Don't mutate array during #remove. [closes #1079]

lodash.src.js

@@ -5310,17 +5310,32 @@
     function remove(array, predicate, thisArg) {
       var index = -1,
           length = array ? array.length : 0,
-          result = [];
+          result = [],
+          removes = 0,
+          indexes = [],
+          last;
 
       predicate = getCallback(predicate, thisArg, 3);
       while (++index < length) {
         var value = array[index];
         if (predicate(value, index, array)) {
+          if (last && last[0] + last[1] === index) {
+            ++last[1];
+          } else {
+            last = [index - removes, 1];
+            indexes.push(last);
+          }
           result.push(value);
-          splice.call(array, index--, 1);
+          ++removes;
-          length--;
         }
       }
+
+      index = -1;
+      length = indexes.length;
+      while (++index < length) {
+        last = indexes[index];
+        splice.call(array, last[0], last[1]);
+      }
       return result;
     }
 

test/test.js

@@ -12417,6 +12417,13 @@
       _.remove(array, function(num) { return num == null; });
       deepEqual(array, [1, 3]);
     });
+
+    test('should not mutate the array until all elements to remove are determined', 1, function() {
+      var array = [1, 2, 3];
+
+      _.remove(array, function(num, i) { return i % 2 == 0; });
+      deepEqual(array, [2]);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/