From 2e4c2fe2787785a421f256541de642976e9bd90b Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Tue, 16 Sep 2014 17:07:12 -0700
Subject: [PATCH] Don't assume 'grep' supports GREP_OPTIONS.
The GREP_OPTIONS environment variable is planned to be marked
obsolescent in GNU grep, due to problems in its use, so stop
relying on it.
* progmodes/grep.el (grep-highlight-matches): Document this.
(grep-process-setup): Do not set GREP_OPTIONS.
(grep-compute-defaults): Use an explicit --color option if supported.
---
lisp/ChangeLog | 10 ++++++++++
lisp/progmodes/grep.el | 21 +++++++++++----------
2 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index bc514d29b10..d5054c0c9fc 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,13 @@
+2014-09-17 Paul Eggert <eggert@cs.ucla.edu>
+
+ Don't assume 'grep' supports GREP_OPTIONS.
+ The GREP_OPTIONS environment variable is planned to be marked
+ obsolescent in GNU grep, due to problems in its use, so stop
+ relying on it.
+ * progmodes/grep.el (grep-highlight-matches): Document this.
+ (grep-process-setup): Do not set GREP_OPTIONS.
+ (grep-compute-defaults): Use an explicit --color option if supported.
+
2014-09-16 Stefan Monnier <monnier@iro.umontreal.ca>
* msb.el (msb--make-keymap-menu, msb-menu-bar-update-buffers):
diff --git a/lisp/progmodes/grep.el b/lisp/progmodes/grep.el
index d60534074b9..47d92e70c5f 100644
--- a/lisp/progmodes/grep.el
+++ b/lisp/progmodes/grep.el
@@ -76,11 +76,10 @@ in grep buffers, so if you have globally disabled font-lock-mode,
you will not get highlighting.
This option sets the environment variable GREP_COLORS to specify
-markers for highlighting and GREP_OPTIONS to add the --color
-option in front of any explicit grep options before starting
-the grep.
+markers for highlighting and adds the --color option in front of
+any explicit grep options before starting the grep.
-When this option is `auto', grep uses `--color=auto' to highlight
+When this option is `auto', grep uses `--color' to highlight
matches only when it outputs to a terminal (when `grep' is the last
command in the pipe), thus avoiding the use of any potentially-harmful
escape sequences when standard output goes to a file or pipe.
@@ -96,7 +95,7 @@ To change the default value, use Customize or call the function
:type '(choice (const :tag "Do not highlight matches with grep markers" nil)
(const :tag "Highlight matches with grep markers" t)
(const :tag "Use --color=always" always)
- (const :tag "Use --color=auto" auto)
+ (const :tag "Use --color" auto)
(other :tag "Not Set" auto-detect))
:set 'grep-apply-setting
:version "22.1"
@@ -466,10 +465,6 @@ Set up `compilation-exit-message-function' and run `grep-setup-hook'."
;; `setenv' modifies `process-environment' let-bound in `compilation-start'
;; Any TERM except "dumb" allows GNU grep to use `--color=auto'
(setenv "TERM" "emacs-grep")
- (setenv "GREP_OPTIONS"
- (concat (getenv "GREP_OPTIONS")
- " --color=" (if (eq grep-highlight-matches 'always)
- "always" "auto")))
;; GREP_COLOR is used in GNU grep 2.5.1, but deprecated in later versions
(setenv "GREP_COLOR" "01;31")
;; GREP_COLORS is used in GNU grep 2.5.2 and later versions
@@ -569,7 +564,13 @@ This function is called from `compilation-filter-hook'."
(unless (and grep-command grep-find-command
grep-template grep-find-template)
(let ((grep-options
- (concat (if grep-use-null-device "-n" "-nH")
+ (concat (and grep-highlight-matches
+ (grep-probe grep-program
+ `(nil nil nil "--color" "x" ,null-device)
+ nil 1)
+ (if (eq grep-highlight-matches 'always)
+ "--color=always " "--color "))
+ (if grep-use-null-device "-n" "-nH")
(if (grep-probe grep-program
`(nil nil nil "-e" "foo" ,null-device)
nil 1)
--
2.39.5