(str);
 
     delattr(obj, str);
     return incref(None);

test/tests/change_delattr.py

-# expected: reffail
 class C(object):
     pass
 

test/tests/delattr.py

-# expected: reffail
 #delete attribute of built-in types 
 def del_builtin_attr(o):
     try:

test/tests/object_default_behavior.py

-# expected: reffail
 class C(object):
     def __delattr__(self, attr):
         print "delattr", attr