diff --git a/.travis.yml b/.travis.yml
index 297d3e631..900901156 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ php:
   - 5.4
   - 5.5
   - 5.6
+  - 7.0
 
 env:
   - DB=mysql
diff --git a/lib/Cake/Cache/Cache.php b/lib/Cake/Cache/Cache.php
index 2cba7dadc..a7a01d0a1 100644
--- a/lib/Cake/Cache/Cache.php
+++ b/lib/Cake/Cache/Cache.php
@@ -275,10 +275,10 @@ class Cache {
  *
  * @param string $config [optional] The config name you wish to have garbage collected. Defaults to 'default'
  * @param int $expires [optional] An expires timestamp. Defaults to NULL
- * @return void
+ * @return bool
  */
 	public static function gc($config = 'default', $expires = null) {
-		static::$_engines[$config]->gc($expires);
+		return static::$_engines[$config]->gc($expires);
 	}
 
 /**
diff --git a/lib/Cake/Cache/Engine/FileEngine.php b/lib/Cake/Cache/Engine/FileEngine.php
index 80f0f2d6b..d650e60ee 100644
--- a/lib/Cake/Cache/Engine/FileEngine.php
+++ b/lib/Cake/Cache/Engine/FileEngine.php
@@ -109,7 +109,7 @@ class FileEngine extends CacheEngine {
  * @return bool True if the data was successfully cached, false on failure
  */
 	public function write($key, $data, $duration) {
-		if ($data === '' || !$this->_init) {
+		if (!$this->_init) {
 			return false;
 		}
 
diff --git a/lib/Cake/Console/ConsoleErrorHandler.php b/lib/Cake/Console/ConsoleErrorHandler.php
index a488b10f9..7cbb2df15 100644
--- a/lib/Cake/Console/ConsoleErrorHandler.php
+++ b/lib/Cake/Console/ConsoleErrorHandler.php
@@ -49,10 +49,10 @@ class ConsoleErrorHandler {
 /**
  * Handle an exception in the console environment. Prints a message to stderr.
  *
- * @param Exception $exception The exception to handle
+ * @param Exception|ParserError $exception The exception to handle
  * @return void
  */
-	public function handleException(Exception $exception) {
+	public function handleException($exception) {
 		$stderr = static::getStderr();
 		$stderr->write(__d('cake_console', "<error>Error:</error> %s\n%s",
 			$exception->getMessage(),
diff --git a/lib/Cake/Error/ErrorHandler.php b/lib/Cake/Error/ErrorHandler.php
index 3192ed5f8..9da40a660 100644
--- a/lib/Cake/Error/ErrorHandler.php
+++ b/lib/Cake/Error/ErrorHandler.php
@@ -109,11 +109,11 @@ class ErrorHandler {
  * This will either use custom exception renderer class if configured,
  * or use the default ExceptionRenderer.
  *
- * @param Exception $exception The exception to render.
+ * @param Exception|ParseError $exception The exception to render.
  * @return void
  * @see http://php.net/manual/en/function.set-exception-handler.php
  */
-	public static function handleException(Exception $exception) {
+	public static function handleException($exception) {
 		$config = Configure::read('Exception');
 		static::_log($exception, $config);
 
@@ -169,11 +169,11 @@ class ErrorHandler {
 /**
  * Handles exception logging
  *
- * @param Exception $exception The exception to render.
+ * @param Exception|ParseError $exception The exception to render.
  * @param array $config An array of configuration for logging.
  * @return bool
  */
-	protected static function _log(Exception $exception, $config) {
+	protected static function _log($exception, $config) {
 		if (empty($config['log'])) {
 			return false;
 		}
diff --git a/lib/Cake/Error/ExceptionRenderer.php b/lib/Cake/Error/ExceptionRenderer.php
index 04190eba5..a245b64ee 100644
--- a/lib/Cake/Error/ExceptionRenderer.php
+++ b/lib/Cake/Error/ExceptionRenderer.php
@@ -86,9 +86,9 @@ class ExceptionRenderer {
  * If the error is a CakeException it will be converted to either a 400 or a 500
  * code error depending on the code used to construct the error.
  *
- * @param Exception $exception Exception
+ * @param Exception|ParseError $exception Exception
  */
-	public function __construct(Exception $exception) {
+	public function __construct($exception) {
 		$this->controller = $this->_getController($exception);
 
 		if (method_exists($this->controller, 'appError')) {
diff --git a/lib/Cake/Model/Datasource/CakeSession.php b/lib/Cake/Model/Datasource/CakeSession.php
index b3b471686..147cc102b 100644
--- a/lib/Cake/Model/Datasource/CakeSession.php
+++ b/lib/Cake/Model/Datasource/CakeSession.php
@@ -143,7 +143,7 @@ class CakeSession {
 	public static function init($base = null) {
 		static::$time = time();
 
-		if (env('HTTP_USER_AGENT')) {
+		if (env('HTTP_USER_AGENT') && !static::$_userAgent) {
 			static::$_userAgent = md5(env('HTTP_USER_AGENT') . Configure::read('Security.salt'));
 		}
 
@@ -202,7 +202,6 @@ class CakeSession {
 
 		$id = static::id();
 		static::_startSession();
-
 		if (!$id && static::started()) {
 			static::_checkValid();
 		}
@@ -218,6 +217,9 @@ class CakeSession {
  * @return bool True if session has been started.
  */
 	public static function started() {
+		if (function_exists('session_status')) {
+			return isset($_SESSION) && (session_status() === PHP_SESSION_ACTIVE);
+		}
 		return isset($_SESSION) && session_id();
 	}
 
@@ -461,7 +463,12 @@ class CakeSession {
 		}
 
 		if (static::started()) {
+			if (session_id() && static::_hasSession()) {
+				session_write_close();
+				session_start();
+			}
 			session_destroy();
+			unset($_COOKIE[static::_cookieName()]);
 		}
 
 		$_SESSION = null;
@@ -584,7 +591,7 @@ class CakeSession {
  * @return bool
  */
 	protected static function _hasSession() {
-		return static::started() || isset($_COOKIE[static::_cookieName()]);
+		return static::started() || isset($_COOKIE[session_name()]) || (PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg');
 	}
 
 /**
@@ -753,7 +760,11 @@ class CakeSession {
 		if (isset($_COOKIE[session_name()])) {
 			setcookie(Configure::read('Session.cookie'), '', time() - 42000, static::$path);
 		}
-		session_regenerate_id(true);
+		if (!headers_sent()) {
+			session_write_close();
+			session_start();
+			session_regenerate_id(true);
+		}
 	}
 
 /**
diff --git a/lib/Cake/Model/Datasource/Session/CacheSession.php b/lib/Cake/Model/Datasource/Session/CacheSession.php
index 793701992..35f40d56e 100644
--- a/lib/Cake/Model/Datasource/Session/CacheSession.php
+++ b/lib/Cake/Model/Datasource/Session/CacheSession.php
@@ -52,7 +52,12 @@ class CacheSession implements CakeSessionHandlerInterface {
  * @return mixed The value of the key or false if it does not exist
  */
 	public function read($id) {
-		return Cache::read($id, Configure::read('Session.handler.config'));
+		$data = Cache::read($id, Configure::read('Session.handler.config'));
+
+		if (!is_numeric($data) && empty($data)) {
+			return '';
+		}
+		return $data;
 	}
 
 /**
@@ -63,7 +68,7 @@ class CacheSession implements CakeSessionHandlerInterface {
  * @return bool True for successful write, false otherwise.
  */
 	public function write($id, $data) {
-		return Cache::write($id, $data, Configure::read('Session.handler.config'));
+		return (bool)Cache::write($id, $data, Configure::read('Session.handler.config'));
 	}
 
 /**
@@ -73,7 +78,7 @@ class CacheSession implements CakeSessionHandlerInterface {
  * @return bool True for successful delete, false otherwise.
  */
 	public function destroy($id) {
-		return Cache::delete($id, Configure::read('Session.handler.config'));
+		return (bool)Cache::delete($id, Configure::read('Session.handler.config'));
 	}
 
 /**
@@ -83,7 +88,7 @@ class CacheSession implements CakeSessionHandlerInterface {
  * @return bool Success
  */
 	public function gc($expires = null) {
-		return Cache::gc(Configure::read('Session.handler.config'), $expires);
+		return (bool)Cache::gc(Configure::read('Session.handler.config'), $expires);
 	}
 
 }
diff --git a/lib/Cake/Model/Datasource/Session/DatabaseSession.php b/lib/Cake/Model/Datasource/Session/DatabaseSession.php
index 81cd708e8..cd4b904a8 100644
--- a/lib/Cake/Model/Datasource/Session/DatabaseSession.php
+++ b/lib/Cake/Model/Datasource/Session/DatabaseSession.php
@@ -92,11 +92,15 @@ class DatabaseSession implements CakeSessionHandlerInterface {
 			'conditions' => array($this->_model->alias . '.' . $this->_model->primaryKey => $id)
 		));
 
-		if (empty($row[$this->_model->alias]['data'])) {
-			return false;
+		if (empty($row[$this->_model->alias])) {
+			return '';
 		}
 
-		return $row[$this->_model->alias]['data'];
+		if (!is_numeric($row[$this->_model->alias]['data']) && empty($row[$this->_model->alias]['data'])) {
+			return '';
+		}
+
+		return (string)$row[$this->_model->alias]['data'];
 	}
 
 /**
@@ -123,9 +127,9 @@ class DatabaseSession implements CakeSessionHandlerInterface {
 			'counterCache' => false
 		);
 		try {
-			return $this->_model->save($record, $options);
+			return (bool)$this->_model->save($record, $options);
 		} catch (PDOException $e) {
-			return $this->_model->save($record, $options);
+			return (bool)$this->_model->save($record, $options);
 		}
 	}
 
@@ -136,7 +140,7 @@ class DatabaseSession implements CakeSessionHandlerInterface {
  * @return bool True for successful delete, false otherwise.
  */
 	public function destroy($id) {
-		return $this->_model->delete($id);
+		return (bool)$this->_model->delete($id);
 	}
 
 /**
@@ -151,7 +155,8 @@ class DatabaseSession implements CakeSessionHandlerInterface {
 		} else {
 			$expires = time() - $expires;
 		}
-		return $this->_model->deleteAll(array($this->_model->alias . ".expires <" => $expires), false, false);
+		$this->_model->deleteAll(array($this->_model->alias . ".expires <" => $expires), false, false);
+		return true;
 	}
 
 }
diff --git a/lib/Cake/Test/Case/Controller/Component/Auth/ControllerAuthorizeTest.php b/lib/Cake/Test/Case/Controller/Component/Auth/ControllerAuthorizeTest.php
index 80bb5c258..3216cdc3a 100644
--- a/lib/Cake/Test/Case/Controller/Component/Auth/ControllerAuthorizeTest.php
+++ b/lib/Cake/Test/Case/Controller/Component/Auth/ControllerAuthorizeTest.php
@@ -48,10 +48,15 @@ class ControllerAuthorizeTest extends CakeTestCase {
  * testControllerTypeError
  *
  * @expectedException PHPUnit_Framework_Error
+ * @throws PHPUnit_Framework_Error
  * @return void
  */
 	public function testControllerTypeError() {
-		$this->auth->controller(new StdClass());
+		try {
+			$this->auth->controller(new StdClass());
+		} catch (Throwable $t) {
+			throw new PHPUnit_Framework_Error($t);
+		}
 	}
 
 /**
diff --git a/lib/Cake/Test/Case/Controller/Component/SessionComponentTest.php b/lib/Cake/Test/Case/Controller/Component/SessionComponentTest.php
index fa7bae08b..294d46670 100644
--- a/lib/Cake/Test/Case/Controller/Component/SessionComponentTest.php
+++ b/lib/Cake/Test/Case/Controller/Component/SessionComponentTest.php
@@ -202,7 +202,6 @@ class SessionComponentTest extends CakeTestCase {
 		$this->assertEquals($Session->read('Test'), $array);
 		$Session->delete('Test');
 
-		$this->assertTrue($Session->write(array('Test'), 'some value'));
 		$this->assertTrue($Session->write(array('Test' => 'some value')));
 		$this->assertEquals('some value', $Session->read('Test'));
 		$Session->delete('Test');
diff --git a/lib/Cake/Test/Case/Core/ConfigureTest.php b/lib/Cake/Test/Case/Core/ConfigureTest.php
index 744932dac..6a1b4bbbd 100644
--- a/lib/Cake/Test/Case/Core/ConfigureTest.php
+++ b/lib/Cake/Test/Case/Core/ConfigureTest.php
@@ -450,11 +450,17 @@ class ConfigureTest extends CakeTestCase {
  * test reader() throwing exceptions on missing interface.
  *
  * @expectedException PHPUnit_Framework_Error
+ * @throws PHPUnit_Framework_Error
  * @return void
  */
 	public function testReaderExceptionOnIncorrectClass() {
 		$reader = new StdClass();
-		Configure::config('test', $reader);
+
+		try {
+			Configure::config('test', $reader);
+		} catch (Throwable $t) {
+			throw new PHPUnit_Framework_Error($t);
+		}
 	}
 
 /**
diff --git a/lib/Cake/Test/Case/Model/Datasource/Database/MysqlTest.php b/lib/Cake/Test/Case/Model/Datasource/Database/MysqlTest.php
index 6ad52f539..aa1353ecf 100644
--- a/lib/Cake/Test/Case/Model/Datasource/Database/MysqlTest.php
+++ b/lib/Cake/Test/Case/Model/Datasource/Database/MysqlTest.php
@@ -2909,10 +2909,15 @@ SQL;
  * testDropSchemaNoSchema method
  *
  * @expectedException PHPUnit_Framework_Error
+ * @throws PHPUnit_Framework_Error
  * @return void
  */
 	public function testDropSchemaNoSchema() {
-		$this->Dbo->dropSchema(null);
+		try {
+			$this->Dbo->dropSchema(null);
+		} catch (Throwable $t) {
+			throw new PHPUnit_Framework_Error($t);
+		}
 	}
 
 /**
diff --git a/lib/Cake/Test/Case/Model/Datasource/Session/CacheSessionTest.php b/lib/Cake/Test/Case/Model/Datasource/Session/CacheSessionTest.php
index 553f70bf4..387c05fc1 100644
--- a/lib/Cake/Test/Case/Model/Datasource/Session/CacheSessionTest.php
+++ b/lib/Cake/Test/Case/Model/Datasource/Session/CacheSessionTest.php
@@ -104,6 +104,8 @@ class CacheSessionTest extends CakeTestCase {
 	public function testRead() {
 		$this->storage->write('test_one', 'Some other value');
 		$this->assertEquals('Some other value', $this->storage->read('test_one'), 'Incorrect value.');
+		$this->storage->write('test_two', 0);
+		$this->assertEquals(0, $this->storage->read('test_two'));
 	}
 
 /**
diff --git a/lib/Cake/Test/Case/Model/Datasource/Session/DatabaseSessionTest.php b/lib/Cake/Test/Case/Model/Datasource/Session/DatabaseSessionTest.php
index da19cfcc6..fb5b0bfef 100644
--- a/lib/Cake/Test/Case/Model/Datasource/Session/DatabaseSessionTest.php
+++ b/lib/Cake/Test/Case/Model/Datasource/Session/DatabaseSessionTest.php
@@ -122,19 +122,8 @@ class DatabaseSessionTest extends CakeTestCase {
  * @return void
  */
 	public function testWrite() {
-		$result = $this->storage->write('foo', 'Some value');
-		$expected = array(
-			'Session' => array(
-				'id' => 'foo',
-				'data' => 'Some value',
-			)
-		);
-		$expires = $result['Session']['expires'];
-		unset($result['Session']['expires']);
-		$this->assertEquals($expected, $result);
-
-		$expected = time() + (Configure::read('Session.timeout') * 60);
-		$this->assertWithinMargin($expires, $expected, 1);
+		$this->storage->write('foo', 'Some value');
+		$this->assertEquals($this->storage->read('foo'), 'Some value');
 	}
 
 /**
@@ -154,13 +143,10 @@ class DatabaseSessionTest extends CakeTestCase {
  */
 	public function testRead() {
 		$this->storage->write('foo', 'Some value');
-
-		$result = $this->storage->read('foo');
-		$expected = 'Some value';
-		$this->assertEquals($expected, $result);
-
-		$result = $this->storage->read('made up value');
-		$this->assertFalse($result);
+		$this->assertEquals($this->storage->read('foo'), 'Some value');
+		$this->storage->write('bar', 0);
+		$this->assertEquals(0, $this->storage->read('bar'));
+		$this->assertSame('', $this->storage->read('made up value'));
 	}
 
 /**
@@ -172,7 +158,7 @@ class DatabaseSessionTest extends CakeTestCase {
 		$this->storage->write('foo', 'Some value');
 
 		$this->assertTrue($this->storage->destroy('foo'), 'Destroy failed');
-		$this->assertFalse($this->storage->read('foo'), 'Value still present.');
+		$this->assertSame($this->storage->read('foo'), '');
 	}
 
 /**
@@ -189,7 +175,7 @@ class DatabaseSessionTest extends CakeTestCase {
 
 		sleep(1);
 		$storage->gc();
-		$this->assertFalse($storage->read('foo'));
+		$this->assertSame($storage->read('foo'), '');
 	}
 
 /**
diff --git a/lib/Cake/Test/Case/Model/ModelValidationTest.php b/lib/Cake/Test/Case/Model/ModelValidationTest.php
index bd65b16e9..1636f7a21 100644
--- a/lib/Cake/Test/Case/Model/ModelValidationTest.php
+++ b/lib/Cake/Test/Case/Model/ModelValidationTest.php
@@ -2224,10 +2224,15 @@ class ModelValidationTest extends BaseModelTest {
  * Test that type hint exception is thrown
  *
  * @expectedException PHPUnit_Framework_Error
+ * @throws PHPUnit_Framework_Error
  * @return void
  */
 	public function testValidatorTypehintException() {
-		new ModelValidator('asdasds');
+		try {
+			new ModelValidator('asdasds');
+		} catch (Throwable $t) {
+			throw new PHPUnit_Framework_Error($t);
+		}
 	}
 
 /**
diff --git a/lib/Cake/Test/Case/View/JsonViewTest.php b/lib/Cake/Test/Case/View/JsonViewTest.php
index aa5027ae1..d90596f47 100644
--- a/lib/Cake/Test/Case/View/JsonViewTest.php
+++ b/lib/Cake/Test/Case/View/JsonViewTest.php
@@ -362,7 +362,9 @@ class JsonViewTest extends CakeTestCase {
 		$Controller = new Controller($Request, $Response);
 
 		// non utf-8 stuff
-		$data = array('data' => array('foo' => 'bar' . chr('0x97')));
+		$bar = 'bar';
+		$bar .= chr(0x97);
+		$data = array('data' => array('foo' => $bar));
 
 		$Controller->set($data);
 		$Controller->set('_serialize', 'data');
diff --git a/lib/Cake/Test/test_app/Model/Datasource/Session/TestAppLibSession.php b/lib/Cake/Test/test_app/Model/Datasource/Session/TestAppLibSession.php
index 2ba874dba..d4ac56fd8 100644
--- a/lib/Cake/Test/test_app/Model/Datasource/Session/TestAppLibSession.php
+++ b/lib/Cake/Test/test_app/Model/Datasource/Session/TestAppLibSession.php
@@ -12,18 +12,23 @@ class TestAppLibSession implements CakeSessionHandlerInterface {
 	}
 
 	public function close() {
+		return true;
 	}
 
 	public function read($id) {
+		return '';
 	}
 
 	public function write($id, $data) {
+		return true;
 	}
 
 	public function destroy($id) {
+		return true;
 	}
 
 	public function gc($expires = null) {
+		return true;
 	}
 
 }
diff --git a/lib/Cake/Test/test_app/Plugin/TestPlugin/Model/Datasource/Session/TestPluginSession.php b/lib/Cake/Test/test_app/Plugin/TestPlugin/Model/Datasource/Session/TestPluginSession.php
index acad188e0..b297fb47f 100644
--- a/lib/Cake/Test/test_app/Plugin/TestPlugin/Model/Datasource/Session/TestPluginSession.php
+++ b/lib/Cake/Test/test_app/Plugin/TestPlugin/Model/Datasource/Session/TestPluginSession.php
@@ -12,18 +12,23 @@ class TestPluginSession implements CakeSessionHandlerInterface {
 	}
 
 	public function close() {
+		return true;
 	}
 
 	public function read($id) {
+		return '';
 	}
 
 	public function write($id, $data) {
+		return true;
 	}
 
 	public function destroy($id) {
+		return true;
 	}
 
 	public function gc($expires = null) {
+		return true;
 	}
 
 }
diff --git a/lib/Cake/Utility/Security.php b/lib/Cake/Utility/Security.php
index 6ad3c01c1..511cf5efc 100644
--- a/lib/Cake/Utility/Security.php
+++ b/lib/Cake/Utility/Security.php
@@ -187,7 +187,7 @@ class Security {
 			return '';
 		}
 
-		srand(Configure::read('Security.cipherSeed'));
+		srand((int)Configure::read('Security.cipherSeed'));
 		$out = '';
 		$keyLength = strlen($key);
 		for ($i = 0, $textLength = strlen($text); $i < $textLength; $i++) {