How can I get Emacs to revert all unchanged buffers when switching branches in git?

Often, when I switch branches in git, if the files are open in emacs, then emacs asks if I want to revert them (as it thinks they've changed on disk) even though the contents are identical.

Firstly I'd like to find a way for emacs to not ask me about it at all if the contents on disk are identical to those in the buffer.

Secondly I'd like a command that reverted (without query) all my open buffers that have no unsaved changes, and queried me about those that do have unsaved changes.

Alternatively开发者_JAVA技巧, I'd be open to suggestions about other solutions, ways of working, etc I could try. I'm fairly happy writing emacs-lisp if people can give me pointers on where to start.

PS I'm using Aquamacs on OSX if that matters.

Edit:

Well, I've found the revbuffs package to be pretty much what I need. Certainly enough to stop me wanting to try and write anything new myself. (I mapped revbuffs to Cmd-R which works quite nicely. Kind of similar to Cmd-R in other Mac apps).

Global-auto-revert mode would have been a perfectly fine solution, and I wish I could choose two answers. I prefer revbuffs simply because of a, possibly irrational, feeling of wanting to be in control of what happens.

I'd kind of guessed that if I accessed git from within emacs, then it could probably be handled easier, but I currently prefer accessing git through the commandline. (I haven't quite been using emacs long enough to make it my operating system). I will investigate magit a little more thoroughly though.

Edit2:

I've been using magit for a year now and can highly recommend it for dealing with git from within emacs. However I still use revbuffs whenever I do a rebase outside of emacs.

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Perhaps you'd like the global auto-revert mode. Try running global-auto-revert-mode and if you like it you can add (global-auto-revert-mode) to your ~/.emacs file.

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Try the revbufs package:

revbufs.el is a tiny Emacs package that safely reverts your buffers when you have files being edited both in Emacs and via external tools (e.g., code generators such as Jomtool)...

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Magit package do this automatically, when you activate magit-ionotify-mode (inotify need emacs 24.4 on linux). Its description you can find here.