Right now, post-review's svn-diff functionality will produce patches with paths like '--- dir1/file%20with%20spaces'. This form is rejected both by the RB server (when trying to view diffs) and by standard patch tools.

This occurs because post-review uses the 'URL' line of 'svn info' output with the repository removed.
With my client ('Subversion command-line client, version 1.5.1.'), this output is URL-escaped (as one would expect, since it's a URL).

This patch url-unescapes that output.

post-review r1477 on Ubuntu 8.04 32-bit with 'Subversion command-line client, version 1.5.1.' (compiled from Ubuntu Intrepid source package 1.5.1dfsg1-1ubuntu2) - with this fix, posted diffs against filenames with spaces are viewable, whereas they were not before.