#2957: marshal recursion limit exceeded when importing a large .pyc file

Lib/test/test_marshal.py

@@ -113,6 +113,12 @@ class CodeTestCase(unittest.TestCase):
         new = marshal.loads(marshal.dumps(co))
         self.assertEqual(co, new)
 
+    def test_many_codeobjects(self):
+        # Issue2957: bad recursion count on code objects
+        count = 5000    # more than MAX_MARSHAL_STACK_DEPTH
+        codes = (ExceptionTestCase.test_exceptions.__code__,) * count
+        marshal.loads(marshal.dumps(codes))
+
 class ContainerTestCase(unittest.TestCase, HelperMixin):
     d = {'astring': 'foo@bar.baz.spam',
          'afloat': 7283.43,

Misc/NEWS

@@ -12,6 +12,10 @@ What's new in Python 3.0b1?
 Core and Builtins
 -----------------
 
+- Issue #2957: Corrected a ValueError "recursion limit exceeded", when
+  unmarshalling many code objects, which happens when importing a
+  large .pyc file (~1000 functions).
+
 - Issue #2963: fix merging oversight that disabled method cache for
   all types.
 

Python/marshal.c

@@ -913,8 +913,6 @@ r_object(RFILE *p)
 			Py_XDECREF(filename);
 			Py_XDECREF(name);
 			Py_XDECREF(lnotab);
-
-			return v;
 		}
 		retval = v;
 		break;