Comment 1 for bug 1348865

You can open file libgearman-server/plugins/protocol/http/protocol.cc , find 'bad request line:' and 'bad method:', then chang 'GEARMAND_SUCCESS' to 'GEARMAND_INVALID_PACKET' after them. This way is quick for this bug.

You can also use my patch file here, but the patch file contains other patches for bug fixes and/or better support of SSL connection, planed job and HTTP protocol. Read these links below for details:
    https://bugs.launchpad.net/gearmand/+bug/1338861
    https://bugs.launchpad.net/gearmand/+bug/1352411
    https://answers.launchpad.net/gearmand/+question/252097