magit/magit — pull request #921 by aspiers (2013-09-23 17:49:08+00:00)
Title: magit-run-git-gui-blame: fix when linenum is missing

We can't guarantee that we'll always know which line number we want to center
the `git gui blame' process around. This fixes an error caused by attempting
to pass nil as one of the arguments to `start-file-process'.