From 6d51f41cd867ff081d83099900ef0702a11df1a1 Mon Sep 17 00:00:00 2001
From: elitvyakov <elitvykaov@solit-clouds.ru>
Date: Thu, 24 Nov 2016 13:52:17 +0300
Subject: [PATCH] es5-shim: #412 fix groups with quantifiers preventing its
 exercise

---
 es5-shim.js | 85 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 78 insertions(+), 7 deletions(-)

diff --git a/es5-shim.js b/es5-shim.js
index bad9c942..72c9a29a 100644
--- a/es5-shim.js
+++ b/es5-shim.js
@@ -1882,23 +1882,94 @@
         StringPrototype.replace = function replace(searchValue, replaceValue) {
             var isFn = isCallable(replaceValue);
             var hasCapturingGroups = isRegex(searchValue) && (/\)[*?]/).test(searchValue.source);
+            var extendedGroups = getExtendedGroups(searchValue);
+
             if (!isFn || !hasCapturingGroups) {
                 return str_replace.call(this, searchValue, replaceValue);
             } else {
                 var wrappedReplaceValue = function (match) {
-                    var length = arguments.length;
-                    var originalLastIndex = searchValue.lastIndex;
-                    searchValue.lastIndex = 0;
-                    var args = searchValue.exec(match) || [];
-                    searchValue.lastIndex = originalLastIndex;
-                    pushCall(args, arguments[length - 2], arguments[length - 1]);
-                    return replaceValue.apply(this, args);
+                    var groups = ArrayPrototype.slice.call(arguments, 1, -2);
+
+                    for (var i = 0; i < groups.length; i++) {
+                        var argumentIndex = i + 1;
+                        if (groups[i] === '' && extendedGroups[i].mayBeMissing) {
+                            arguments[argumentIndex] = undefined;
+                        }
+                    }
+
+                    return replaceValue.apply(this, arguments);
                 };
                 return str_replace.call(this, searchValue, wrappedReplaceValue);
             }
         };
     }
 
+    /**
+     * @param regexp {RegExp}
+     * @returns {Object[]} groups
+     *  @return {number} groups[].number        - The number of group.
+     *  @return {boolean} groups[].mayBeMissing - The group with quantifiers preventing its exercise, the matched text
+     *                                            for a capturing group is now undefined instead of an empty string.
+     *                                            The group without quantifiers, may be empty string.
+     *  @return {boolean} groups[].isResulting  - The groups with ?:, ?=, ?! are non-capturing groups.
+     */
+    function getExtendedGroups (regexp) {
+        var source = regexp.source;
+        var result = [];
+        var prevFirst,
+            prevSecond,
+            nextFirst,
+            nextSecond;
+        var groupNumberCounter = 0;
+
+        for (var charIndex in source) {
+            var char = source[+charIndex];
+            prevFirst = source[+charIndex - 1] || null;
+            prevSecond = source[+charIndex - 2] || null;
+            nextFirst = source[+charIndex + 1] || null;
+            nextSecond = source[+charIndex + 2] || null;
+
+            if (char === '(') {
+                if (prevFirst && prevFirst === '\\') continue;
+
+                if (nextFirst && nextFirst === '?' && nextSecond && nextSecond === ':' ||
+                    nextFirst && nextFirst === '?' && nextSecond && nextSecond === '=' ||
+                    nextFirst && nextFirst === '?' && nextSecond && nextSecond === '!') {
+                    result.push({
+                        number: ++groupNumberCounter,
+                        mayBeMissing: true,
+                        isResulting: false
+                    });
+                    continue;
+                }
+
+                result.push({
+                    number: ++groupNumberCounter,
+                    mayBeMissing: false,
+                    isResulting: true
+                });
+            }
+
+            if (char === ')') {
+                var groupIndex = groupNumberCounter - 1;
+
+                if (prevFirst && prevFirst === '\\') continue;
+
+                if (result[groupIndex] && !result[groupIndex].isResulting) {
+                    result.splice(groupIndex, 1);
+                    groupNumberCounter = --groupNumberCounter;
+                    continue;
+                }
+
+                if (nextFirst && nextFirst === '?' || nextFirst === '*') {
+                    result[groupIndex].mayBeMissing = true;
+                }
+            }
+        }
+
+        return result;
+    }
+
     // ECMA-262, 3rd B.2.3
     // Not an ECMAScript standard, although ECMAScript 3rd Edition has a
     // non-normative section suggesting uniform semantics and it should be