Grab the war (just verified again with 1.460) and run with 'java -jar jenkins.war'. Then send a HEAD request and observe that the server returns a body (this is best done by using 'telnet localhost 8080' and sending 'HEAD / HTTP/1.0' - tools like curl and lwp-request will suppress any received body).

This specifically causes issues with the Eclipse Mylyn plugin as that sends a HEAD request followed by a GET - because the connection is kept alive between the two requests, the parsing of the second response fails since it tries to parse the body from the HEAD as the http response headers of the GET.

Note that running Jenkins in Tomcat does not have this issue.