Complete the proposed changes from PR bcit-ci#4300

Author: narfbg

system/database/DB_driver.php

@@ -381,6 +381,7 @@ public function __construct($params)
 	 * Initialize Database Settings
 	 *
 	 * @return	bool
+	 * @throws	RuntimeException	In case of failure
 	 */
 	public function initialize()
 	{
@@ -429,14 +430,7 @@ public function initialize()
 			// We still don't have a connection?
 			if ( ! $this->conn_id)
 			{
-				log_message('error', 'Unable to connect to the database');
-
-				if ($this->db_debug)
-				{
-					$this->display_error('db_unable_to_connect');
-				}
-
-				throw new RuntimeException('Database connection failure.');
+				throw new RuntimeException('Unable to connect to the database.');
 			}
 		}
 
@@ -751,14 +745,7 @@ public function query($sql, $binds = FALSE, $return_object = NULL)
 	 */
 	public function simple_query($sql)
 	{
-		if ( ! $this->conn_id)
-		{
-			if ( ! $this->initialize())
-			{
-				return FALSE;
-			}
-		}
-
+		empty($this->conn_id) && $this->initialize();
 		return $this->_execute($sql);
 	}
 

user_guide_src/source/changelog.rst

@@ -13,7 +13,7 @@ Release Date: Not Released
 
 -  Database
 
-   -  CI_DB_driver::initialize() throws a "Database connection failure." RuntimeException if couldn't connect to the database.
+   -  Failure to initialize a database connection will now throw a ``RuntimeException``.
 
 
 Version 3.0.4

user_guide_src/source/database/db_driver_reference.rst

@@ -19,6 +19,7 @@ This article is intended to be a reference for them.
 
 		:returns:	TRUE on success, FALSE on failure
 		:rtype:	bool
+		:throws:	RuntimeException	In case of failure
 
 		Initialize database settings, establish a connection to
 		the database.