Commit 58ccae27 added a new argument to _do_diff() but didn't account for it
with this caller...

https://github.com/reviewboard/rbtools/commit/58ccae27

As a result posting a code review using a path results in a stacktrace...

http://code.google.com/p/reviewboard/issues/detail?id=%202881

% post-review //path/to/my/file
Traceback (most recent call last):
  File "/share/rbtools/postreview.py", line 1469, in <module>
    main()
  File "/share/rbtools/postreview.py", line 1407, in main
    diff, parent_diff = tool.diff(args)
  File "/share/rbtools/clients/perforce.py", line 290, in diff
    return self._path_diff(args)
  File "/share/rbtools/clients/perforce.py", line 414, in _path_diff
    ignore_unmodified=True)
TypeError: _do_diff() takes at least 7 non-keyword arguments (6 given)


The fix is trivial. Patch is available in the 'p4_fix_with_path' branch of my repository:

https://github.com/atagar/rbtools/tree/p4_fix_with_path
https://github.com/atagar/rbtools/commit/81e5f3d130cb907262d2560472a264e88e5d17f3

Tested by simply posting a code review for a specific file.