* progmodes/grep.el (grep-regexp-alist): Use more-accurate regexp.

Do not match file names that end in '/', as they cannot be 'grep'
hits nowadays.  This prevents confusion when 'grep -r' reports a
match in a file whose basename is ':12345:'.  Conversely, do not
require exactly the same sequence of spaces and tabs after both
colons, and allow spaces or tabs before the second colon, as per
the POSIX spec for 'grep' output.

2 files changed, 15 insertions, 10 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 4c4941d982d..8586d59b3ad 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,13 @@
+2014-09-26  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * progmodes/grep.el (grep-regexp-alist): Use more-accurate regexp.
+        Do not match file names that end in '/', as they cannot be 'grep'
+        hits nowadays.  This prevents confusion when 'grep -r' reports a
+        match in a file whose basename is ':12345:'.  Conversely, do not
+        require exactly the same sequence of spaces and tabs after both
+        colons, and allow spaces or tabs before the second colon, as per
+        the POSIX spec for 'grep' output.
+
 2014-09-26  Leo Liu  <sdl.web@gmail.com>
 
         Add cl-parse-integer based on parse-integer (Bug#18557)
diff --git a/lisp/progmodes/grep.el b/lisp/progmodes/grep.el
index 47d92e70c5f..fd48adc70c6 100644
--- a/lisp/progmodes/grep.el
+++ b/lisp/progmodes/grep.el
@@ -343,16 +343,11 @@ Notice that using \\[next-error] or \\[compile-goto-error] modifies
 ;;;###autoload
 (defconst grep-regexp-alist
   '(
-    ;; Rule to match column numbers is commented out since no known grep
-    ;; produces them
-    ;; ("^\\(.+?\\)\\(:[ \t]*\\)\\([1-9][0-9]*\\)\\2\\(?:\\([1-9][0-9]*\\)\\(?:-\\([1-9][0-9]*\\)\\)?\\2\\)?"
-    ;;  1 3 (4 . 5))
-    ;; Note that we want to use as tight a regexp as we can to try and
-    ;; handle weird file names (with colons in them) as well as possible.
-    ;; E.g. we use [1-9][0-9]* rather than [0-9]+ so as to accept ":034:"
-    ;; in file names.
-    ("^\\(.+?\\)\\(:[ \t]*\\)\\([1-9][0-9]*\\)\\2"
-     1 3
+    ;; Use a tight regexp to handle weird file names (with colons
+    ;; in them) as well as possible.  E.g., use [1-9][0-9]* rather
+    ;; than [0-9]+ so as to accept ":034:" in file names.
+    ("^\\(.*?[^/\n]\\):[ \t]*\\([1-9][0-9]*\\)[ \t]*:"
+     1 2
      ;; Calculate column positions (col . end-col) of first grep match on a line
      ((lambda ()
         (when grep-highlight-matches