Fix a number of CI_Cache bugs

Fixes #4277
Supersedes #4474
Really fixes #4066

1 files changed, 6 insertions, 0 deletions

diff --git a/system/libraries/Cache/drivers/Cache_redis.php b/system/libraries/Cache/drivers/Cache_redis.php
index 81b49e2fc..e9194a499 100644
--- a/system/libraries/Cache/drivers/Cache_redis.php
+++ b/system/libraries/Cache/drivers/Cache_redis.php
@@ -91,6 +91,12 @@ class CI_Cache_redis extends CI_Driver
 	 */
 	public function __construct()
 	{
+		if ( ! $this->is_supported())
+		{
+			log_message('error', 'Cache: Failed to create Redis object; extension not loaded?');
+			return;
+		}
+
 		$config = array();
 		$CI =& get_instance();