IDEA 12 CE EAP - Both buffers are Read-Only in git branch diff

Hello. Question about the diff tool integration with git in IDEA. I'm using Leda having previously used IDEA 11.

Comparing working copy against a branch in IDEA used to leave the working copy ("Your version") editable, which was really nice when making little corrections here and there while reviewing a pull request. Now in Leda both buffers are Read-Only in the branch diff view. Any idea how to make the working copy editable again? Or is this a regression? Performing the exact same steps on IDEA 11 leaves my version editable.

Thanks,
Erem