Work around different versions of patch in unit tests
Review Request #10208 — Created Oct. 9, 2018 and submitted
Review request https://reviews.reviewboard.org/r/10164/ landed on
release-4.0.x, but the underlying issue was introduced on release-3.0.x.
This patch is a backport of that patch. The original commit message
We had a unit test that depended on the specific version of
installed. Newer versions of patch will accept a diff that contains no
hunks, whereas older versions will fail with a message saying that the
input contained only garbage.
We now have unit tests that check the correct behaviour happens in both
cases by replacing our call to
Ran unit tests.