bug#61535: 29.0.60; choose-completion erases in-region buffer

[Juri Linkov]

>> M-RET is bound to minibuffer-choose-completion in 
>> completion-in-region-mode-map.
>> minibuffer-choose-completion let-binds completion-use-base-affixes to t
>> before calling choose-completion.  Therefore completion-use-base-affixes
>> should be ignored in choose-completion for completion-in-region-mode.
>
> OK, thanks for the explanations.  I wonder if some of the above should
> be in comments to the code, though.

Added to comments.

> Please install the patch on emacs-29.

Done.