Fix some minor PHP 8.1 deprecation warnings

3 files changed, 4 insertions, 5 deletions

diff --git a/system/core/Common.php b/system/core/Common.php
index 9e23a4ea5..a9b8828e3 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -778,11 +778,9 @@ if ( ! function_exists('_stringify_attributes'))
 	 */
 	function _stringify_attributes($attributes, $js = FALSE)
 	{
-		$atts = NULL;
-
 		if (empty($attributes))
 		{
-			return $atts;
+			return NULL;
 		}
 
 		if (is_string($attributes))
@@ -792,6 +790,7 @@ if ( ! function_exists('_stringify_attributes'))
 
 		$attributes = (array) $attributes;
 
+		$atts = '';
 		foreach ($attributes as $key => $val)
 		{
 			$atts .= ($js) ? $key.'='.$val.',' : ' '.$key.'="'.$val.'"';
diff --git a/system/core/Input.php b/system/core/Input.php
index 3fb4121eb..c3a0a9094 100644
--- a/system/core/Input.php
+++ b/system/core/Input.php
@@ -565,7 +565,7 @@ class CI_Input {
 				$which = FILTER_FLAG_IPV6;
 				break;
 			default:
-				$which = NULL;
+				$which = 0;
 				break;
 		}
 
diff --git a/system/core/Security.php b/system/core/Security.php
index f6b0407f8..d1d4f8432 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -193,7 +193,7 @@ class CI_Security {
 			$this->_csrf_set_hash();
 		}
 
-		$this->charset = strtoupper(config_item('charset'));
+		$this->charset = strtoupper((string) config_item('charset'));
 
 		log_message('info', 'Security Class Initialized');
 	}