Merge branch '3.1-stable' into develop

Conflicts resolved:
	system/database/drivers/sqlite/sqlite_driver.php
	system/database/drivers/sqlite/sqlite_forge.php
	system/database/drivers/sqlite/sqlite_result.php
	system/database/drivers/sqlite/sqlite_utility.php
	system/helpers/captcha_helper.php
	system/helpers/email_helper.php
	system/helpers/inflector_helper.php
	system/helpers/smiley_helper.php
	system/language/english/form_validation_lang.php
	system/libraries/Cart.php
	system/libraries/Form_validation.php
	system/libraries/Javascript.php
	system/libraries/Javascript/Jquery.php
	system/libraries/Session/SessionHandlerInterface.php
	tests/codeigniter/helpers/inflector_helper_test.php
	user_guide_src/source/helpers/inflector_helper.rst

16 files changed, 62 insertions, 56 deletions

diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index b6ab71784..b4f16b905 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -142,7 +142,7 @@ abstract class CI_DB_driver {
 	 *
 	 * @var	int
 	 */
-	public $port			= '';
+	public $port			= NULL;
 
 	/**
 	 * Persistent connection flag
@@ -1246,19 +1246,13 @@ abstract class CI_DB_driver {
 	 */
 	public function list_fields($table)
 	{
-		// Is there a cached result?
-		if (isset($this->data_cache['field_names'][$table]))
-		{
-			return $this->data_cache['field_names'][$table];
-		}
-
 		if (FALSE === ($sql = $this->_list_columns($table)))
 		{
 			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
 
 		$query = $this->query($sql);
-		$this->data_cache['field_names'][$table] = array();
+		$fields = array();
 
 		foreach ($query->result_array() as $row)
 		{
@@ -1280,10 +1274,10 @@ abstract class CI_DB_driver {
 				}
 			}
 
-			$this->data_cache['field_names'][$table][] = $row[$key];
+			$fields[] = $row[$key];
 		}
 
-		return $this->data_cache['field_names'][$table];
+		return $fields;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index dfc8a41b6..b086f7a81 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -348,7 +348,10 @@ abstract class CI_DB_forge {
 
 		if (($result = $this->db->query($sql)) !== FALSE)
 		{
-			isset($this->db->data_cache['table_names']) && $this->db->data_cache['table_names'][] = $table;
+			if (isset($this->db->data_cache['table_names']))
+			{
+				$this->db->data_cache['table_names'][] = $table;
+			}
 
 			// Most databases don't support creating indexes from within the CREATE TABLE statement
 			if ( ! empty($this->keys))
@@ -724,7 +727,7 @@ abstract class CI_DB_forge {
 				'type'			=> isset($attributes['TYPE']) ? $attributes['TYPE'] : NULL,
 				'length'		=> '',
 				'unsigned'		=> '',
-				'null'			=> '',
+				'null'			=> NULL,
 				'unique'		=> '',
 				'default'		=> '',
 				'auto_increment'	=> '',
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index f67b52507..4f0c28e78 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -167,26 +167,28 @@ class CI_DB_mysqli_driver extends CI_DB {
 			empty($this->encrypt['ssl_capath']) OR $ssl['capath'] = $this->encrypt['ssl_capath'];
 			empty($this->encrypt['ssl_cipher']) OR $ssl['cipher'] = $this->encrypt['ssl_cipher'];
 
-			if ( ! empty($ssl))
+			if (isset($this->encrypt['ssl_verify']))
 			{
-				if (isset($this->encrypt['ssl_verify']))
+				$client_flags |= MYSQLI_CLIENT_SSL;
+
+				if ($this->encrypt['ssl_verify'])
+				{
+					defined('MYSQLI_OPT_SSL_VERIFY_SERVER_CERT') && $this->_mysqli->options(MYSQLI_OPT_SSL_VERIFY_SERVER_CERT, TRUE);
+				}
+				// Apparently (when it exists), setting MYSQLI_OPT_SSL_VERIFY_SERVER_CERT
+				// to FALSE didn't do anything, so PHP 5.6.16 introduced yet another
+				// constant ...
+				//
+				// https://secure.php.net/ChangeLog-5.php#5.6.16
+				// https://bugs.php.net/bug.php?id=68344
+				elseif (defined('MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT'))
 				{
-					if ($this->encrypt['ssl_verify'])
-					{
-						defined('MYSQLI_OPT_SSL_VERIFY_SERVER_CERT') && $this->_mysqli->options(MYSQLI_OPT_SSL_VERIFY_SERVER_CERT, TRUE);
-					}
-					// Apparently (when it exists), setting MYSQLI_OPT_SSL_VERIFY_SERVER_CERT
-					// to FALSE didn't do anything, so PHP 5.6.16 introduced yet another
-					// constant ...
-					//
-					// https://secure.php.net/ChangeLog-5.php#5.6.16
-					// https://bugs.php.net/bug.php?id=68344
-					elseif (defined('MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT'))
-					{
-						$client_flags |= MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT;
-					}
+					$client_flags |= MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT;
 				}
+			}
 
+			if ( ! empty($ssl))
+			{
 				$client_flags |= MYSQLI_CLIENT_SSL;
 				$this->_mysqli->ssl_set(
 					isset($ssl['key'])    ? $ssl['key']    : NULL,
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
index 01ba15c1c..26bc30e14 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
@@ -167,6 +167,11 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 			empty($this->encrypt['ssl_capath']) OR $ssl[PDO::MYSQL_ATTR_SSL_CAPATH] = $this->encrypt['ssl_capath'];
 			empty($this->encrypt['ssl_cipher']) OR $ssl[PDO::MYSQL_ATTR_SSL_CIPHER] = $this->encrypt['ssl_cipher'];
 
+			if (defined('PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT') && isset($this->encrypt['ssl_verify']))
+			{
+				$ssl[PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT] = $this->encrypt['ssl_verify'];
+			}
+
 			// DO NOT use array_merge() here!
 			// It re-indexes numeric keys and the PDO_MYSQL_ATTR_SSL_* constants are integers.
 			empty($ssl) OR $this->options += $ssl;
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
index d7b751999..ff7a11075 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
@@ -136,7 +136,7 @@ class CI_DB_pdo_pgsql_forge extends CI_DB_pdo_forge {
 			if (isset($field[$i]['null']))
 			{
 				$sqls[] = $sql.' ALTER COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
-					.($field[$i]['null'] === TRUE ? ' DROP NOT NULL' : ' SET NOT NULL');
+					.(trim($field[$i]['null']) === $this->_null ? ' DROP NOT NULL' : ' SET NOT NULL');
 			}
 
 			if ( ! empty($field[$i]['new_name']))
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
index 396d10e61..f55d9a6c7 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
@@ -128,24 +128,18 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	 */
 	public function list_fields($table)
 	{
-		// Is there a cached result?
-		if (isset($this->data_cache['field_names'][$table]))
-		{
-			return $this->data_cache['field_names'][$table];
-		}
-
 		if (($result = $this->query('PRAGMA TABLE_INFO('.$this->protect_identifiers($table, TRUE, NULL, FALSE).')')) === FALSE)
 		{
 			return FALSE;
 		}
 
-		$this->data_cache['field_names'][$table] = array();
+		$fields = array();
 		foreach ($result->result_array() as $row)
 		{
-			$this->data_cache['field_names'][$table][] = $row['name'];
+			$fields[] = $row['name'];
 		}
 
-		return $this->data_cache['field_names'][$table];
+		return $fields;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/postgre/postgre_forge.php b/system/database/drivers/postgre/postgre_forge.php
index 418376ab4..353ddac99 100644
--- a/system/database/drivers/postgre/postgre_forge.php
+++ b/system/database/drivers/postgre/postgre_forge.php
@@ -131,7 +131,7 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 			if (isset($field[$i]['null']))
 			{
 				$sqls[] = $sql.' ALTER COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
-					.($field[$i]['null'] === TRUE ? ' DROP NOT NULL' : ' SET NOT NULL');
+					.(trim($field[$i]['null']) === $this->_null ? ' DROP NOT NULL' : ' SET NOT NULL');
 			}
 
 			if ( ! empty($field[$i]['new_name']))
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index 14d8349f4..5d057ba5a 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -230,24 +230,18 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 */
 	public function list_fields($table)
 	{
-		// Is there a cached result?
-		if (isset($this->data_cache['field_names'][$table]))
-		{
-			return $this->data_cache['field_names'][$table];
-		}
-
 		if (($result = $this->query('PRAGMA TABLE_INFO('.$this->protect_identifiers($table, TRUE, NULL, FALSE).')')) === FALSE)
 		{
 			return FALSE;
 		}
 
-		$this->data_cache['field_names'][$table] = array();
+		$fields = array();
 		foreach ($result->result_array() as $row)
 		{
-			$this->data_cache['field_names'][$table][] = $row['name'];
+			$fields[] = $row['name'];
 		}
 
-		return $this->data_cache['field_names'][$table];
+		return $fields;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/helpers/inflector_helper.php b/system/helpers/inflector_helper.php
index 04f2ac9d2..a36836b00 100644
--- a/system/helpers/inflector_helper.php
+++ b/system/helpers/inflector_helper.php
@@ -275,6 +275,17 @@ if ( ! function_exists('word_is_countable'))
 	}
 }
 
+// --------------------------------------------------------------------
+
+if ( ! function_exists('is_countable'))
+{
+	function is_countable($word)
+	{
+		trigger_error('is_countable() is a native PHP function since version 7.3.0; use word_is_countable() instead', E_USER_WARNING);
+		return word_is_countable($word);
+	}
+}
+
 // ------------------------------------------------------------------------
 
 if ( ! function_exists('ordinal_format'))
diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index e7215a066..74a2512c4 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -44,6 +44,7 @@ $lang['form_validation_valid_emails']		= 'The {field} field must contain all val
 $lang['form_validation_valid_url']		= 'The {field} field must contain a valid URL.';
 $lang['form_validation_valid_ip']		= 'The {field} field must contain a valid IP.';
 $lang['form_validation_valid_mac']		= 'The {field} field must contain a valid MAC.';
+$lang['form_validation_valid_base64']		= 'The {field} field must contain a valid Base64 string.';
 $lang['form_validation_min_length']		= 'The {field} field must be at least {param} characters in length.';
 $lang['form_validation_max_length']		= 'The {field} field cannot exceed {param} characters in length.';
 $lang['form_validation_exact_length']		= 'The {field} field must be exactly {param} characters in length.';
diff --git a/system/libraries/Session/Session_driver.php b/system/libraries/Session/Session_driver.php
index ed0f0cd82..14ebdb09f 100644
--- a/system/libraries/Session/Session_driver.php
+++ b/system/libraries/Session/Session_driver.php
@@ -115,13 +115,13 @@ abstract class CI_Session_driver implements SessionHandlerInterface {
 	/**
 	 * PHP 5.x validate ID
 	 *
-	 * Enforces session.use_strict_mode on PHP 5.x (7+ does it by itself)
+	 * Enforces session.use_strict_mode
 	 *
 	 * @return	void
 	 */
 	public function php5_validate_id()
 	{
-		if (PHP_VERSION_ID < 70000 && isset($_COOKIE[$this->_config['cookie_name']]) && ! $this->validateId($_COOKIE[$this->_config['cookie_name']]))
+		if (isset($_COOKIE[$this->_config['cookie_name']]) && ! $this->validateSessionId($_COOKIE[$this->_config['cookie_name']]))
 		{
 			unset($_COOKIE[$this->_config['cookie_name']]);
 		}
diff --git a/system/libraries/Session/drivers/Session_database_driver.php b/system/libraries/Session/drivers/Session_database_driver.php
index c626093f9..734fe624f 100644
--- a/system/libraries/Session/drivers/Session_database_driver.php
+++ b/system/libraries/Session/drivers/Session_database_driver.php
@@ -353,7 +353,7 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 	 * @param	string	$id
 	 * @return	bool
 	 */
-	public function validateId($id)
+	public function validateSessionId($id)
 	{
 		// Prevent previous QB calls from messing with our queries
 		$this->_db->reset_query();
diff --git a/system/libraries/Session/drivers/Session_files_driver.php b/system/libraries/Session/drivers/Session_files_driver.php
index a2d25cc8f..467059434 100644
--- a/system/libraries/Session/drivers/Session_files_driver.php
+++ b/system/libraries/Session/drivers/Session_files_driver.php
@@ -402,9 +402,11 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 	 * @param	string	$id
 	 * @return	bool
 	 */
-	public function validateId($id)
+	public function validateSessionId($id)
 	{
-		return is_file($this->_file_path.$id);
+		$result = is_file($this->_file_path.$id);
+		clearstatcache(TRUE, $this->_file_path.$id);
+		return $result;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php
index 7e026ad52..ab54f029f 100644
--- a/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -303,7 +303,7 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 	 * @param	string	$id
 	 * @return	bool
 	 */
-	public function validateId($id)
+	public function validateSessionId($id)
 	{
 		$this->_memcached->get($this->_key_prefix.$id);
 		return ($this->_memcached->getResultCode() === Memcached::RES_SUCCESS);
diff --git a/system/libraries/Session/drivers/Session_redis_driver.php b/system/libraries/Session/drivers/Session_redis_driver.php
index 6020a9ef9..07511e555 100644
--- a/system/libraries/Session/drivers/Session_redis_driver.php
+++ b/system/libraries/Session/drivers/Session_redis_driver.php
@@ -347,7 +347,7 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 	 * @param	string	$id
 	 * @return	bool
 	 */
-	public function validateId($id)
+	public function validateSessionId($id)
 	{
 		return (bool) $this->_redis->exists($this->_key_prefix.$id);
 	}
diff --git a/system/libraries/Xmlrpc.php b/system/libraries/Xmlrpc.php
index ffe0813f7..4e8c303c7 100644
--- a/system/libraries/Xmlrpc.php
+++ b/system/libraries/Xmlrpc.php
@@ -1211,7 +1211,7 @@ class XML_RPC_Message extends CI_Xmlrpc
 		{
 			echo '<pre>';
 
-			if (count($this->xh[$pname]['headers'] > 0))
+			if (count($this->xh[$pname]['headers']) > 0)
 			{
 				echo "---HEADERS---\n";
 				foreach ($this->xh[$pname]['headers'] as $header)