* lisp/progmodes/grep.el (grep-mode): Fix last change.

Fixes: debbugs:8684

2 files changed, 7 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index a5af20b109b..a1ec897b2e2 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2011-05-21  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * progmodes/grep.el (grep-mode): Fix last change (bug#8684).
+
 2011-05-21  Glenn Morris  <rgm@gnu.org>
 
         * files.el (hack-local-variables-prop-line, hack-local-variables):
diff --git a/lisp/progmodes/grep.el b/lisp/progmodes/grep.el
index 3b819a149b2..04b54b1d662 100644
--- a/lisp/progmodes/grep.el
+++ b/lisp/progmodes/grep.el
@@ -698,7 +698,9 @@ This function is called from `compilation-filter-hook'."
        grep-hit-face)
   (set (make-local-variable 'compilation-error-regexp-alist)
        grep-regexp-alist)
-  (set (make-local-variable 'compilation-directory-matcher) nil)
+  ;; compilation-directory-matcher can't be nil, so we set it to a regexp that
+  ;; can never match.
+  (set (make-local-variable 'compilation-directory-matcher) "\\`a\\`")
   (set (make-local-variable 'compilation-process-setup-function)
        'grep-process-setup)
   (set (make-local-variable 'compilation-disable-input) t)