The compiler package in the python library is missing a LOAD/DELETE just before the WITH_CLEANUP instruction.

Also transformer isn't creating the with_var as an assignment.

So the following little code snippet will crash if you compile and run it with compiler.compile()

class TrivialContext:
    def __enter__(self): return self
    def __exit__(self,*exc_info): pass

def f():
    with TrivialContext() as tc:
        return 1
f()

The fix is just a few lines. I'm enclosing a patch against the python 2.5 source.

I've also added the above as a test case to the test_compiler.py file.

regards,
-Kirat

Thanks for the patch, this is fixed now in rev. 53575, 53576 (2.5).