Adding _mergeVars to Shell. This allows $tasks and $uses to work much

like $uses in Controllers, and provides consistency in the framework.
Adding tests for merging vars.

cake/console/shells/shell.php

@@ -164,6 +164,36 @@ function __construct($stdout = null, $stderr = null, $stdin = null) {
 		if ($this->stdin == null) {
 			$this->stdin = new ConsoleInput('php://stdin');
 		}
+		$merge = array();
+		if ($this->tasks !== null && $this->tasks !== false) {
+			$merge[] = 'tasks';
+		}
+		if ($this->uses !== null && $this->uses !== false) {
+			$merge[] = 'uses';
+		}
+		if (!empty($merge)) {
+			$this->_mergeVars($merge, get_parent_class($this));
+		}
+	}
+
+/**
+ * Merges this objects $property with the property in $class' definition.
+ * This classes value for the property will be merged on top of $class'
+ *
+ * This provides some of the DRY magic CakePHP provides.  If you want to shut it off, redefine
+ * this method as an empty function.
+ *
+ * @param array $properties The name of the properties to merge.
+ * @param sting $class The class to merge the property with.
+ * @return void
+ */
+	protected function _mergeVars($properties, $class) {
+		$classProperties = get_class_vars($class);
+		foreach ($properties as $var) {
+			if (isset($classProperties[$var]) && !empty($classProperties[$var]) && is_array($this->{$var})) {
+				$this->{$var} = Set::merge($classProperties[$var], $this->{$var});
+			}
+		}
 	}
 
 /**

cake/tests/cases/console/shells/shell.test.php

@@ -69,6 +69,20 @@ public function _secret() {
 	protected function no_access() {
 
 	}
+
+	public function mergeVars($properties, $class) {
+		return $this->_mergeVars($properties, $class);
+	}
+}
+
+/**
+ * Class for testing merging vars
+ *
+ * @package cake.tests.cases.console
+ */
+class TestMergeShell extends Shell {
+	var $tasks = array('DbConfig', 'Fixture');
+	var $uses = array('Comment');
 }
 
 /**
@@ -134,6 +148,22 @@ public function testConstruct() {
 		$this->assertType('ConsoleOutput', $this->Shell->stderr);
 	}
 
+/**
+ * test merging vars
+ *
+ * @return void
+ */
+	function testMergeVars() {
+		$this->Shell->tasks = array('DbConfig' => array('one', 'two'));
+		$this->Shell->uses = array('Posts');
+		$this->Shell->mergeVars(array('tasks', 'uses'), 'TestMergeShell');
+
+		$this->assertEquals(array('DbConfig', 'Fixture', 'DbConfig' => array('one', 'two')), $this->Shell->tasks);
+		$expected = array('Fixture' => null, 'DbConfig' => array('one', 'two'));
+		$this->assertEquals($expected, Set::normalize($this->Shell->tasks), 'Normalized results are wrong.');
+		$this->assertEquals(array('Comment', 'Posts'), $this->Shell->uses, 'Merged models are wrong.');
+	}
+
 /**
  * testInitialize method
  *