Index: src/test/php/LoggerMDCTest.php
===================================================================
--- src/test/php/LoggerMDCTest.php	(revision 0)
+++ src/test/php/LoggerMDCTest.php	(revision 0)
@@ -0,0 +1,146 @@
+<?php
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * @category   tests
+ * @package    log4php
+ * @license    http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
+ * @version    SVN: $Id$
+ * @link       http://logging.apache.org/log4php
+ */
+class LoggerMDCTest extends PHPUnit_Framework_TestCase {
+	
+	/** A pattern with 1 key. */
+	private $pattern1 = "%-5p %c: %X{key1} %m";
+	
+	/** A pattern with 2 keys. */
+	private $pattern2 = "%-5p %c: %X{key1} %X{key2} %m";
+	
+	/** A pattern with 3 keys (one is numeric). */
+	private $pattern3 = "%-5p %c: %X{key1} %X{key2} %X{3} %m";
+	
+	/** A pattern with a non-existant key. */
+	private $pattern4 = "%-5p %c: %X{key_does_not_exist} %m";
+	
+	/** A pattern with an empty key. */
+	private $pattern5 = "%-5p %c: %X{} %m";
+	
+	/** A pattern for testing values from $_ENV. */
+	private $patternEnv = "%-5p %c: %X{env.TEST} %m";
+	
+	/**
+	 * A pattern for testing values from $_SERVER. PHP_SELF chosen because it
+	 * appears on both Linux and Windows systems. 
+	 */
+	private $patternServer = "%-5p %c: %X{server.PHP_SELF} %m";
+	
+
+	public function testPatterns() {
+
+		// Create some data to test with
+		LoggerMDC::put('key1', 'valueofkey1');
+		LoggerMDC::put('key2', 'valueofkey2');
+		LoggerMDC::put(3, 'valueofkey3');
+		
+		$event = new LoggerLoggingEvent("LoggerLayoutPattern", new Logger("TEST"), LoggerLevel::getLevelInfo(), "Test message");
+
+		// Pattern with 1 key
+		$actual = $this->formatEvent($event, $this->pattern1);
+		$expected = "INFO  TEST: valueofkey1 Test message";
+		self::assertEquals($expected, $actual);
+		
+		// Pattern with 2 keys
+		$actual = $this->formatEvent($event, $this->pattern2);
+		$expected = "INFO  TEST: valueofkey1 valueofkey2 Test message";
+		self::assertEquals($expected, $actual);
+		
+		// Pattern with 3 keys (one numeric)
+		$actual = $this->formatEvent($event, $this->pattern3);
+		$expected = "INFO  TEST: valueofkey1 valueofkey2 valueofkey3 Test message";
+		self::assertEquals($expected, $actual);
+		
+		// Pattern with non-existant key
+		$actual = $this->formatEvent($event, $this->pattern4);
+		$expected = "INFO  TEST:  Test message";
+		self::assertEquals($expected, $actual);
+		
+		// Pattern with an empty key
+    	$actual = $this->formatEvent($event, $this->pattern5);
+		$expected = "INFO  TEST:  Test message";
+		self::assertEquals($expected, $actual);
+		
+		// Test key removal
+		LoggerMDC::remove('key1');
+		$value = LoggerMDC::get('key1');
+		self::assertEquals('', $value);
+		
+		// Pattern with 1 key, now removed
+		$actual = $this->formatEvent($event, $this->pattern1);
+		$expected = "INFO  TEST:  Test message";
+		self::assertEquals($expected, $actual);
+    }
+    
+    public function testEnvKey() {
+    	
+    	// Set an environment variable for testing
+    	if (putenv('TEST=abc') === false) {
+    		self::markTestSkipped("Unable to set environment variable for testing.");
+    	}
+    	
+    	// Test reading of the set variable
+    	self::assertEquals('abc', LoggerMDC::get('env.TEST'));
+    	
+    	// Test env variable in a pattern
+    	$event = new LoggerLoggingEvent("LoggerLayoutPattern", new Logger("TEST"), LoggerLevel::getLevelInfo(), "Test message");
+    	$actual = $this->formatEvent($event, $this->patternEnv);
+		$expected = "INFO  TEST: abc Test message";
+		self::assertEquals($expected, $actual);
+		
+		// Test reading a non-existant env variable
+		self::assertEquals('', LoggerMDC::get('env.hopefully_this_variable_doesnt_exist'));
+		
+		// Test reading an empty env variable
+		self::assertEquals('', LoggerMDC::get('env.'));
+    }
+    
+    public function testServerKey() {
+    	
+    	// Test reading a server variable
+    	$value = $_SERVER['PHP_SELF'];
+    	self::assertEquals($value, LoggerMDC::get('server.PHP_SELF'));
+    	
+		// Test the server variable in a pattern
+    	$event = new LoggerLoggingEvent("LoggerLayoutPattern", new Logger("TEST"), LoggerLevel::getLevelInfo(), "Test message");
+    	$actual = $this->formatEvent($event, $this->patternServer);
+		$expected = "INFO  TEST: $value Test message";
+		self::assertEquals($expected, $actual);
+		
+		// Test reading a non-existant server variable
+		self::assertEquals('', LoggerMDC::get('server.hopefully_this_variable_doesnt_exist'));
+		
+		// Test reading an empty server variable
+		self::assertEquals('', LoggerMDC::get('server.'));
+    }
+    
+	private function formatEvent($event, $pattern) {
+		$layout = new LoggerLayoutPattern();
+		$layout->setConversionPattern($pattern);
+		return $layout->format($event);
+	}
+}
+
+?>