Array equality treats undefined elements as equal however they got in there

- Fixes #786

lib/jasmine-core/jasmine.js

@@ -2879,14 +2879,22 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     var size = 0;
     // Recursively compare objects and arrays.
     // Compare array lengths to determine if a deep comparison is necessary.
-    if (className == '[object Array]' && a.length !== b.length) {
+    if (className == '[object Array]') {
-      result = false;
+      size = a.length;
+      if (size !== b.length) {
+        return false;
       }
 
-    if (result) {
+      while (size--) {
+        result = eq(a[size], b[size], aStack, bStack, customTesters);
+        if (!result) {
+          return false;
+        }
+      }
+    } else {
+
       // Objects with different constructors are not equivalent, but `Object`s
       // or `Array`s from different frames are.
-      if (className !== '[object Array]') {
       var aCtor = a.constructor, bCtor = b.constructor;
       if (aCtor !== bCtor && !(isFunction(aCtor) && aCtor instanceof aCtor &&
                                isFunction(bCtor) && bCtor instanceof bCtor)) {
@@ -2895,11 +2903,11 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     }
 
     // Deep compare objects.
-      var aKeys = keys(a), key;
+    var aKeys = keys(a, className == '[object Array]'), key;
     size = aKeys.length;
 
     // Ensure that both objects contain the same number of properties before comparing deep equality.
-      if (keys(b).length !== size) { return false; }
+    if (keys(b, className == '[object Array]').length !== size) { return false; }
 
     while (size--) {
       key = aKeys[size];
@@ -2910,15 +2918,14 @@ getJasmineRequireObj().matchersUtil = function(j$) {
         return false;
       }
     }
-    }
     // Remove the first object from the stack of traversed objects.
     aStack.pop();
     bStack.pop();
 
     return result;
 
-    function keys(obj) {
+    function keys(obj, isArray) {
-      return Object.keys ? Object.keys(obj) :
+      var allKeys = Object.keys ? Object.keys(obj) :
         (function(o) {
             var keys = [];
             for (var key in o) {
@@ -2928,6 +2935,19 @@ getJasmineRequireObj().matchersUtil = function(j$) {
             }
             return keys;
         })(obj);
+
+      if (!isArray) {
+        return allKeys;
+      }
+
+      var extraKeys = [];
+      for (var i in allKeys) {
+        if (!allKeys[i].match(/^[0-9]+$/)) {
+          extraKeys.push(key);
+        }
+      }
+
+      return extraKeys;
     }
 
     function has(obj, key) {

spec/core/matchers/matchersUtilSpec.js

@@ -54,6 +54,13 @@ describe("matchersUtil", function() {
       expect(jasmineUnderTest.matchersUtil.equals([1, 2], [1, 2])).toBe(true);
     });
 
+    it("passes for Arrays that are equivalent, with elements added by changing length", function() {
+      var foo = [];
+      foo.length = 1;
+
+      expect(jasmineUnderTest.matchersUtil.equals(foo, [undefined])).toBe(true);
+    });
+
     it("fails for Arrays that are not equivalent", function() {
       expect(jasmineUnderTest.matchersUtil.equals([1, 2], [1, 2, 3])).toBe(false);
     });

src/core/matchers/matchersUtil.js

@@ -161,14 +161,22 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     var size = 0;
     // Recursively compare objects and arrays.
     // Compare array lengths to determine if a deep comparison is necessary.
-    if (className == '[object Array]' && a.length !== b.length) {
+    if (className == '[object Array]') {
-      result = false;
+      size = a.length;
+      if (size !== b.length) {
+        return false;
       }
 
-    if (result) {
+      while (size--) {
+        result = eq(a[size], b[size], aStack, bStack, customTesters);
+        if (!result) {
+          return false;
+        }
+      }
+    } else {
+
       // Objects with different constructors are not equivalent, but `Object`s
       // or `Array`s from different frames are.
-      if (className !== '[object Array]') {
       var aCtor = a.constructor, bCtor = b.constructor;
       if (aCtor !== bCtor && !(isFunction(aCtor) && aCtor instanceof aCtor &&
                                isFunction(bCtor) && bCtor instanceof bCtor)) {
@@ -177,11 +185,11 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     }
 
     // Deep compare objects.
-      var aKeys = keys(a), key;
+    var aKeys = keys(a, className == '[object Array]'), key;
     size = aKeys.length;
 
     // Ensure that both objects contain the same number of properties before comparing deep equality.
-      if (keys(b).length !== size) { return false; }
+    if (keys(b, className == '[object Array]').length !== size) { return false; }
 
     while (size--) {
       key = aKeys[size];
@@ -192,15 +200,14 @@ getJasmineRequireObj().matchersUtil = function(j$) {
         return false;
       }
     }
-    }
     // Remove the first object from the stack of traversed objects.
     aStack.pop();
     bStack.pop();
 
     return result;
 
-    function keys(obj) {
+    function keys(obj, isArray) {
-      return Object.keys ? Object.keys(obj) :
+      var allKeys = Object.keys ? Object.keys(obj) :
         (function(o) {
             var keys = [];
             for (var key in o) {
@@ -210,6 +217,19 @@ getJasmineRequireObj().matchersUtil = function(j$) {
             }
             return keys;
         })(obj);
+
+      if (!isArray) {
+        return allKeys;
+      }
+
+      var extraKeys = [];
+      for (var i in allKeys) {
+        if (!allKeys[i].match(/^[0-9]+$/)) {
+          extraKeys.push(key);
+        }
+      }
+
+      return extraKeys;
     }
 
     function has(obj, key) {