From: John Tapsell <johnflux@gmail.com>
Date: Mon, 29 Sep 2014 09:32:27 GMT
Subject: Code changes in merge commits
Message-ID: <CAHQ6N+p1GqQfTs0H-4ij_QfkWQGfTUbWBzMC4E7LCEynPT78kA@mail.gmail.com>

Hi,

  Our team just struggled with this problem, and I've created a
simple, 3 commit large, example git repository to demonstrate the
problem:

https://github.com/johnflux/ExampleEvilness2

The code:   Adds a file, adds a security fix commit, then removes the
fix during a merge.

This happened by accident in our code during a merge, but nobody
noticed, and it was not easy to track down.

In this example, you can see that the security fix was removed by doing:

$ git log -m -p

However the following do NOT show that the security fix was removed:

$ git log -m -p .
$ git log -m -p tmp.c
$ git log -c -p tmp.c

And so on. In a large code base, this a problem.

John