The following headers in a PUT request should either be evaluated, or lead to a 501 status (see RFC2616, Section 9.6, Paragraph 1, last sentence): Content-Range, Content-MD5 In addition, all request headers starting with "Content-" not understood by the server should cause a 501 status, such as: Content-Foobar This is currently not the case.
fixed in trunk in r1026746
Backported to 2.2.x as r1068310.
The fixes have been reverted both in trunk and 2.2.x. See http://mail-archives.apache.org/mod_mbox/httpd-dev/201102.mbox/%3C9A5A8B62-ED16-4BD3-97DA-8475026BB81D@gbiv.com%3E