go-lang-plugin-org/go-lang-idea-plugin — pull request #996 by dlsniper (2014-11-14 22:31:40+00:00)
Title: Fix NPE when IDEA is closing and the action is invoked for the unsaved file

I came across this by mistake.
It happens when you close IDEA on a previously backgrounded save action. It's a really hard one to replicate but at least the fix is easy :)