Don't overwrite MatchersUtil methods with ones that were added to Array.prototype, esp. contains

Fixes #1849.

lib/jasmine-core/jasmine.js

@@ -2810,7 +2810,9 @@ getJasmineRequireObj().asymmetricEqualityTesterArgCompatShim = function(j$) {
 
     for (i = 0; i < props.length; i++) {
       k = props[i];
-      if (k !== 'length') {
+      // Skip length (dealt with above), and anything that collides with
+      // MatchesUtil e.g. an Array.prototype.contains method added by user code
+      if (k !== 'length' && !self[k]) {
         copy(self, Array.prototype, k);
       }
     }

spec/core/asymmetricEqualityTesterArgCompatShimSpec.js

@@ -36,7 +36,6 @@ describe('asymmetricEqualityTesterArgCompatShim', function() {
   it('provides properties of Array.prototype', function() {
     var keys = [
         'concat',
-        'constructor',
         'every',
         'filter',
         'forEach',
@@ -55,8 +54,6 @@ describe('asymmetricEqualityTesterArgCompatShim', function() {
         'some',
         'sort',
         'splice',
-        'toLocaleString',
-        'toString',
         'unshift'
       ],
       optionalKeys = [
@@ -98,4 +95,49 @@ describe('asymmetricEqualityTesterArgCompatShim', function() {
       }
     }
   });
+
+  describe('When Array.prototype additions collide with MatchersUtil methods', function() {
+    function keys() {
+      return [
+        'contains',
+        'buildFailureMessage',
+        'asymmetricDiff_',
+        'asymmetricMatch_',
+        'equals',
+        'eq_'
+      ];
+    }
+
+    beforeEach(function() {
+      keys().forEach(function(k) {
+        if (Array.prototype[k]) {
+          console.log(Array.prototype[k].toString());
+        }
+        expect(Array.prototype[k])
+          .withContext('Array.prototype already had ' + k)
+          .toBeUndefined();
+        Array.prototype[k] = function() {};
+      });
+    });
+
+    afterEach(function() {
+      keys().forEach(function(k) {
+        delete Array.prototype[k];
+      });
+    });
+
+    it('uses the MatchersUtil methods', function() {
+      var matchersUtil = new jasmineUnderTest.MatchersUtil({}),
+        shim = jasmineUnderTest.asymmetricEqualityTesterArgCompatShim(
+          matchersUtil,
+          []
+        );
+
+      keys().forEach(function(k) {
+        expect(shim[k])
+          .withContext(k + ' was overwritten')
+          .toBe(jasmineUnderTest.MatchersUtil.prototype[k]);
+      });
+    });
+  });
 });

src/core/asymmetricEqualityTesterArgCompatShim.js

@@ -66,7 +66,9 @@ getJasmineRequireObj().asymmetricEqualityTesterArgCompatShim = function(j$) {
 
     for (i = 0; i < props.length; i++) {
       k = props[i];
-      if (k !== 'length') {
+      // Skip length (dealt with above), and anything that collides with
+      // MatchesUtil e.g. an Array.prototype.contains method added by user code
+      if (k !== 'length' && !self[k]) {
         copy(self, Array.prototype, k);
       }
     }