ISN patch that applies cleanly with git apply

I am reviewing Jan Otto's ISN patch, as part of the ongoing
commit-fest. I've attached a revised patch, which was produced with
git diff. The original was produced against CVS head.

The patch produces this warning when applied to master:

peter(at)linux-peter-home:~/postgresql> git apply isbn_git_patch.patch
isbn_git_patch.patch:13: trailing whitespace.

isbn_git_patch.patch:554: new blank line at EOF.
+
warning: 2 lines add whitespace errors.

Peter Eisentraut asked Jan to produce a regression test for the ISN
contrib module, which he is apparently working on. I would like to see
him more clearly explaining how that will work though - so far, it's
really just been described in very broad strokes.

If a regression test cannot be produced in time, is that likely to be
a deal-breaker for getting this committed?

--
Regards,
Peter Geoghegan