On Tue, 31 May 2011, Graham Leggett wrote:
On 31 May 2011, at 2:19 PM, Stefan Fritsch wrote:
if I use mod_filter to configure mod_deflate like this:
BrowserMatch ^Mozilla/4 no-gzip
BrowserMatch "\bMSIE [7-9]" !no-gzip
Header append Vary User-Agent env=!dont-vary
FilterDeclare compress-response
FilterProvider compress-response DEFLATE Content-Type $text/
FilterProvider compress-response DEFLATE Content-Type
$application/x-javascript
FilterProtocol compress-response change=yes;byteranges=no
How can I make sure in 2.2.x that the vary header is only added if the
DEFLATE filter is actually inserted into the filter chain?
Surely the DEFLATE filter should be responsible for creating a Vary header,
and adding itself to a Vary header if one already exists?
Or am I misunderstanding you?
The DEFLATE filter can't know which headers contributed to the decision if
it is activated or not. The necessary Vary header depends on the
configuration that inserts the filter and/or sets "no-gzip". Therefore,
mod_filter would be a logical place to add the Vary header. Especially
because it can also depend directly on request headers:
FilterProvider compress-response DEFLATE req=User-Agent !/MSIE/
But there isn't any code in mod_filter to add Vary headers.
