bug#19710: 24.4.51; Isearch is broken in comints which relly on regexp

[Vitalie Spinu <spinuvit@gmail.com>]

Works. Thanks!

 >>> Juri Linkov on Wed, 18 Feb 2015 19:01:52 +0200 wrote:

 >> Relatedly, comint-bol inside multiline output regions is broken.
 >> 
 >> In shell buffer:
 >> 
 >> $ locate pwd
 >> 
 >> then go to a previous line and M-x comint-bol. It will jump all the way
 >> back to comint-prompt-regexp.

 > The following patch for the emacs-24 branch should fix this regression.

 > It distinguishes two cases: when point is on the output or input
 > depending on the field property, for the case of comint-use-prompt-regexp=nil.

 > This means that we can't support multi-line commands for the case
 > when comint-use-prompt-regexp=t because it doesn't use fields, thus
 > there is no way to distinguish input from output.

 > So for comint-use-prompt-regexp=t `M-x comint-bol' will work
 > as in the previous release, but `M-x comint-bol' will be
 > fixed for comint-use-prompt-regexp=nil:

 > diff --git a/lisp/comint.el b/lisp/comint.el
 > index c81551a..2532dd7 100644
 > --- a/lisp/comint.el
 > +++ b/lisp/comint.el
 > @@ -2267,8 +2267,6 @@ (defun comint-line-beginning-position ()
 >        ;; Use comint-prompt-regexp
 >        (save-excursion
 >  	(beginning-of-line)
 > -	(unless (looking-at comint-prompt-regexp)
 > -	  (re-search-backward comint-prompt-regexp nil t))
 >  	(comint-skip-prompt)
 >  	(point))
 >      ;; Use input fields.  Note that, unlike the behavior of
 > @@ -2278,7 +2276,10 @@ (defun comint-line-beginning-position ()
 >      ;; if there are two fields on a line, then the first one is the
 >      ;; prompt, and the second one is an input field, and is front-sticky
 >      ;; (as input fields should be).
 > -    (constrain-to-field (field-beginning) (line-end-position))))
 > +    (constrain-to-field (if (eq (field-at-pos (point)) 'output)
 > +			    (line-beginning-position)
 > +			  (field-beginning))
 > +			(line-end-position))))

 >  (defun comint-bol (&optional arg)
 >    "Go to the beginning of line, then skip past the prompt, if any.