bug#54653: 28.0.92; incorrect modification of completion-at-point-functions

[Michael Heerdegen]

Holger Schurig <holgerschurig@gmail.com> writes:

>   (message "NOW %s %s" completion-at-point-functions (local-variable-p
> 'completion-at-point-functions))
>
> emits
>
>   NOW (elisp-completion-at-point t) t
>
> I think it is a bug that there is a "t" at the end of the list.

That `t` stands for "also run the global value of the hook" - see
(info "(elisp) Running Hooks"):

     If the hook variable is buffer-local, the buffer-local variable
     will be used instead of the global variable.  However, if the
     buffer-local variable contains the element ‘t’, the global hook
     variable will be run as well.

Michael.