RE: I can't yank regexp for/into isearch-forward-regexp's pmpt

[Drew Adams]

    > (defun isearch-yank-kill-as-regexp ()
    >   "Like `isearch-yank-kill', except during regular expression search:
    > Search for the text that matches the string (as a regexp) instead of
    > searching for the literal string itself."
    >   (let ((isearch-regexp nil))
    >     (isearch-yank-kill)))
    > 
    > (define-key isearch-mode-map "\M-z" 'isearch-yank-kill-as-regexp)
    
    | For some reason, when using `C-M-s' followed by `M-z', the 
    | search seems to always start at the end of the buffer. So, it
    | first fails, and then it can succeed on overwrap search
    | (repeating `C-s'). This problem doesn't occur
    | for simple `C-s' search. I'm not sure why this happens.
    
    I suspect it has something to do with the global binding of M-z to
    zap-to-char and/or the squirrely business with isearch-other-meta-char,
    which I don't understand.  Does the problem go away if you bind a
    different meta-character or a control-character to
    isearch-yank-kill-as-regexp?
    
No, I get the same result with just `C-o', instead of `M-z':

(define-key isearch-mode-map "\C-o" 'isearch-yank-kill-as-regexp)