Fix infinite recursion in cythonize().

--HG--
extra : transplant_source : %CCQr%12%0AY%10%1F%DA%5D%CD%7C4%C8%CA%B4%90%81%3Er

Cython/Build/Dependencies.py

@@ -282,8 +282,8 @@ class DependencyTree(object):
 
     #@cached_method
     def package(self, filename):
-        dir = os.path.dirname(filename)
-        if os.path.exists(os.path.join(dir, '__init__.py')):
+        dir = os.path.dirname(os.path.abspath(filename))
+        if dir != filename and os.path.exists(os.path.join(dir, '__init__.py')):
             return self.package(dir) + (os.path.basename(dir),)
         else:
             return ()