[Zope] Apache 1.3.26 cache problem with ImageFile (misc_ and p_ images) ZOPE 2.7

[Steven Hayles]

I think I'm seeing a bug in the 304 handling of Apache or ImageFile (as 
used by misc_ and p_ images such as /p_/pl the plus in a box). I have 
Apache working as a proxy/cache in front on ZOPE. Everything is fine 
until I perform a forced refresh on one of these images. ZOPE replies to 
Apache with a 304 status but with a Content-length header of 0. From 
then on, Apache serves a zero length image.

The code for FSImage and Image sets the Content-length header to the 
length of the data that would have been sent. Image has the comment:

   # Set header values since apache caching will return Content-Length
   # of 0 in response if size is not set here

Does the code for ImageFile need to do similarly, or do I just need a 
later version of Apache?

Thanks

Steven