bug#51620: add-hook repeatedly adds same function into hook--depth-alist

[Filipp Gunbin]

On 06/11/2021 01:13 +0100, Michael Heerdegen wrote:

> Filipp Gunbin <fgunbin@fastmail.fm> writes:
>
>> diff --git a/lisp/subr.el b/lisp/subr.el
>> index 8ff403e113..2b8b6deeb0 100644
>> --- a/lisp/subr.el
>> +++ b/lisp/subr.el
>> @@ -1868,7 +1868,7 @@ add-hook
>>        (when (or (get hook 'hook--depth-alist) (not (zerop depth)))
>>          ;; Note: The main purpose of the above `when' test is to avoid 
>> running
>>          ;; this `setf' before `gv' is loaded during bootstrap.
>> -        (push (cons function depth) (get hook 'hook--depth-alist)))
>> +        (setf (alist-get function (get hook 'hook--depth-alist) 0) depth))
>>        (setq hook-value
>>          (if (< 0 depth)
>>              (append hook-value (list function))
>
> So the function would still be compared using `eq' but we would avoid to
> add dups of equal conses?  Looks reasonable to me -- Stefan?

Yep, that was the intent.