bug#39512: 28.0.50; Add command isearch-yank-region

[Juri Linkov]

> If the region is active but empty that functionality could make sense
> (extend to the next thing at point), but when it is not empty I think it
> doesn't make too much sense in general use... but let's wait for the
> rest of the opinions.

Good point.  ‘C-SPC M-s . C-s C-s ...’ means that the user wants to
extend the region to one of the next found symbols.

But still there is an unsolved problem: ‘M-s .’ activates the *symbol*
search mode, not the default non-symbol search mode.  This means that
the yanked region will match only symbols, that is useless when the
region is longer than one symbol (the symbol search is activated by
the call of ‘isearch-forward-symbol’ in ‘isearch-forward-symbol-at-point’).

This means there is still a need to add a new command that yanks the region
but doesn't activate the symbol search mode.

> Actually, probably such a function (thing-at-point-or-region) could be
> added to thing-at-pt to use it in other functionalities too. (like
> highlight thing at point, idle highlight thing at point or region, kill
> thing at point or region and so on)
>
> It is something I have seen re-implemented in many packages here and
> there again and again, so probably it is time to provide it in vanilla.

Yes, this could be added to thing-at-pt.