bug#10827: 24.0.93; M-RET behaviour with M-x diff-buffer-with-file RET

[Stefan Monnier]

> 1. Make some modification to a file and don't save it.  
> 2. Do M-x diff-buffer-with-file RET.
> 3. Pick a modified line and press M-RET.
> 4. Now the user is prompted for a file.

When I try it, Emacs just jumps to the corresponding line in the
original buffer without prompting the user for a file name.
Could the problem be triggered by some particular customization
of yours?  (I.e. try to reproduce it with "emacs -Q" and if the problem
doesn't appear there, try to figure out which part of your config
triggers the problem).


        Stefan