[Trac] update on another overwhelmingly popular patch

[Tristan Seligmann]

Justus Pendleton wrote:
> I've finished up making trac version control agnostic and adding a darcs
> backend.  No doubt there are still errors since I haven't done comprehensive
> testing but all of the functionality is there and seems to mostly work.  I've
> also changed trac-admin to allow creation of non-svn repositories.

This is great! I've recently been moving to darcs from subversion for a
lot of my projects; now I don't have to lose half of my Trac functionality.

> The only real "big" change is that revision identifiers can no longer be assumed
> to be integers.  This meant the db schema for the revision table changed.  Right
> now this takes advantage of the fact that SQLite is typeless.  If trac actually
> starts supporting other databases that enforce type checking then it would be
> necessary to provide different schemas for different version control backends. 

Digits can be stored as a character type too; I can't think of any
*numeric* operations that need to be performed on a revision identifier;
such operations wouldn't work with other SCM backends like darcs, anyway.

--
Tristan