Remove reverse merged properties.

CakePHP no longer needs this feature so it makes sense to remove it.

Cake/Test/TestCase/Utility/MergeVariablesTraitTest.php

@@ -121,15 +121,4 @@ public function testMergeVarsWithBoolean() {
 		$this->assertEquals(['test'], $object->hasBoolean);
 	}
 
-/**
- * Test that merging reversed works.
- *
- * @return void
- */
-	public function testMergeVariablesReversed() {
-		$object = new Grandchild();
-		$object->mergeVars(['listProperty'], ['reverse' => ['listProperty']]);
-		$expected = ['Four', 'Five', 'Two', 'Three', 'One'];
-		$this->assertSame($expected, $object->listProperty);
-	}
 }

Cake/Utility/MergeVariablesTrait.php

@@ -29,10 +29,6 @@ trait MergeVariablesTrait {
  *
  * - `associative` - A list of properties that should be treated as associative arrays.
  *   Properties in this list will be passed through Hash::normalize() before merging.
- * - `reverse` - A list of properties that should be merged in reverse.  Reverse merging
- *   allows the parent properties to follow the child classes.  Generally this option is only
- *   useful when merging list properties that need to maintain the child property values
- *   as the first elements in the merged list.
  *
  * @param array $properties An array of properties and the merge strategy for them.
  * @param array $options The options to use when merging properties.
@@ -71,19 +67,13 @@ protected function _mergeVars($properties, $options = []) {
  */
 	protected function _mergeProperty($property, $parentClasses, $options) {
 		$thisValue = $this->{$property};
-		$isAssoc = $isReversed = false;
+		$isAssoc =  false;
 		if (
 			isset($options['associative']) &&
 			in_array($property, (array)$options['associative'])
 		) {
 			$isAssoc = true;
 		}
-		if (
-			isset($options['reverse']) &&
-			in_array($property, (array)$options['reverse'])
-		) {
-			$isReversed = true;
-		}
 
 		if ($isAssoc) {
 			$thisValue = Hash::normalize($thisValue);
@@ -100,11 +90,7 @@ protected function _mergeProperty($property, $parentClasses, $options) {
 			if ($isAssoc) {
 				$parentProperty = Hash::normalize($parentProperty);
 			}
-			if ($isReversed) {
-				$thisValue = Hash::merge($thisValue, $parentProperty);
-			} else {
-				$thisValue = Hash::merge($parentProperty, $thisValue);
-			}
+			$thisValue = Hash::merge($parentProperty, $thisValue);
 		}
 		$this->{$property} = $thisValue;
 	}