Commit 0a66c001 authored by Luca Toscano's avatar Luca Toscano
Browse files

Merge r1769899 from trunk: 

Added a note in the mod_headers docs about Content-Type and setifempty

This note has been added as a follow up of a stack overflow post
(thanks to Michael Allan for the research):

http://stackoverflow.com/questions/29398123/apache-2-4-set-mime-type-of-file-without-extension

After a chat in #httpd-dev it seems that the issue boils down to how %{CONTENT_TYPE}
is evaluated in util_expr_eval.c (r->content_type) vs how setifempty is (only a check
of the response headers). This particular behavior might be a bug or feature,
but it is worth to alert our users.

Submitted by: elukey


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1770153 13f79535-47bb-0310-9956-ffa450edef68
parent dc2ea326

docs/manual/mod/mod_headers.xml

+11 −2
Original line number Diff line number Diff line
@@ -410,8 +410,17 @@ available in 2.4.10 and later</compatibility> 


    <dt><code>setifempty</code></dt>

    <dd>The request header is set, but only if there is no previous header

    with this name.<br />

    Available in 2.4.7 and later.</dd>

    with this name.

    <note>

    The Content-Type header is a special use case since there might be

    the chance that its value have been determined but the header is not part

    of the response when <code>setifempty</code> is evaluated.

    It is safer to use <code>set</code> for this use case like in the

    following example:

    <highlight language="config">

    Header set Content-Type "text/plain" "expr=-z %{CONTENT_TYPE}"

    </highlight>

    </note></dd>



    <dt><code>unset</code></dt>

    <dd>The response header of this name is removed, if it exists.