Re: weird bug with `Russian-computer'?

[Juri Linkov <juri@jurta.org>]

> With the `Russian-computer' input method, S-/ combination produces a comma
> (instead of a question mark with standard English.)  That is OK and the
> way it should be.

Perhaps you have a US keyboard layout with `?' on the same key as `/'.
Finnish keyboards have quite a different layout where `?' is on the
same key as `+', and it is produced by `S-+'.  Other keyboards have
other layouts, but anyhow I understand how to reproduce the problem.
What is essential here is to press shift with the `?' key, because the
`russian-computer' input method maps `?' to `,'.

> However, when I start incremental search, the key works as in
> English, while the rest of the keyboard keeps producing Russian
> letters etc.

The root of the problem is in `isearch-mode-map' which binds `?' to
`isearch-*-char'.  When you type a key corresponding to `?' with
the input method, `isearch-*-char' intercepts it and interprets as
the regexp special character `?'.

The following patch fixes this problem by sending the input character
to `isearch-process-search-char' which takes care of processing the
character according to the current input method.  Also a new condition
was added before processing a regexp character.  If an input method is
active, it processes a regexp character only if a typed character is
the same with and without an input method, so that all input methods
that don't redefine regexp characters won't be affected.

Index: lisp/isearch.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/isearch.el,v
retrieving revision 1.263
diff -c -r1.263 isearch.el
*** lisp/isearch.el	23 Apr 2005 15:38:07 -0000	1.263
--- lisp/isearch.el	4 Jul 2005 00:35:07 -0000
***************
*** 1413,1420 ****
  If optional TO-BARRIER non-nil, ignore previous matches and go exactly to the
  barrier."
    ;; (eq (not a) (not b)) makes all non-nil values equivalent
!   (when (and isearch-regexp (eq (not (isearch-backslash isearch-string))
! 				(not want-backslash))
  	     ;; We have to check 2 stack frames because the last might be
  	     ;; invalid just because of a backslash.
  	     (or (not isearch-error)
--- 1423,1435 ----
  If optional TO-BARRIER non-nil, ignore previous matches and go exactly to the
  barrier."
    ;; (eq (not a) (not b)) makes all non-nil values equivalent
!   (when (and isearch-regexp
! 	     (or (not current-input-method)
! 		 (let ((qchar (quail-find-key last-command-char)))
! 		   (or (eq qchar t)
! 		       (equal (car-safe qchar) (string last-command-char)))))
! 	     (eq (not (isearch-backslash isearch-string))
! 		 (not want-backslash))
  	     ;; We have to check 2 stack frames because the last might be
  	     ;; invalid just because of a backslash.
  	     (or (not isearch-error)
***************
*** 1458,1464 ****
  			   (max last-other-end isearch-barrier)
  			 (min last-other-end isearch-barrier)))
  	    (setq isearch-adjusted t))))))
!   (isearch-process-search-char last-command-char))
  
  ;; * and ? are special when not preceded by \.
  (defun isearch-*-char ()
--- 1473,1479 ----
  			   (max last-other-end isearch-barrier)
  			 (min last-other-end isearch-barrier)))
  	    (setq isearch-adjusted t))))))
!   (isearch-printing-char))
  
  ;; * and ? are special when not preceded by \.
  (defun isearch-*-char ()

Index: lisp/international/isearch-x.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/international/isearch-x.el,v
retrieving revision 1.19
diff -c -r1.19 isearch-x.el
*** lisp/international/isearch-x.el	13 May 2005 06:03:45 -0000	1.19
--- lisp/international/isearch-x.el	4 Jul 2005 00:35:19 -0000
***************
*** 96,104 ****
  
  ;;;###autoload
  (defun isearch-process-search-multibyte-characters (last-char)
!   (if (eq this-command 'isearch-printing-char)
        (let ((overriding-terminal-local-map nil)
! 	    (prompt (concat (isearch-message-prefix)))
  	    (minibuffer-local-map isearch-minibuffer-local-map)
  	    str)
  	(if isearch-input-method-function
--- 96,105 ----
  
  ;;;###autoload
  (defun isearch-process-search-multibyte-characters (last-char)
!   (if (memq this-command '(isearch-printing-char
! 			   isearch-*-char isearch-}-char isearch-|-char))
        (let ((overriding-terminal-local-map nil)
! 	    (prompt (isearch-message-prefix))
  	    (minibuffer-local-map isearch-minibuffer-local-map)
  	    str)
  	(if isearch-input-method-function

-- 
Juri Linkov
http://www.jurta.org/emacs/