Changes behaviour of _useLogger so that already-configured loggers are not overridden

lib/Cake/Console/Shell.php

@@ -964,15 +964,48 @@ class Shell extends Object {
 			CakeLog::drop('stderr');
 			return;
 		}
+		if (!$this->_loggerIsConfigured("stdout")) {
+			$this->_configureStdOutLogger();
+		}
+		if (!$this->_loggerIsConfigured("stderr")) {
+			$this->_configureStdErrLogger();
+		}
+	}
+
+/**
+ * Configure the stdout logger
+ * 
+ * @return void
+ */
+	protected function _configureStdOutLogger() {
 		CakeLog::config('stdout', array(
 			'engine' => 'Console',
 			'types' => array('notice', 'info'),
 			'stream' => $this->stdout,
 		));
+	}
+
+/**
+ * Configure the stderr logger
+ * 
+ * @return void
+ */
+	protected function _configureStdErrLogger() {
 		CakeLog::config('stderr', array(
 			'engine' => 'Console',
 			'types' => array('emergency', 'alert', 'critical', 'error', 'warning', 'debug'),
 			'stream' => $this->stderr,
 		));
 	}
+
+/**
+ * Checks if the given logger is configured
+ * 
+ * @param string $logger The name of the logger to check 
+ * @return bool
+ */
+	protected function _loggerIsConfigured($logger) {
+		$configured = CakeLog::configured();
+		return in_array($logger, $configured);
+	}
 }

lib/Cake/Test/Case/Console/ShellTest.php

@@ -920,6 +920,8 @@ TEXT;
  * @return void
  */
 	public function testFileAndConsoleLogging() {
+		CakeLog::disable('stdout');
+		CakeLog::disable('stderr');
 		// file logging
 		$this->Shell->log_something();
 		$this->assertTrue(file_exists(LOGS . 'error.log'));
@@ -944,6 +946,9 @@ TEXT;
 		$this->assertTrue(file_exists(LOGS . 'error.log'));
 		$contents = file_get_contents(LOGS . 'error.log');
 		$this->assertContains($this->Shell->testMessage, $contents);
+
+		CakeLog::enable('stdout');
+		CakeLog::enable('stderr');
 	}
 
 /**
@@ -995,4 +1000,26 @@ TEXT;
 	public function testGetInvalidHelper() {
 		$this->Shell->helper("tomato");
 	}
+
+	/**
+	 * @return void
+	 */
+	public function testShellLoggersDoNotGetOverridden()
+	{
+		$shell = $this->getMock("Shell", array(
+			"_loggerIsConfigured",
+			"configureStdOutLogger",
+			"configureStdErrLogger",
+		));
+		
+		$shell->expects($this->any())
+			->method("_loggerIsConfigured")
+			->will($this->returnValue(true));
+		
+		$shell->expects($this->never())
+			->method("_configureStdOutLogger");
+
+		$shell->expects($this->never())
+			->method("_configureStdErrLogger");	
+	}
 }