From 626eba1b8a7ccd839fe96ee94800b059c5981461 Mon Sep 17 00:00:00 2001
From: Paul Eggert <address@hidden>
Date: Fri, 27 Jun 2014 12:31:29 -0700
Subject: [PATCH] grep: with -E, unmatched ')' matches itself

Problem reported by Nathan Weeks in: http://bugs.gnu.org/17856
* src/grep.c (Ecompile): Also specify RE_UNMATCHED_RIGHT_PAREN_ORD.
* doc/grep.texi (Fundamental Structure), NEWS: Document this.
* tests/ere.tests: Add a couple of tests for this.
* tests/spencer1.tests: Fix exit status.
---
 NEWS                 | 4 ++++
 doc/grep.texi        | 1 +
 src/grep.c           | 4 +++-
 tests/ere.tests      | 3 +++
 tests/spencer1.tests | 2 +-
 5 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index 1af3def..550bf4c 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,10 @@ GNU grep NEWS                                    -*- outline -*-
 
   Performance has improved for very long strings in patterns.
 
+** Bug fixes
+
+  grep -E rejected unmatched ')', instead of treating it like '\)'.
+  [bug present since "the beginning"]
 
 * Noteworthy changes in release 2.20 (2014-06-03) [stable]
 
diff --git a/doc/grep.texi b/doc/grep.texi
index c9417e5..10cc2e4 100644
--- a/doc/grep.texi
+++ b/doc/grep.texi
@@ -1208,6 +1208,7 @@ Repetition takes precedence over concatenation,
 which in turn takes precedence over alternation.
 A whole expression may be enclosed in parentheses
 to override these precedence rules and form a subexpression.
+An unmatched @samp{)} matches just itself.
 
 @node Character Classes and Bracket Expressions
 @section Character Classes and Bracket Expressions
diff --git a/src/grep.c b/src/grep.c
index 7c0f8a8..f2fca74 100644
--- a/src/grep.c
+++ b/src/grep.c
@@ -1638,7 +1638,9 @@ Gcompile (char const *pattern, size_t size)
 static void
 Ecompile (char const *pattern, size_t size)
 {
-  GEAcompile (pattern, size, RE_SYNTAX_POSIX_EGREP | RE_NO_EMPTY_RANGES);
+  GEAcompile (pattern, size,
+              (RE_SYNTAX_POSIX_EGREP | RE_NO_EMPTY_RANGES
+               | RE_UNMATCHED_RIGHT_PAREN_ORD));
 }
 
 static void
diff --git a/tests/ere.tests b/tests/ere.tests
index e0aad2a..8ab6510 100644
--- a/tests/ere.tests
+++ b/tests/ere.tests
@@ -215,3 +215,6 @@
 address@hidden|address@hidden
 address@hidden@ab
 address@hidden@ESIZE
+0@)@)
+1@)@x
address@hidden()\((a\())(b))@()(a()b)
diff --git a/tests/spencer1.tests b/tests/spencer1.tests
index 36c0b9e..50581e8 100644
--- a/tests/spencer1.tests
+++ b/tests/spencer1.tests
@@ -59,7 +59,7 @@
 address@hidden(address@hidden
 address@hidden(address@hidden((b
 address@hidden@a\x
address@hidden)@-
address@hidden)@-
 2@(address@hidden
 0@((a))@abc
 0@(a)b(c)@abc
-- 
1.9.3