Fix regression with handling of $break inside Array#inject. [close #162]

Author: savetheclocktower

src/prototype/lang/array.js

@@ -720,22 +720,11 @@ Array.from = $A;
     var every = wrapNative(Array.prototype.every);
   }
 
-  // Prototype's `Array#inject` behaves similarly to ES5's `Array#reduce`.
-  var _reduce = arrayProto.reduce;
-  function inject(memo, iterator) {
-    iterator = iterator || Prototype.K;
-    var context = arguments[2];
-    // The iterator must be bound, as `Array#reduce` always binds to
-    // `undefined`.
-    return _reduce.call(this, iterator.bind(context), memo);
-  }
+  // We used to define an `inject` method here that relied on ES5's
+  // `Array#reduce` (if present), but using `reduce` prevents us from
+  // catching a thrown `$break`. So arrays now use the standard
+  // `Enumerable.inject` like they did previously.
 
-  // Piggyback on `Array#reduce` if it exists; otherwise fall back to the
-  // standard `Enumerable.inject`.
-  if (!arrayProto.reduce) {
-    var inject = Enumerable.inject;
-  }
-
   Object.extend(arrayProto, Enumerable);
 
   if (!arrayProto._reverse)
@@ -753,7 +742,6 @@ Array.from = $A;
     any:       some,
     every:     every,
     all:       every,
-    inject:    inject,
 
     clear:     clear,
     first:     first,

test/unit/enumerable_test.js

@@ -271,6 +271,13 @@ new Test.Unit.Runner({
       Fixtures.Primes.inject(0, function(sum, value) {
         return sum + value;
       }));
+      
+    var sum = Fixtures.Primes.inject(0, function(sum, value) {
+      if (value === 5) throw $break;
+      return sum + value;
+    });
+    
+    this.assertEqual(6, sum, 'inject should catch a thrown $break');
   },
 
   "test #inject passes memo, value, index and collection to the iterator": function() {