Re: master ff3f17ca3cd: choose-completion: Retain the suffix after completion boundary

[Dmitry Gutov <dmitry@gutov.dev>]

Hi Eshel,

On 10/05/2024 19:10, Eshel Yaron wrote:

>> branch: master
>> commit ff3f17ca3cdd9e82355942f577e7807acc76ddcd
>> Author: Dmitry Gutov <dmitry@gutov.dev>
>> Commit: Dmitry Gutov <dmitry@gutov.dev>
>>
>>      choose-completion: Retain the suffix after completion boundary
>>
>>      * lisp/minibuffer.el (completion-base-suffix):
>>      Remove as not optimal after all (bug#48356).
>>      (completion--replace): Use insert-before-markers-and-inherit.
> 
> [...]
> 
>> -      (insert-and-inherit newtext)
>> +      (insert-before-markers-and-inherit newtext)
> 
> It seems that this change breaks the cycling behavior of
> minibuffer-force-complete.  You can see the problem by saying:
> 
> 1. emacs -Q
> 2. (setq completion-cycle-threshold t)
> 3. Open some buffers
> 4. C-x b TAB TAB TAB ...
> 
> The repeated TAB presses are expected to cycle through the completion
> candidates (this is the behavior in Emacs 29 for example) but now each
> TAB appends to the minibuffer input instead of replacing it.

Thanks for reporting that. Indeed cycling was a special case because it 
tracks BEG with a marker.

This should be fixed in commit f0009c2f5ae, hopefully without regressing 
on other cases.