Whenever I perform an action in SourceTree which alters a file in my git repo (e.g. "Discard hunk"), the edited file's permissions change from 664 to 644. This is breaking my system, because other users in the files' group need write permission.
Why is this happening, and how do I stop it? Changing my umask value did not help. I'm using OSX Mountain Lion.
EDIT after a week with no answer:
After further research and system tweaks, I'm still seeing SourceTree treating my files' permissions incorrectly. Every single file it touches gets set to 644, regardless of my umask value. I even followed the official instructions from Apple on how to set your umask for applications, and that didn't work.
Using git from the command-line does respect my umask value, so this is very frustrating.