Allan Odgaard in the comment for the Subverion++ bundle (I can’t find a link. The comment is a commit message in the svn commit):
This command is VERY rudimentary, but it will do a svn diff on your current file, then show a UI where you can (un)check each portion of this diff, enter a commit message, and then commit only the checked parts of the diff.
If you check or uncheck all parts, or do not enter a commit message, it won’t commit your changes.
My long-term idea is that this should be part of the standard commit window, which should use an outline view (instead of just a list) for the files, and thus have the patch portions as children for each file.
The bundle is Review directory under trunk. Check out r7438 commit by Allan.