bug#81411: 31.0.90; Selecting completion for completing-read-multiple does not respect completion boundaries

> Cc: [email protected]
> Date: Mon, 03 Aug 2026 17:35:53 -0400
> From: Aaron Zeng via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <[email protected]>
> 
> I spent some time staring at this and ended up coming up with a patch.
> I noticed a separate issue where the existing code was not finding the
> boundaries of the element correctly (if crm-separator matches more
> than one character), so the first patch changes it to use the
> crm--completion-command helper to come up with the boundaries.
> 
> The second patch fixes the initial reported bug.  Within the
> boundaries of the element, it now calls completion-boundaries to get
> the new boundaries of the part of that element to be completed.
> 
> On my machine, I tested that it fixes my initial reproduction example
> as well as the downstream issue I noticed in my site's extensions, but
> would appreciate any additional feedback and testing.

Thanks.  Spencer and Stefan, any comments to the patch?