Subject: Re: bug#78719: 30.1; [PATCH] Add functions `string-common-prefix' and `string-try-completion'

From: Stefan Monnier <[email-masked]>
Date: Sat, 05 Jul 2025 11:26:15 -0400

>>    (let* ((completion-ignore-case nil)
>>           (completion-regexp-list regexp-list)
>>           (prefix (try-completion "" collection)))
>>      (if (stringp prefix)
>>          prefix
>>        (if (eq t prefix)
>>            
>>          ""))))

Side note.  I recently pushed yet another bug fix where we called
`(all/try)-completion` without binding `completion-regexp-list` and thus
ended up inheriting that regexp constraint from the context.

It's great that we can pass additional arguments via dynamic-binding,
but in the same sense as "it's great that we can patch things with
`advice-add`": it's better when we don't have to.

        Stefan