Looks like a possible RFC 2616 MUST violation. HTTP specifically does not allow intermediaries to add Max-Forwards header (see bug report URL or links from the test case trace for RFC quotes). A different way to detect loops should be used (Via: or an extension header). See attached trace(s) for details and ways to reproduce the violation mentioned above. Test case IDs in the trace link to human-oriented test case description and RFC quotes, if available.
Created attachment 4447 [details] test case trace
Created attachment 5843 [details] Patch to fix this
Please test the attached patch to see if it fixes this problem.
FYI: I tried to test the patch, but I am getting apparently unrelated coredumps when using fresh code from CVS (Apache/2.1.0-dev). I will try again later in hope that CVS HEAD code becomes more stable. If there is a particular snaphot I should try instead of HEAD, please provide instructions.
Mr. Co-Advisor, Regarding your comment that something in 2.1-dev is causing segfaults... Some code known to lead to segfaults in 2.1-dev was backed out last night, so you may wish to cvs update and then again try the recommended patch for this problem.
CVS HEAD updated around 'Mon Apr 28 15:00:00 UTC 2003', with the attached patch applied, does not exhibit the problem. Looks like we can consider the bug fixed. I will attach the successful test case log.
Created attachment 6049 [details] successful test case
Reopening the bug because httpd-2.0.54 is still adding Max-Forwards. The patch that fixed the problem does not seem to be commited. If the patch was backed out, I apologize (but let's mark this bug report as WONT FIX then).
Fixed in trunk in r581117: * Will default to strict protocol-compliant * Old behaviour is available, controlled (as before) by ProxyMaxForwards directive.
Fixed in r582635.