SF bug #1153075: "PyXxx_Check(x) trusts x->ob_type->tp_mro".

A patch by mwh to check that user-defined mro's are reasonable
enough.

1 files changed, 31 insertions, 0 deletions

diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 2ea8186..e954a0f 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -1635,6 +1635,37 @@ def altmro():
     vereq(X.__mro__, (object, A, C, B, D, X))
     vereq(X().f(), "A")
 
+    try:
+        class X(object):
+            class __metaclass__(type):
+                def mro(self):
+                    return [self, dict, object]
+    except TypeError:
+        pass
+    else:
+        raise TestFailed, "devious mro() return not caught"
+
+    try:
+        class X(object):
+            class __metaclass__(type):
+                def mro(self):
+                    return [1]
+    except TypeError:
+        pass
+    else:
+        raise TestFailed, "non-class mro() return not caught"
+
+    try:
+        class X(object):
+            class __metaclass__(type):
+                def mro(self):
+                    return 1
+    except TypeError:
+        pass
+    else:
+        raise TestFailed, "non-sequence mro() return not caught"
+        
+
 def overloading():
     if verbose: print "Testing operator overloading..."