Hi all Bug 38895 (Http headers with an underscore "_" change into hypen "-") points out that the IIS Tomcat Connector uses (by default) the CGI style headers from IIS, and thus mangles underscores in header names.
There's a USE_RAW_HEADERS define that will force the use of the raw HTTP headers and avoid this problem, so I'd propose that we make that behaviour the default. I can't see a good reason to retain the option to use the CGI style headers when we've got the code to parse the raw headers - can anyone with a longer memory think of a good reason to retain it? https://issues.apache.org/bugzilla/show_bug.cgi?id=38895 cheers tim