Re: [david.hansen@gmx.net: Re: comint's directory tracking doesn't understand \( or \)]

[Chong Yidong <cyd@stupidchicken.com>]

David Hansen <david.hansen@gmx.net> wrote:

> The string gets still splitted at members of
> `comint-delimiter-argument-list' (note that it's buffer local) no
> matter if they are escaped or not.
>
> I have to admit that it probably can be fixed with far less than a
> 200 line patch but I'm not willing to touch these regexps and i
> don't think it will result in anything "safer".

I think there is an easy way to get around this difficulty: once
backslash-escaped characters have been identified, put a text property
on the string saying that character is literal, then make
comint-delim-arg avoid splitting when such a text property is present.
Here is a patch to implement this.  I can verify that it solves the
original bug.

As far as safety goes, I think it is a little safer than the other
candidate patch, if only because it's simpler to read.

*** /home/cyd/emacs/lisp/comint.el.~1.358.~	2007-02-27 19:43:48.000000000 -0500
--- /home/cyd/emacs/lisp/comint.el	2007-03-10 15:15:40.000000000 -0500
***************
*** 1356,1367 ****
        (while (< pos len)
  	(let ((char (aref arg pos))
  	      (start pos))
! 	  (if (memq char comint-delimiter-argument-list)
  	      (while (and (< pos len) (eq (aref arg pos) char))
  		(setq pos (1+ pos)))
  	    (while (and (< pos len)
! 			(not (memq (aref arg pos)
! 				   comint-delimiter-argument-list)))
  	      (setq pos (1+ pos))))
  	  (setq args (cons (substring arg start pos) args))))
        args)))
--- 1356,1371 ----
        (while (< pos len)
  	(let ((char (aref arg pos))
  	      (start pos))
! 	  (if (and (memq char comint-delimiter-argument-list)
! 		   ;; Ignore backslash-escaped characters.
! 		   (not (get-text-property pos 'literal arg)))
  	      (while (and (< pos len) (eq (aref arg pos) char))
  		(setq pos (1+ pos)))
  	    (while (and (< pos len)
! 			(not (and (memq (aref arg pos)
! 					comint-delimiter-argument-list)
! 				  (not (get-text-property
! 					pos 'literal arg)))))
  	      (setq pos (1+ pos))))
  	  (setq args (cons (substring arg start pos) args))))
        args)))
***************
*** 1381,1404 ****
    ;; The third matches '-quoted strings.
    ;; The fourth matches `-quoted strings.
    ;; This seems to fit the syntax of BASH 2.0.
!   (let* ((first (if (if (fboundp 'w32-shell-dos-semantics)
! 			(w32-shell-dos-semantics))
! 		    "[^ \n\t\"'`]+\\|"
! 		  "[^ \n\t\"'`\\]+\\|\\\\[\"'`\\ \t]+\\|"))
  	 (argpart (concat first
  			  "\\(\"\\([^\"\\]\\|\\\\.\\)*\"\\|\
  '[^']*'\\|\
  `[^`]*`\\)"))
  	 (args ()) (pos 0)
  	 (count 0)
  	 beg str quotes)
      ;; Build a list of all the args until we have as many as we want.
      (while (and (or (null mth) (<= count mth))
  		(string-match argpart string pos))
        (if (and beg (= pos (match-beginning 0)))
  	  ;; It's contiguous, part of the same arg.
  	  (setq pos (match-end 0)
! 		quotes (or quotes (match-beginning 1)))
  	;; It's a new separate arg.
  	(if beg
  	    ;; Put the previous arg, if there was one, onto ARGS.
--- 1385,1414 ----
    ;; The third matches '-quoted strings.
    ;; The fourth matches `-quoted strings.
    ;; This seems to fit the syntax of BASH 2.0.
!   (let* ((backslash-escape (not (and (fboundp 'w32-shell-dos-semantics)
! 				     (w32-shell-dos-semantics))))
! 	 (first (if backslash-escape
! 		    "[^ \n\t\"'`\\]\\|\\(\\\\.\\)\\|"
! 		  "[^ \n\t\"'`]+\\|"))
  	 (argpart (concat first
  			  "\\(\"\\([^\"\\]\\|\\\\.\\)*\"\\|\
  '[^']*'\\|\
  `[^`]*`\\)"))
+ 	 (quote-subexpr (if backslash-escape 2 1))
  	 (args ()) (pos 0)
  	 (count 0)
  	 beg str quotes)
      ;; Build a list of all the args until we have as many as we want.
      (while (and (or (null mth) (<= count mth))
  		(string-match argpart string pos))
+       (and backslash-escape
+ 	   (match-beginning 1)
+ 	   (put-text-property (match-beginning 1) (match-end 1)
+ 			      'literal t string))
        (if (and beg (= pos (match-beginning 0)))
  	  ;; It's contiguous, part of the same arg.
  	  (setq pos (match-end 0)
! 		quotes (or quotes (match-beginning quote-subexpr)))
  	;; It's a new separate arg.
  	(if beg
  	    ;; Put the previous arg, if there was one, onto ARGS.
***************
*** 1406,1412 ****
  		  args (if quotes (cons str args)
  			 (nconc (comint-delim-arg str) args))))
  	(setq count (length args))
! 	(setq quotes (match-beginning 1))
  	(setq beg (match-beginning 0))
  	(setq pos (match-end 0))))
      (if beg
--- 1416,1422 ----
  		  args (if quotes (cons str args)
  			 (nconc (comint-delim-arg str) args))))
  	(setq count (length args))
! 	(setq quotes (match-beginning quote-subexpr))
  	(setq beg (match-beginning 0))
  	(setq pos (match-end 0))))
      (if beg