This works fine for me in EGit 2.0.0.201204130249 and has worked fine for quite a long time, even before 1.0 as I recall. You're sure you have Quick Diff configured to use "A Git Revision" as the point of reference? The behavior you describe sounds like the "Version on Disk" option.
Speaking of these reference options, is there some reason why the Git option isn't called "Git HEAD revision"? "A Git Revision" seems pointlessly vague. Or is there some way I don't know about to make Git quick-diff be relative to a Git reference other than HEAD?
looks like EGit does not work in editor at all. I can clone projects from EGit perspective. But in Editor window add, stage, commit are not possible. Context menu of a file doesn't offer those commands. Any thoughts?
Usually it means you imported the projects without going through git.
The easiest fix is to remove the projects from the workspace and re-import them, either with "File -> Import -> Git - > Projects from Git", or by adding your local clone to the Git Repositories view and then running "Import Projects..." from the right-click menu of the newly added repository entry.
is there some way I don't know about to make Git quick-diff be relative to a Git reference other than HEAD?
No one responded to this but I just stumbled over the answer: the right-click menu of commits in a History list includes "Quick Diff -> Set as Baseline". So that's apparently how the Quick Diff can be relative to something other than HEAD.
Yet another useful but somewhat hidden egit feature to add my egit notes.