Presently, the Subversion post-commit hook only accepts numbers (and GNATS categories) in the PR field of commit logs. Since practically everything is a URL these days, and therefore everything else knows how to _handle_ a URL, the hook should accept URLs in the PR field.
Modify hook scripts:
Update Subversion's commit log template in src and ports:
Created attachment 202564 [details]
URL redirect CGI script
Here is a working CGI script that could someday be used in place of Bugzilla to keep commit log URLs alive long after we migrate away from Bugzilla.