From 67e450115aa85c86fcfeaa356143f3d5d2487d66 Mon Sep 17 00:00:00 2001
From: Justin Viiret <justin.viiret@intel.com>
Date: Thu, 28 Jul 2016 12:38:26 +1000
Subject: [PATCH] parser: ignore \E that is not preceded by \Q

This conforms to PCRE's behaviour, where an isolated \E that is not
preceded by \Q is ignored.
---
 src/parser/Parser.rl            | 5 ++---
 unit/hyperscan/bad_patterns.txt | 1 -
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/parser/Parser.rl b/src/parser/Parser.rl
index 9bd4d96d..53130ddf 100644
--- a/src/parser/Parser.rl
+++ b/src/parser/Parser.rl
@@ -1226,9 +1226,8 @@ unichar readUtf8CodePoint4c(const u8 *ts) {
               '\\Q' => {
                   fgoto readQuotedLiteral;
               };
-              '\\E' => {
-                  throw LocatedParseError("Unmatched \\E");
-              };
+              # An \E that is not preceded by a \Q is ignored
+              '\\E' => { /* noop */ };
               # Match any character
               '\.' => {
                   currentSeq->addComponent(generateComponent(CLASS_ANY, false, mode));
diff --git a/unit/hyperscan/bad_patterns.txt b/unit/hyperscan/bad_patterns.txt
index 9fc3a413..1a33210d 100644
--- a/unit/hyperscan/bad_patterns.txt
+++ b/unit/hyperscan/bad_patterns.txt
@@ -32,7 +32,6 @@
 31:/\B/W #\B unsupported in UCP mode at index 0.
 32:/foo(?{print "Hello world\n";})bar/ #Embedded code is not supported at index 3.
 33:/the (\S+)(?{ $color = $^N }) (\S+)(?{ $animal = $^N })/i #Embedded code is not supported at index 9.
-34:/foobar\E/s #Unmatched \E at index 6.
 35:/\X/8 #\X unsupported at index 0.
 36:/\B+/ #Invalid repeat at index 2.
 37:/\B?/ #Invalid repeat at index 2.