Re: diff-mode-hook (was Re: minor bug in next-error-follow-minor-mode?)

[Richard M. Stallman]

    But that failed, and then I tried a function that did (setq foo 42),
    and that didn't seem to set foo.  

    I suspect diff-mode doesn't call diff-mode-hook.

The disassembled code says that it does.  It uses run-mode-hooks.
Under some circumstances the running of those hooks can be delayed
till when a calling function exits, but that is supposed to occur
only if it is called from anothetr major mode.