From 28aea66104c24b78f7c3620a0f876703acc14dfe Mon Sep 17 00:00:00 2001
From: Pierre-Yves Gerardy <py@py.gy>
Date: Sun, 12 Feb 2017 23:01:46 +0100
Subject: [PATCH 1/2] Also update .lastIndex on natively sticky regexps

---
 src/xregexp.js                  |  2 +-
 tests/spec/s-xregexp-methods.js | 56 ++++++++++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/src/xregexp.js b/src/xregexp.js
index c4f13f12..c78dd7eb 100644
--- a/src/xregexp.js
+++ b/src/xregexp.js
@@ -857,7 +857,7 @@ XRegExp.exec = function(str, regex, pos, sticky) {
         match = null;
     }
 
-    if (regex.global) {
+    if (regex.global || regex.sticky && sticky !== false) {
         regex.lastIndex = match ? r2.lastIndex : 0;
     }
 
diff --git a/tests/spec/s-xregexp-methods.js b/tests/spec/s-xregexp-methods.js
index 432289c1..f519ccaf 100644
--- a/tests/spec/s-xregexp-methods.js
+++ b/tests/spec/s-xregexp-methods.js
@@ -260,7 +260,7 @@ describe('XRegExp.exec()', function() {
         expect(XRegExp.exec('abcxdef', /(a)/)).toEqualMatch(['a', 'a']);
     });
 
-    it('should not modify the lastIndex of a nonglobal regex', function() {
+    it('should not modify the lastIndex of a nonglobal, non-sticky regex', function() {
         var regexX = /x/;
         var str = 'abcxdef';
         XRegExp.exec(str, regexX);
@@ -307,6 +307,60 @@ describe('XRegExp.exec()', function() {
         expect(regex.lastIndex).toBe(0);
     });
 
+    if (hasNativeY) {
+        it('should not modify the lastIndex of a sticky regex when exec is invoked in explicitly non-sticky mode', function() {
+            var regexX = new RegExp('x', 'y');
+            var str = 'abcxdef';
+            XRegExp.exec(str, regexX, 0, false);
+
+            expect(regexX.lastIndex).toBe(0);
+
+            regexX.lastIndex = 5;
+            XRegExp.exec(str, regexX, 0, false);
+
+            expect(regexX.lastIndex).toBe(5);
+
+            var regexZ = new RegExp('z', 'y');
+            regexZ.lastIndex = 5;
+            XRegExp.exec(str, regexZ, 0, false);
+
+            expect(regexZ.lastIndex).toBe(5);
+        });
+
+        it('should set the lastIndex of a sticky regex to the end position of a successful match', function() {
+            var regex1 = new RegExp('x', 'y');
+            XRegExp.exec('abcxdef', regex1, 3);
+
+            expect(regex1.lastIndex).toBe(4);
+
+            var regex2 = new RegExp('x', 'y');
+            XRegExp.exec('abcxdef', regex2, 3, 'sticky');
+
+            expect(regex2.lastIndex).toBe(4);
+        });
+
+        it('should set the lastIndex of a sticky regex to 0 after a failed match', function() {
+            var regexZ = new RegExp('z', 'y');
+            regexZ.lastIndex = 1;
+            XRegExp.exec('abcxdef', regexZ);
+
+            expect(regexZ.lastIndex).toBe(0);
+
+            var regexX = new RegExp('x', 'y');
+            regexX.lastIndex = 1;
+            XRegExp.exec('abcxdef', regexX, 2, 'sticky');
+
+            expect(regexX.lastIndex).toBe(0);
+        });
+
+        it('should not increment the lastIndex of a sticky regex after a zero-length match', function() {
+            var regex = new RegExp('', 'y');
+            XRegExp.exec('abc', regex);
+
+            expect(regex.lastIndex).toBe(0);
+        });
+    }
+
     it('should convert any nonstring subject to a string', function() {
         var values = [
             undefined,

From 8a341c32f4630a4fb9e6d2695e60677d92c07e28 Mon Sep 17 00:00:00 2001
From: Pierre-Yves Gerardy <py@py.gy>
Date: Sun, 12 Feb 2017 23:20:13 +0100
Subject: [PATCH 2/2] build

---
 xregexp-all.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xregexp-all.js b/xregexp-all.js
index e680d329..fe017a98 100644
--- a/xregexp-all.js
+++ b/xregexp-all.js
@@ -3503,7 +3503,7 @@ XRegExp.exec = function(str, regex, pos, sticky) {
         match = null;
     }
 
-    if (regex.global) {
+    if (regex.global || regex.sticky && sticky !== false) {
         regex.lastIndex = match ? r2.lastIndex : 0;
     }