Adding another case that makes false/null to not cause match failure.

cake/libs/route/cake_route.php

@@ -280,7 +280,7 @@ class CakeRoute {
 				continue;
 			}
 			// keys that don't exist are different.
-			if (!$keyExists) {
+			if (!$keyExists && !empty($value)) {
 				$diff[$key] = $value;
 			}
 			

cake/tests/cases/libs/route/cake_route.test.php

@@ -289,6 +289,19 @@ class CakeRouteTestCase extends CakeTestCase {
 		$this->assertEqual($result, $expected);
 	}
 
+/**
+ * test that falsey values do not interrupt a match.
+ *
+ * @return void
+ */
+	function testMatchWithFalseyValues() {
+		$route = new CakeRoute('/:controller/:action/*', array('plugin' => null));
+		$result = $route->match(array(
+			'controller' => 'posts', 'action' => 'index', 'plugin' => null, 'admin' => false
+		));
+		$this->assertEqual($result, '/posts/index/');
+	}
+
 /**
  * test match() with greedy routes, named parameters and passed args.
  *