Patch 1459963 (applied in 50842) needlessly breaks the
old (albeit undocumented) interface of direct access to
request.headers (which existed prior to the
introduction of method.  That patch changes the case of
the keys of the request.headers dictionary.  That seems
guaranteed to break existing code.

The attached patch reverts 50842's changes to urllib2
(it does not revert the changes to urllib) and fixes
the reported issue with a one-line fix in
AbstractHTTPHandler (.title()-case the HTTP headers
before sending them to httplib).  That fix is also more
localised to HTTP -- urllib2 knows about other
protocols too.  This patch also corrects a mis-wording
in Misc/NEWS: the old case convention was not strictly
incorrect (according to RFC 2616), but just did not
follow the usual title-case convention.

If the original patch was applied to the 2.4
maintenance branch, I guess this patch should be
applied there too.

Logged In: YES 
user_id=261020

s/(which existed prior to the introduction of method/(which
existed prior to the introduction of the .get_header() &c.
methods)/

Logged In: YES 
user_id=33168

I would like to see additional tests to ensure something
like this doesn't happen again.

Logged In: YES 
user_id=261020

Quite right, here's a patch with the missing test.

Logged In: YES 
user_id=849994

Applied as rev. 51416, 51417 (2.5)