Amend commit message doesn't update when branch is switched

[Arcanemagus]

Prerequisites

• Have you tried to reproduce the problem in Safe Mode?
• Have you followed all applicable steps in the debugging guide?
• Have you checked the FAQs on the message board for common solutions?
• Have you checked that your issue isn't already filed?

Description

The commit message brought up by enabling "Amend" doesn't update when the branch is switched.

Steps to Reproduce

1. Open Atom in safe mode to a project that uses git
2. Enable "Amend" and note the commit message shown
3. Disable "Amend"
4. Switch the branch to a different branch, either from within Atom or any external tool.
5. Enable "Amend" and note that the commit message shown hasn't updated.

Expected behavior:

The commit message shown when "Amend" is enabled should always be the latest commit on the current branch, whatever that may be.

Actual behavior:

The commit message doesn't update when the branch is changed.

Reproduces how often:

100% of the time.

Versions

Atom    : 1.24.0-beta3
Electron: 1.6.15
Chrome  : 56.0.2924.87
Node    : 7.4.0
apm  1.18.12
npm  3.10.10
node 6.9.5 x64
atom 1.24.0-beta3
python 2.7.14
git 2.15.1.windows.2
visual studio 2015

OS: Windows 10 x64

Additional Information

This is related to #1219, if not the same root cause.

[smashwilson]

Fixed by the recent commit view 🎶