Bug#601033: apache2.2-common: AddOutputFilterByType is deprecated but used in deflate.conf

[Andrew Pimlott <andrew@pimlott.net>]

Excerpts from Stefan Fritsch's message of Tue Nov 16 15:03:05 -0800 2010:
> On Friday 22 October 2010, Andrew Pimlott wrote:
> > It gets weirder: if I change text/plain to text/html, the encoding
> > is not added.  It seems that AddOutputFilterByType catches proxied
> > requests if text/plain appears in its list of mime types, as if
> > all proxied requests were considered text/plain.
> 
> Do you have DefaultType text/plain set somewhere? If yes, try to not 
> set that for the reverse proxied requests.
> 
> I could imaging (but have not checked) that the processing order is 
> like this:
> - DefaultType sets the content type
> - AddOutputFilterByType looks at the content type
> - mod_proxy sets the content type to what was received from the 
> backend server

I thought surely this was right, but I tried it, and no.  The only
DefaultType setting is in /etc/apache2/apache2.conf, and when I change
it from text/plain to foo/bar (or comment it out), it still gzip-encodes
when text/plain is in the AddOutputFilterByType, and doesn't otherwise.

Even if it were the case, it wouldn't matter, because I still couldn't
control gzip-encoding by mime type using AddOutputFilterByType.  It
looks like AddOutputFilterByType just doesn't work right (by design?) in
the proxy case.  So I still think it should not be enabled by default.

Andrew