This fixes the problem that patching would stop at the first file that has a
conflict. We always want to patch all files.
Also, it's faster for large patches, and the code is a little bit simpler too.
The patch contains changes to two files; the first one conflicts, the second
doesn't. Note how it only applies changes to the first file at this point in the
branch; we'll fix this in the next commit.
This test would fail on master for multiple reasons.
