protocol/5175: Forcing Content-Type to be set

[Christian Gilmore <cg...@research.att.com>]

>Number:         5175
>Category:       protocol
>Synopsis:       Forcing Content-Type to be set
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Wed Oct 20 15:30:01 PDT 1999
>Last-Modified:
>Originator:     cgilmore@research.att.com
>Organization:
apache
>Release:        1.3.9
>Environment:
n/a
>Description:
Apache forces a content-type string to be set in its http response even though
RFC 2068 7.2.1 states:

   Any HTTP/1.1 message containing an entity-body SHOULD include a
   Content-Type header field defining the media type of that body.

I believe there should be an option to not set a content-type in a response.
The specific case where this is true is of a proxy. The proxy module that ships
with apache does not add a content-type header when none is found in the
response from the remote server. I've written a specialized proxy handler with
mod_perl. The proxy does the right thing by not modifying (or inserting) the
content-type header, but during http_protocol.c's ap_send_http_header function,
a content-type header is forced onto the response:

    if (r->byterange > 1)
        ap_table_setn(r->headers_out, "Content-Type",
                  ap_pstrcat(r->pool, "multipart", use_range_x(r) ? "/x-" : "/",                          "byteranges; boundary=", r->boundary, NULL));
    else if (r->content_type)
        ap_table_setn(r->headers_out, "Content-Type", r->content_type);
    else
        ap_table_setn(r->headers_out, "Content-Type", ap_default_type(r));
>How-To-Repeat:

>Fix:
I would suggest adding a "None" option to the DefaultType directive to
accomodate situations such as the above, which abide by the flexibility
provided by the HTTP specification.
>Audit-Trail:
>Unformatted:
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