Problem with image attachements and CGI.

[johan@…]

Found a bug when running Trac in CGI mode. When I attach an image to a Wiki page, and then for example link to this image from my document like this:

my-trac-url/NNS/attachment/wiki/ScreenShots/nagios-demo.jpg?format=raw

If you then load this page in the browser (tested in IE and Firefox), the image will show. But if you refresh the page, the images suddenly dissapear and the alt text is shown instead. Refresh again and it shows again.. Refresh and it dissapears.. And goes on like this.. Same thing can be watched by just viewing the attachment by click on the link at the bottom of the page.

For other images stored on other places this is not a problem, works fine. Also, when running mod_python it all works as expected.

Here are HTTP logs from a working refresh (2 images):

http://svn.stromnet.org:8180/projects/NNS/attachment/wiki/ScreenShots/nagios-demo2.jpg?format=raw

GET /projects/NNS/attachment/wiki/ScreenShots/nagios-demo2.jpg?format=raw HTTP/1.1
Host: svn.stromnet.org:8180
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.7) Gecko/20050414 Firefox/1.0.3
Accept: image/png,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://svn.stromnet.org:8180/projects/NNS/wiki/ScreenShots
Cache-Control: max-age=0

HTTP/1.x 200 OK
Date: Tue, 31 May 2005 13:37:09 GMT
Server: Apache/2.0.52 (Unix) mod_ssl/2.0.52 OpenSSL/0.9.7d DAV/2 PHP/5.0.3 SVN/1.1.4 mod_python/3.1.4 Python/2.4.1
Pragma: no-cache
Expires: Mon, 26 Jul 1997 05:00:00 GMT
Content-Length: 26227
Last-Modified: Tue, 31 May 2005 11:54:48 GMT
Connection: close
Content-Type: image/jpeg
----------------------------------------------------------
http://svn.stromnet.org:8180/projects/NNS/attachment/wiki/ScreenShots/nagios-demo.jpg?format=raw

GET /projects/NNS/attachment/wiki/ScreenShots/nagios-demo.jpg?format=raw HTTP/1.1
Host: svn.stromnet.org:8180
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.7) Gecko/20050414 Firefox/1.0.3
Accept: image/png,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://svn.stromnet.org:8180/projects/NNS/wiki/ScreenShots
Cache-Control: max-age=0

HTTP/1.x 200 OK
Date: Tue, 31 May 2005 13:37:09 GMT
Server: Apache/2.0.52 (Unix) mod_ssl/2.0.52 OpenSSL/0.9.7d DAV/2 PHP/5.0.3 SVN/1.1.4 mod_python/3.1.4 Python/2.4.1
Pragma: no-cache
Expires: Mon, 26 Jul 1997 05:00:00 GMT
Content-Length: 31230
Last-Modified: Tue, 31 May 2005 11:54:58 GMT
Connection: close
Content-Type: image/jpeg

Here are HTTP logs from a non-working refresh (same 2 images):

http://svn.stromnet.org:8180/projects/NNS/attachment/wiki/ScreenShots/nagios-demo2.jpg?format=raw

GET /projects/NNS/attachment/wiki/ScreenShots/nagios-demo2.jpg?format=raw HTTP/1.1
Host: svn.stromnet.org:8180
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.7) Gecko/20050414 Firefox/1.0.3
Accept: image/png,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://svn.stromnet.org:8180/projects/NNS/wiki/ScreenShots
If-Modified-Since: Tue, 31 May 2005 11:54:48 GMT
Cache-Control: max-age=0

HTTP/1.x 200 OK
Date: Tue, 31 May 2005 13:36:52 GMT
Server: Apache/2.0.52 (Unix) mod_ssl/2.0.52 OpenSSL/0.9.7d DAV/2 PHP/5.0.3 SVN/1.1.4 mod_python/3.1.4 Python/2.4.1
Connection: close
Expires: Mon, 26 Jul 1997 05:00:00 GMT
----------------------------------------------------------
http://svn.stromnet.org:8180/projects/NNS/attachment/wiki/ScreenShots/nagios-demo.jpg?format=raw

GET /projects/NNS/attachment/wiki/ScreenShots/nagios-demo.jpg?format=raw HTTP/1.1
Host: svn.stromnet.org:8180
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.7) Gecko/20050414 Firefox/1.0.3
Accept: image/png,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://svn.stromnet.org:8180/projects/NNS/wiki/ScreenShots
If-Modified-Since: Tue, 31 May 2005 11:54:58 GMT
Cache-Control: max-age=0

HTTP/1.x 200 OK
Date: Tue, 31 May 2005 13:36:52 GMT
Server: Apache/2.0.52 (Unix) mod_ssl/2.0.52 OpenSSL/0.9.7d DAV/2 PHP/5.0.3 SVN/1.1.4 mod_python/3.1.4 Python/2.4.1
Connection: close
Expires: Mon, 26 Jul 1997 05:00:00 GMT

[Emmanuel Blot]

Same issue w/ Apache 2.0.5x and mod_python (on WinXP SP1 and Linux 2.4)

[Emmanuel Blot]

Seems to be a duplicate of #1402

[Christopher Lenz]

Is this really about Trac 0.8.1? If it's about 0.9-pre (which I suspect it is), it's likely a duplicate of #1680. And if it's about 0.8.1, it's a duplicate of #1402.