Issue1217

The standard CPython zlib module throws a zlib.error:

>>> import zlib
>>> zlib.decompress('foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
zlib.error: Error -3 while decompressing data: incorrect header check

Thanks for reporting the bug and taking a crack at a patch!

If you where to add a test (probably in Lib/test/test_zlib.py) it would
make it much easier for me to accept and apply a patch.

Also, wouldn't it be better to put the try block in _get_inflate_data
since that method gets called in a few places?  And while you are
looking at it _get_deflate_data probably has a similar issue.

I have amended the patch to raise the exception in _get_inflate_data instead of 
decompress. I have also added a test to check for the desired behaviour.

I haven't attempted to look at _get_deflate_data because I am not sure that it throws an 
equivalent exception?

Fixed in r5938 with the supplied patch by njoyce (2009-01-06). Thanks!

This patch seems of reasonable scope since we should only be seeing this
error on _get_inflate, although we may have other issues in
_get_deflate, likely around resource exhaustion. But that's for another
patch to manage.