can't delete attachment if no HTML preview is available

[jhmark@…]

Be a user with WIKI_DELETE privilege. Attach an MS Word document to a Trac page (e.g. foo.doc). Click on the link to the attachment. This goes to a page saying "HTML preview not available". Notice there is no "Delete Attachment" button, and no way to delete the attachment (as far as I can tell).

If a text file is attached, the user can delete it, as expected.

[sid]

Potentially a duplicate of #3271. What browser (and version) are you using?

[jhmark@…]

I think you are right. The problem goes away if I close all browser sessions and then reopen. (Firefox 2.0.0.8 on Winxp.)

I have confirmed that after the Trac permissions are changed, Firefox still caches an old version of the page, even after pushing Refresh.

[sid]

Strangely, #3271 says that it only happens with text files, not binary ones such as the problem you reported. This does appear to be a caching problem though.

[osimons]

Is it a problem or not? Close?

[anonymous]

OK by me to close.

If the permissions are changed using trac-admin (so the user gains WIKI_DELETE privilege), a Firefox user may see out of date pages (without the Delete Attachment button) until the Firefox cache is cleared. This seems not ideal, but acceptable.

[Christian Boos]

Simple fix:

trac/attachment.py

@@ -617 +617 @@
 
     def _render_view(self, req, attachment):
         req.perm(attachment.resource).require('ATTACHMENT_VIEW')
-        req.check_modified(attachment.date)
+        can_delete = 'ATTACHMENT_DELETE' in req.perm(attachment.resource)
+        req.check_modified(attachment.date, str(can_delete))
 
         data = {'mode': 'view',
                 'title': get_resource_name(self.env, attachment.resource),

[Christian Boos]

Patch committed as r6656.