When pulling from a non hg repository URL (e.g. http://www.kernel.org/hg) you geta pretty obscure error (zlib: uknown compression type). The attached patch modifies hgweb.py and hg.py to supply and check a 'Content-type: application/hg-0.1' HTTP header for the branches, between and changegroup commands, so that we know it's a proper hg repo before snarfing the input. Comments appreciated!

Metadata-Version: 1.0
Name: mercurial
Version: 0.6
Summary: scalable distributed SCM
Home-page: http://selenic.com/mercurial
Author: Matt Mackall
Author-email: mpm@selenic.com
License: GNU GPL
Description: UNKNOWN
Platform: UNKNOWN