Merge branch '3.1-stable' into develop

Conflicts resolved:
	.travis.yml
	system/core/CodeIgniter.php
	system/database/drivers/oci8/oci8_forge.php
	system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
	system/helpers/path_helper.php
	system/libraries/Email.php
	user_guide_src/source/changelog.rst
	user_guide_src/source/conf.py
	user_guide_src/source/contributing/index.rst
	user_guide_src/source/general/requirements.rst
	user_guide_src/source/general/styleguide.rst
	user_guide_src/source/installation/downloads.rst
	user_guide_src/source/installation/upgrade_310.rst
	user_guide_src/source/installation/upgrading.rst

10 files changed, 161 insertions, 132 deletions

diff --git a/system/libraries/Cache/drivers/Cache_memcached.php b/system/libraries/Cache/drivers/Cache_memcached.php
index ca3997ad5..ab8bfab8b 100644
--- a/system/libraries/Cache/drivers/Cache_memcached.php
+++ b/system/libraries/Cache/drivers/Cache_memcached.php
@@ -307,7 +307,7 @@ class CI_Cache_memcached extends CI_Driver {
 		{
 			$this->_memcached->close();
 		}
-		elseif ($this->_memcached instanceof Memcached)
+		elseif ($this->_memcached instanceof Memcached && method_exists($this->_memcached, 'quit'))
 		{
 			$this->_memcached->quit();
 		}
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index 0a55e1841..e9f69f065 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -387,18 +387,8 @@ class CI_Email {
 	public function __construct(array $config = array())
 	{
 		$this->charset = config_item('charset');
-
-		if (count($config) > 0)
-		{
-			$this->initialize($config);
-		}
-		else
-		{
-			$this->_smtp_auth = ! ($this->smtp_user === '' && $this->smtp_pass === '');
-		}
-
+		$this->initialize($config);
 		$this->_safe_mode = ( ! is_php('5.4') && ini_get('safe_mode'));
-		$this->charset = strtoupper($this->charset);
 
 		log_message('info', 'Email Class Initialized');
 	}
@@ -406,28 +396,15 @@ class CI_Email {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Destructor - Releases Resources
-	 *
-	 * @return	void
-	 */
-	public function __destruct()
-	{
-		if (is_resource($this->_smtp_connect))
-		{
-			$this->_send_command('quit');
-		}
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Initialize preferences
 	 *
-	 * @param	array
+	 * @param	array	$config
 	 * @return	CI_Email
 	 */
-	public function initialize($config = array())
+	public function initialize(array $config = array())
 	{
+		$this->clear();
+
 		foreach ($config as $key => $val)
 		{
 			if (isset($this->$key))
@@ -444,9 +421,9 @@ class CI_Email {
 				}
 			}
 		}
-		$this->clear();
 
-		$this->_smtp_auth = ! ($this->smtp_user === '' && $this->smtp_pass === '');
+		$this->charset = strtoupper($this->charset);
+		$this->_smtp_auth = isset($this->smtp_user[0], $this->smtp_pass[0]);
 
 		return $this;
 	}
@@ -1942,6 +1919,7 @@ class CI_Email {
 
 		if ( ! $this->_send_command('from', $this->clean_email($this->_headers['From'])))
 		{
+			$this->_smtp_end();
 			return FALSE;
 		}
 
@@ -1949,6 +1927,7 @@ class CI_Email {
 		{
 			if ( ! $this->_send_command('to', $val))
 			{
+				$this->_smtp_end();
 				return FALSE;
 			}
 		}
@@ -1959,6 +1938,7 @@ class CI_Email {
 			{
 				if ($val !== '' && ! $this->_send_command('to', $val))
 				{
+					$this->_smtp_end();
 					return FALSE;
 				}
 			}
@@ -1970,6 +1950,7 @@ class CI_Email {
 			{
 				if ($val !== '' && ! $this->_send_command('to', $val))
 				{
+					$this->_smtp_end();
 					return FALSE;
 				}
 			}
@@ -1977,6 +1958,7 @@ class CI_Email {
 
 		if ( ! $this->_send_command('data'))
 		{
+			$this->_smtp_end();
 			return FALSE;
 		}
 
@@ -1986,30 +1968,38 @@ class CI_Email {
 		$this->_send_data('.');
 
 		$reply = $this->_get_smtp_data();
-
 		$this->_set_error_message($reply);
 
+		$this->_smtp_end();
+
 		if (strpos($reply, '250') !== 0)
 		{
 			$this->_set_error_message('lang:email_smtp_error', $reply);
 			return FALSE;
 		}
 
-		if ($this->smtp_keepalive)
-		{
-			$this->_send_command('reset');
-		}
-		else
-		{
-			$this->_send_command('quit');
-		}
-
 		return TRUE;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
+	 * SMTP End
+	 *
+	 * Shortcut to send RSET or QUIT depending on keep-alive
+	 *
+	 * @return	void
+	 */
+	protected function _smtp_end()
+	{
+		($this->smtp_keepalive)
+			? $this->_send_command('reset')
+			: $this->_send_command('quit');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * SMTP Connect
 	 *
 	 * @return	string
@@ -2193,6 +2183,11 @@ class CI_Email {
 			return FALSE;
 		}
 
+		if ($this->smtp_keepalive)
+		{
+			$this->_smtp_auth = FALSE;
+		}
+
 		return TRUE;
 	}
 
@@ -2382,4 +2377,15 @@ class CI_Email {
 		return 'application/x-unknown-content-type';
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Destructor
+	 *
+	 * @return	void
+	 */
+	public function __destruct()
+	{
+		is_resource($this->_smtp_connect) && $this->_send_command('quit');
+	}
 }
diff --git a/system/libraries/Encryption.php b/system/libraries/Encryption.php
index 92c38a0ed..a10a5c20c 100644
--- a/system/libraries/Encryption.php
+++ b/system/libraries/Encryption.php
@@ -339,12 +339,26 @@ class CI_Encryption {
 	{
 		if (function_exists('random_bytes'))
 		{
-			return random_bytes((int) $length);
+			try
+			{
+				return random_bytes((int) $length);
+			}
+			catch (Exception $e)
+			{
+				log_message('error', $e->getMessage());
+				return FALSE;
+			}
+		}
+		elseif (defined('MCRYPT_DEV_URANDOM'))
+		{
+			return mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
 		}
 
-		return ($this->_driver === 'mcrypt')
-			? mcrypt_create_iv($length, MCRYPT_DEV_URANDOM)
-			: openssl_random_pseudo_bytes($length);
+		$is_secure = NULL;
+		$key = openssl_random_pseudo_bytes($length, $is_secure);
+		return ($is_secure === TRUE)
+			? $key
+			: FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -400,7 +414,7 @@ class CI_Encryption {
 		// The greater-than-1 comparison is mostly a work-around for a bug,
 		// where 1 is returned for ARCFour instead of 0.
 		$iv = (($iv_size = mcrypt_enc_get_iv_size($params['handle'])) > 1)
-			? mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM)
+			? $this->create_key($iv_size)
 			: NULL;
 
 		if (mcrypt_generic_init($params['handle'], $params['key'], $iv) < 0)
@@ -463,7 +477,7 @@ class CI_Encryption {
 		}
 
 		$iv = ($iv_size = openssl_cipher_iv_length($params['handle']))
-			? openssl_random_pseudo_bytes($iv_size)
+			? $this->create_key($iv_size)
 			: NULL;
 
 		$data = openssl_encrypt(
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index e4a518957..04445f5b7 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -494,6 +494,63 @@ class CI_Form_validation {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Prepare rules
+	 *
+	 * Re-orders the provided rules in order of importance, so that
+	 * they can easily be executed later without weird checks ...
+	 *
+	 * "Callbacks" are given the highest priority (always called),
+	 * followed by 'required' (called if callbacks didn't fail),
+	 * and then every next rule depends on the previous one passing.
+	 *
+	 * @param	array	$rules
+	 * @return	array
+	 */
+	protected function _prepare_rules($rules)
+	{
+		$new_rules = array();
+		$callbacks = array();
+
+		foreach ($rules as &$rule)
+		{
+			// Let 'required' always be the first (non-callback) rule
+			if ($rule === 'required')
+			{
+				array_unshift($new_rules, 'required');
+			}
+			// 'isset' is a kind of a weird alias for 'required' ...
+			elseif ($rule === 'isset' && (empty($new_rules) OR $new_rules[0] !== 'required'))
+			{
+				array_unshift($new_rules, 'isset');
+			}
+			// The old/classic 'callback_'-prefixed rules
+			elseif (is_string($rule) && strncmp('callback_', $rule, 9) === 0)
+			{
+				$callbacks[] = $rule;
+			}
+			// Proper callables
+			elseif (is_callable($rule))
+			{
+				$callbacks[] = $rule;
+			}
+			// "Named" callables; i.e. array('name' => $callable)
+			elseif (is_array($rule) && isset($rule[0], $rule[1]) && is_callable($rule[1]))
+			{
+				$callbacks[] = $rule;
+			}
+			// Everything else goes at the end of the queue
+			else
+			{
+				$new_rules[] = $rule;
+			}
+		}
+
+		return array_merge($callbacks, $new_rules);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Traverse a multidimensional $_POST array index until the data is found
 	 *
 	 * @param	array
@@ -580,70 +637,7 @@ class CI_Form_validation {
 			return;
 		}
 
-		// If the field is blank, but NOT required, no further tests are necessary
-		$callback = FALSE;
-		if ( ! in_array('required', $rules) && ($postdata === NULL OR $postdata === ''))
-		{
-			// Before we bail out, does the rule contain a callback?
-			foreach ($rules as &$rule)
-			{
-				if (is_string($rule))
-				{
-					if (strncmp($rule, 'callback_', 9) === 0)
-					{
-						$callback = TRUE;
-						$rules = array(1 => $rule);
-						break;
-					}
-				}
-				elseif (is_callable($rule))
-				{
-					$callback = TRUE;
-					$rules = array(1 => $rule);
-					break;
-				}
-				elseif (is_array($rule) && isset($rule[0], $rule[1]) && is_callable($rule[1]))
-				{
-					$callback = TRUE;
-					$rules = array(array($rule[0], $rule[1]));
-					break;
-				}
-			}
-
-			if ( ! $callback)
-			{
-				return;
-			}
-		}
-
-		// Isset Test. Typically this rule will only apply to checkboxes.
-		if (($postdata === NULL OR $postdata === '') && ! $callback)
-		{
-			if (in_array('isset', $rules, TRUE) OR in_array('required', $rules))
-			{
-				// Set the message type
-				$type = in_array('required', $rules) ? 'required' : 'isset';
-
-				$line = $this->_get_error_message($type, $row['field']);
-
-				// Build the error message
-				$message = $this->_build_error_msg($line, $this->_translate_fieldname($row['label']));
-
-				// Save the error message
-				$this->_field_data[$row['field']]['error'] = $message;
-
-				if ( ! isset($this->_error_array[$row['field']]))
-				{
-					$this->_error_array[$row['field']] = $message;
-				}
-			}
-
-			return;
-		}
-
-		// --------------------------------------------------------------------
-
-		// Cycle through each rule and run it
+		$rules = $this->_prepare_rules($rules);
 		foreach ($rules as $rule)
 		{
 			$_in_array = FALSE;
@@ -702,6 +696,17 @@ class CI_Form_validation {
 				$param = $match[2];
 			}
 
+			// Ignore empty, non-required inputs with a few exceptions ...
+			if (
+				($postdata === NULL OR $postdata === '')
+				&& $callback === FALSE
+				&& $callable === FALSE
+				&& ! in_array($rule, array('required', 'isset', 'matches'), TRUE)
+			)
+			{
+				continue;
+			}
+
 			// Call the function that corresponds to the rule
 			if ($callback OR $callable !== FALSE)
 			{
@@ -740,12 +745,6 @@ class CI_Form_validation {
 				{
 					$this->_field_data[$row['field']]['postdata'] = is_bool($result) ? $postdata : $result;
 				}
-
-				// If the field isn't required and we just processed a callback we'll move on...
-				if ( ! in_array('required', $rules, TRUE) && $result !== FALSE)
-				{
-					continue;
-				}
 			}
 			elseif ( ! method_exists($this, $rule))
 			{
@@ -1055,7 +1054,9 @@ class CI_Form_validation {
 	 */
 	public function required($str)
 	{
-		return is_array($str) ? (bool) count($str) : (trim($str) !== '');
+		return is_array($str)
+			? (empty($str) === FALSE)
+			: (trim($str) !== '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index f594b7125..24fe8c68d 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -456,7 +456,7 @@ class CI_Image_lib {
 			{
 				if (property_exists($this, $key))
 				{
-					if (in_array($key, array('wm_font_color', 'wm_shadow_color')))
+					if (in_array($key, array('wm_font_color', 'wm_shadow_color'), TRUE))
 					{
 						if (preg_match('/^#?([0-9a-f]{3}|[0-9a-f]{6})$/i', $val, $matches))
 						{
@@ -478,6 +478,10 @@ class CI_Image_lib {
 							continue;
 						}
 					}
+					elseif (in_array($key, array('width', 'height'), TRUE) && ! ctype_digit((string) $val))
+					{
+						continue;
+					}
 
 					$this->$key = $val;
 				}
@@ -862,27 +866,28 @@ class CI_Image_lib {
 
 		if ($action === 'crop')
 		{
-			$cmd .= ' -crop '.$this->width.'x'.$this->height.'+'.$this->x_axis.'+'.$this->y_axis.' "'.$this->full_src_path.'" "'.$this->full_dst_path .'" 2>&1';
+			$cmd .= ' -crop '.$this->width.'x'.$this->height.'+'.$this->x_axis.'+'.$this->y_axis;
 		}
 		elseif ($action === 'rotate')
 		{
-			$angle = ($this->rotation_angle === 'hor' OR $this->rotation_angle === 'vrt')
-					? '-flop' : '-rotate '.$this->rotation_angle;
-
-			$cmd .= ' '.$angle.' "'.$this->full_src_path.'" "'.$this->full_dst_path.'" 2>&1';
+			$cmd .= ($this->rotation_angle === 'hor' OR $this->rotation_angle === 'vrt')
+					? ' -flop'
+					: ' -rotate '.$this->rotation_angle;
 		}
 		else // Resize
 		{
 			if($this->maintain_ratio === TRUE)
 			{
-				$cmd .= ' -resize '.$this->width.'x'.$this->height.' "'.$this->full_src_path.'" "'.$this->full_dst_path.'" 2>&1';
+				$cmd .= ' -resize '.$this->width.'x'.$this->height;
 			}
 			else
 			{
-				$cmd .= ' -resize '.$this->width.'x'.$this->height.'\! "'.$this->full_src_path.'" "'.$this->full_dst_path.'" 2>&1';
+				$cmd .= ' -resize '.$this->width.'x'.$this->height.'\!';
 			}
 		}
 
+		$cmd .= ' "'.escapeshellarg($this->full_src_path).'" "'.escapeshellarg($this->full_dst_path).'" 2>&1';
+
 		$retval = 1;
 		// exec() might be disabled
 		if (function_usable('exec'))
diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
index dde84a775..3b391a8ef 100644
--- a/system/libraries/Session/Session.php
+++ b/system/libraries/Session/Session.php
@@ -91,6 +91,7 @@ class CI_Session {
 		// Note: BC workaround
 		elseif (config_item('sess_use_database'))
 		{
+			log_message('debug', 'Session: "sess_driver" is empty; using BC fallback to "sess_use_database".');
 			$this->_driver = 'database';
 		}
 
diff --git a/system/libraries/Session/drivers/Session_database_driver.php b/system/libraries/Session/drivers/Session_database_driver.php
index 317bd7d4d..cb152f91f 100644
--- a/system/libraries/Session/drivers/Session_database_driver.php
+++ b/system/libraries/Session/drivers/Session_database_driver.php
@@ -109,7 +109,10 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 		}
 
 		// Note: BC work-around for the old 'sess_table_name' setting, should be removed in the future.
-		isset($this->_config['save_path']) OR $this->_config['save_path'] = config_item('sess_table_name');
+		if ( ! isset($this->_config['save_path']) && ($this->_config['save_path'] = config_item('sess_table_name')))
+		{
+			log_message('debug', 'Session: "sess_save_path" is empty; using BC fallback to "sess_table_name".');
+		}
 	}
 
 	// ------------------------------------------------------------------------
diff --git a/system/libraries/Session/drivers/Session_files_driver.php b/system/libraries/Session/drivers/Session_files_driver.php
index 119bf6572..57c3777a2 100644
--- a/system/libraries/Session/drivers/Session_files_driver.php
+++ b/system/libraries/Session/drivers/Session_files_driver.php
@@ -95,6 +95,7 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 		}
 		else
 		{
+			log_message('debug', 'Session: "sess_save_path" is empty; using "session.save_path" value from php.ini.');
 			$this->_config['save_path'] = rtrim(ini_get('session.save_path'), '/\\');
 		}
 	}
diff --git a/system/libraries/Session/drivers/Session_redis_driver.php b/system/libraries/Session/drivers/Session_redis_driver.php
index d3a265958..592f1ff6c 100644
--- a/system/libraries/Session/drivers/Session_redis_driver.php
+++ b/system/libraries/Session/drivers/Session_redis_driver.php
@@ -279,7 +279,7 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 				if ($this->_redis->ping() === '+PONG')
 				{
 					$this->_release_lock();
-					if ($this->_redis->close() === $this->_failure)
+					if ($this->_redis->close() === FALSE)
 					{
 						return $this->_fail();
 					}
diff --git a/system/libraries/User_agent.php b/system/libraries/User_agent.php
index c4e11592d..60d159966 100644
--- a/system/libraries/User_agent.php
+++ b/system/libraries/User_agent.php
@@ -173,13 +173,11 @@ class CI_User_agent {
 	 */
 	public function __construct()
 	{
+		$this->_load_agent_file();
+
 		if (isset($_SERVER['HTTP_USER_AGENT']))
 		{
 			$this->agent = trim($_SERVER['HTTP_USER_AGENT']);
-		}
-
-		if ($this->agent !== NULL && $this->_load_agent_file())
-		{
 			$this->_compile_data();
 		}