RE: isearch region or thing at point.

[Drew Adams]

I'm sorry to say that I'm not in favor of `M-w'
being bound in `isearch-mode-map' for this behavior.

I'm not opposed to some key being bound for it,
though I'd prefer that we just define the command
and leave it unbound (letting users bind it if they
find it handier than just using `M-w' before `C-s').

In Isearch+ I bind `M-w' to `isearchp-kill-ring-save',
which I feel is more useful than your command, which
is a short cut for the usual Emacs keys.

`isearchp-kill-ring-save' copies the current search
string to the kill ring.

I've bound it to `M-w' in the search map since 2013,
when we moved `isearch-toggle-word' from `M-w' to
`M-s w'.

How about just adding your command and not binding
it by default?