What determines key bindings in the Magit commit window?

Question

I'm a happy Magit user, and at commit time, I am accustomed to editing a commit message and then finishing the edit with C-c C-c. But sometimes that key sequence winds up bound to the compile function, as indeed my emacs init file contains the line

(global-set-key "\C-c\C-c" 'compile)

My init file also sets that key locally in a number of modes including c-mode, sml-mode, lua-mode, and so on. However, none of those modes is displayed on the mode line in the commit-edit window. And when emacs is working correctly, C-c C-c finishes the edit and returns to git as expected. However, every so often it gets wacky and insists on being bound to compile.

Following a trail of emacs lisp leads a very short distance to where Magit invokes git with $EMACSCLIENT set appropriately. Beyond that point I have been unable to diagnose how that buffer is created or where its keybindings are determined.

The problem I'm trying to solve is to set the keybindings in the commit-message edit buffer so that C-c C-c terminates the edit and returns control to git. At the moment, the only way I can do this is to exit emacs and start over. That workaround doesn't last long, and it grows tiresome.

I would welcome answers to any or all of the following questions:

1. Where are the keybindings set for that window?

2. What function is C-c C-c bound to by default?

3. Is there a mode or other hook where I can just reach in with a hammer and bind C-c C-c to the right function?

---

Addendum: the buffer's major mode is text-mode. Here is the response to C-h v major-mode RET:

Its value is text-mode
Original value was fundamental-mode
Local in buffer COMMIT_EDITMSG; global value is fundamental-mode

Answer 1

Thanks to commenters, this is what I was able to learn:

1. Some keybindings were set by an overeager after-change-major-mode-hook, which doubtless was a workaround for a legacy bug somewhere. (The question of where the correct keybinding is set remains unanswered.)

2. The function bound by default is with-editor-finish, which I eventually discovered by starting with emacs -q

3. I reached in with the hammer of after-change-major-mode-hook, or rather, I made the hammer that I already found there hit with a little less force.

Of the resources named in the comments, How can I find out in which keymap a key is bound? provided no useful information—lots of things were set to nil. But looking at the major and minor modes were most excellent hints!