Emacs won't assume grep supports GREP_OPTIONS

This upstream patch has been added:

  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.

Origin: upstream, commit: 2e4c2fe2787785a421f256541de642976e9bd90b
Bug: http://debbugs.gnu.org/19247
Bug-Debian: http://bugs.debian.org/793741
Added-by: Rob Browning <rlb@defaultvalue.org>

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index eb31d5fc2feee167fa0bfe606bc3cbcfc2453d5e..7345c6ac5b52d7ae7b97b38fd246e798d7514faf 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1165,6 +1165,16 @@
        count the whole visible buffer.  Correctly convert the body-height
        to pixel size for window-text-pixel-size (Bug#18498).
 
+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.
+
 2014-09-14  Glenn Morris  <rgm@gnu.org>
 
        * image.el (image-multi-frame-p): Fix thinko - do not force

diff --git a/lisp/progmodes/grep.el b/lisp/progmodes/grep.el
index d4caf48e089f53df526aede4d007f0bf5a4524ce..0e8c214aafbba461346836b9929d99c0c9e52893 100644 (file)
--- a/lisp/progmodes/grep.el
+++ b/lisp/progmodes/grep.el
@@ -77,11 +77,10 @@ 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.
@@ -97,7 +96,7 @@ 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"
@@ -467,10 +466,6 @@ 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
@@ -570,7 +565,13 @@ 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)