Fix SF item #876278: Unbounded recursion in modulefinder.

Already backported to release23-maint.

Lib/modulefinder.py

@@ -245,6 +245,9 @@ def import_module(self, partname, fqname, parent):
         if self.badmodules.has_key(fqname):
             self.msgout(3, "import_module -> None")
             return None
+        if parent and parent.__path__ is None:
+            self.msgout(3, "import_module -> None")
+            return None
         try:
             fp, pathname, stuff = self.find_module(partname,
                                                    parent and parent.__path__, parent)
@@ -392,6 +395,7 @@ def add_module(self, fqname):
 
     def find_module(self, name, path, parent=None):
         if parent is not None:
+            # assert path is not None
             fullname = parent.__name__+'.'+name
         else:
             fullname = name

Misc/NEWS

@@ -306,6 +306,8 @@ Extension modules
 Library
 -------
 
+- Bug #876278: Unbounded recursion in modulefinder
+
 - Bug #780300: Swap public and system ID in LexicalHandler.startDTD.
   Applications relying on the wrong order need to be corrected.