From: Noam Postavsky <npostavs@users.sourceforge.net>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 19350@debbugs.gnu.org, Demi Obenour <demiobenour@gmail.com>
Subject: bug#19350: #19350 24.4; Incorrect quoting of %-signs for Windows command shell
Date: Mon, 3 Oct 2016 14:47:37 -0400 [thread overview]
Message-ID: <CAM-tV-9q6R32UcQ2na616F+dX3KfJ7BfR3ZGTzkUCLnO5wJQ9w@mail.gmail.com> (raw)
In-Reply-To: <83twemf550.fsf@gnu.org>
[-- Attachment #1: Type: text/plain, Size: 1354 bytes --]
On Mon, Aug 15, 2016 at 11:01 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> From my POV, as long as Emacs itself doesn't produce such shell
> commands and/or environment variables for any of its features,
> avoiding this becomes user's responsibility, just like when working at
> the shell prompt. Of course, if we can find a reliable solution to
> the problem that doesn't take away features, that'd be better,
So I have been thinking about this. As far as I can tell, the %CD:~,0%
hack is the only way to solve it. We can make it conditional on having
command extensions enabled, see attached.
The probing command I used for the default value for
w32-shell-command-extensions causes an error while dumping ("Searching
for program: No such file or directory,
C:/Users/npostavs/src/emacs/emacs-25/nt/cmdproxy.exe") so I've
commented it out for now. With this patch,
(let ((w32-shell-command-extensions t)
(process-environment (cl-list* "ca^=with-caret"
"ca=without-caret"
process-environment)))
(insert (shell-command-to-string
(format "echo %s %s %s"
"%ca%"
(shell-quote-argument "%ca%")
"%%CD:~,0%ca%%CD:~,0%"))))
gives
without-caret "%ca%" %ca%
If this approach makes sense I can fix up the patch.
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diff --git i/lisp/subr.el w/lisp/subr.el
index e9e19d3..1d7d0dd 100644
--- i/lisp/subr.el
+++ w/lisp/subr.el
@@ -2753,15 +2753,31 @@ shell-quote-argument
"\\1\\1\\\\\""
argument)))
- (if (string-match "[%!\"]" argument)
- (concat
- "^\""
- (replace-regexp-in-string
- "\\([%!()\"<>&|^]\\)"
- "^\\1"
- argument)
- "^\"")
- (concat "\"" argument "\"")))
+ ;; cmd.exe performs %var% expansion before anything else, so there
+ ;; is no way escape '%'s (escaping with '^' *appears* to work, but
+ ;; that's only because variables with carets in the name are
+ ;; rare). If "Command Extensions" are enabled, it's possible to
+ ;; work around this limitation by appending "%CD:~,0%" to each
+ ;; '%'; it expands to the empty string and stops the preceding '%'
+ ;; from being interpreted as the beginning of a variable name.
+ (cond
+ ((and w32-shell-command-extensions (string-match "%" argument))
+ (concat
+ "^\""
+ (replace-regexp-in-string
+ "\\([!()\"<>&|^]\\)"
+ "^\\1"
+ (replace-regexp-in-string "%" "%%CD:~,0%" argument t t))
+ "^\""))
+ ((string-match "[%!\"]" argument)
+ (concat
+ "^\""
+ (replace-regexp-in-string
+ "\\([%!()\"<>&|^]\\)"
+ "^\\1"
+ argument)
+ "^\""))
+ (t (concat "\"" argument "\""))))
(t
(if (equal argument "")
diff --git i/lisp/w32-vars.el w/lisp/w32-vars.el
index c9317e4..3e76a86 100644
--- i/lisp/w32-vars.el
+++ w/lisp/w32-vars.el
@@ -65,6 +65,13 @@ w32-list-proportional-fonts
:type '(repeat string)
:group 'w32))
+(unless (eq system-type 'cygwin)
+ (defcustom w32-shell-command-extensions nil ;; (equal (shell-command-to-string "echo %%CD:~,0%") "%\n")
+ "If non-nil, assume the shell supports \"Command Extensions\".
+This is used by `shell-quote-argument' to safely escape \"%\"."
+ :type 'boolean
+ :group 'w32))
+
;; Want "menu" custom type for this.
(defcustom w32-fixed-font-alist
'("Font menu"
next prev parent reply other threads:[~2016-10-03 18:47 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-11 18:43 bug#19350: 24.4; Incorrect quoting of %-signs for Windows command shell Demetrios Obenour
2016-08-10 13:00 ` bug#19350: #19350 " Noam Postavsky
2016-08-10 16:11 ` Eli Zaretskii
2016-08-11 23:11 ` Demi Obenour
2016-08-12 0:41 ` npostavs
[not found] ` <CAJEMUN_nkRgwCF7h03x=_jdHDLGqC+DBk0=3NNJhZTx5woW8gg@mail.gmail.com>
[not found] ` <CAJEMUN-HMMJu1FTDrKEmn_8nOaMhDeE8Te2JuE7jVdvuqLtbNQ@mail.gmail.com>
2016-08-15 0:44 ` Demi Obenour
2016-08-15 3:13 ` npostavs
2016-08-15 15:01 ` Eli Zaretskii
2016-08-18 2:02 ` Demi Obenour
2016-08-18 2:21 ` Noam Postavsky
2016-08-18 11:54 ` Demi Obenour
2016-08-18 12:07 ` Noam Postavsky
2016-08-18 14:17 ` Eli Zaretskii
2016-10-03 18:47 ` Noam Postavsky [this message]
2016-10-03 19:15 ` Eli Zaretskii
[not found] ` <CAJEMUN9xcizd9rNYiZueg4gjRAcPxh4V_JZdaSt5jr-P4LRe-A@mail.gmail.com>
2016-10-03 19:38 ` Demi Obenour
2018-02-09 0:17 ` Noam Postavsky
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