authz gives "Permission Denied" when viewing empty changeset

[jander@…]

If authz is enabled, trying to view an empty changeset will result in a "Permission Denied" error. Discovered in 0.10.3; inspection suggests the same bug currently exists in the trunk.

Suggested fix, in versioncontrol/svn_authz.py (there's probably a prettier way to do this):

     def has_permission_for_changeset(self, rev):
+        seen_change = 0
         changeset = self.repos.get_changeset(rev)
         for path,_,_,_,_ in changeset.get_changes():
+            seen_change = 1
             if self.has_permission(path):
                 return 1
+        if seen_change == 0:
+            return 1
         return 0

[sid]

In the path you have, 1 will always be the returned value. That doesn't seem quite right...

[anonymous]

Replying to sid:

In the path you have, 1 will always be the returned value. That doesn't seem quite right...

Hm, so it will. I wasn't expecting get_changes() to weed out unauthorized paths. In that case, I retract my quick fix.

[hyuga <hyugaricdeau@…>]

I'm pretty sure there's already a ticket for this, but I can't find it. Also, I'm pretty sure this has been fixed, but I'm not positive.

[osimons]

I see this one too - I've got a repos with an empty changeset, and permissions stop me from viewing it (not much to see, but still...). Repos is not scoped, it has authz but I of course have permissions. Disable the authz file setting and it displays. I've tried to rewind my 0.11 stable some 1000 revisions back, and nothing changes - I suspect this problem is not new.

My changeset is many years old, and I have problems recreating an 'empty' changeset now. How do they arise? I have a feeling it was old Subversion (like 1.2.3 at the time) and perhaps just a property change on root or something (like an svn:ignore perhaps), or something similar that at the time left no permanent mark in the revision log. Anyone know?

The empty changeset caused another problem following [8184], so more added to #5640.

[jander@…]

In my case, large numbers of empty revisions were created when I split a repository in two with an 'svnadmin dump | filter | svnadmin load' pipeline. I think the tool did it automatically (or maybe I asked with a flag), but I also wanted the revision numbers to line up to avoid having to play stupid games with revision references in externals.

Also, according to ​http://subversion.tigris.org/svn_1.6_releasenotes.html ("Detection of tree conflicts" section), svn versions before 1.6 will commit an empty revision if asked to commit delete a file that has already been deleted. So you don't need crazy admin tricks, just bad luck.

[rblank]

I'll try to solve this together with #5640.

[rblank]

Moved alongside #5640.

[rblank]

This should be fixed with [9082], where the AuthzSourcePolicy grants permission to empty changesets as well as non-empty changesets where access is granted to at least one modified file.