Re: Recentish C-s M-y change

[Gregory Heytings via "Emacs development discussions." <emacs-devel@gnu.org>]

>> You defined C-g, C-q, C-r, C-s, C-w and C-y in 1985 (or perhaps 
>> earlier).
>
> When we changed to RET to exit, did we also change C-y to M-y?
>

No, C-y remained bound to isearch-yank-line until Emacs 24, when it was 
rebound to isearch-yank-kill.  M-y was initially unbound; it was bound to 
isearch-yank-kill in Emacs 19 and was rebound to isearch-yank-pop in Emacs 
24.

>
> I do have a memory of using M-y years ago to yank the last kill into a 
> search, and choosing M-y for that precisely because using it to exit the 
> search was pointless (since it would always get an error after a 
> search).
>

Yes, your memory is correct AFAICS.

>
> But is there really nothing else now?  I have a nonspecific memory of 
> seeing discussion of various new key bindings in search.
>

The isearch-mode-map contains a number of other keybindings indeed, and 
most of them are quite old.

No other control character is defined, except (since at least Emacs 21) 
C-\ (bound to isearch-toggle-input-method; C-\ is bound to 
toggle-input-method in global-map) and C-^ (bound to 
isearch-toggle-specified-input-method; C-^ is unbound in global-map).

The other bindings have a M- or C-M- prefix.  I guess that the discussions 
you remember were about these ones.

As Drew told you, you can get the detailed list of bindings with M-x 
describe-keymap RET isearch-mode-map RET.