OS X: Launcher Crashes When Offline

Launcher 1.2.8 crashes when offline.

I expected the launcher to open without internet so I can save some battery.

I opened the launcher, and there was nothing except for a blank window called 'Minecraft Launcher 1.2.8', and I need to force quit it to close.

Steps to Reproduce:
1. Turn off any internet connection.
2. Open Minecraft Launcher.
3. You now see that blank window staring at you.