I've just resolved
an issue I had with images loaded by a _javascript_ preloader not being cached by
Internet Explorer, the images
are produced in a
Cocoon pipeline that uses the ImageReader.
The problem is with
the 'Vary' response header that is set by the reader if the 'expires' parameter
is not provided. IE will not cache
responses containing
this header unless its field value is the 'User-Agent' field, for more detail
see:
Looking at the
ResourceReader source and the associated bug report, setting the 'Vary' header
was intended to prevent IE from
caching the resource
when the 'expires' parameter was provided with a value of 0. The way the
code is implemented the header
will also be set
when the expires parameter is not provided.
Should the default
behaviour of the ResourceReader be to provide non-cachable
content?
Cheers
Adam
