changeset viewer fails for changes with deletions (no node at revision)

Using trac version 0.12.2-1build1 with subversion version 1.7.5-1ubuntu1~precise+svn1 (from ppa:svn/ppa)

Steps:
1) add and modify several text files over 2 or 3 revisions in a trac-viewed svn repository.
2) view each of those changesets in trac
3) delete one of the files in subversion (creating a new revision)
4) view that changeset in trac

Expected results:
the changeset in 4 can be viewed

Actual results:
trac shows an error page instead; more details can be seen on the console

Extra information:
The bug is http://trac.edgewall.org/ticket/10414 and is reportedly fixed in 0.12.3 (I did not verify this).
After I applied the changeset linked in that ticket (http://trac.edgewall.org/changeset/10833) and completely resync'ed the repository, step 4 works. Note that it is not sufficient to resync the affected revision.

This also affects people who started with an older version of trac and/or svn and then upgrade--in that case, only newly-created revisions with deletions are affected.

Since 12.04 is an LTS, would it be possible to backport that one fix?
I've noticed no adverse effects since recently installing that patch (by directly patching /usr/share/pyshared/trac.