Fix some minor PHP 8.1 deprecation warnings

6 files changed, 11 insertions, 12 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');
 	}
diff --git a/system/libraries/Encryption.php b/system/libraries/Encryption.php
index db6b30d46..933f6f232 100644
--- a/system/libraries/Encryption.php
+++ b/system/libraries/Encryption.php
@@ -476,7 +476,7 @@ class CI_Encryption {
 
 		$iv = ($iv_size = openssl_cipher_iv_length($params['handle']))
 			? $this->create_key($iv_size)
-			: NULL;
+			: '';
 
 		$data = openssl_encrypt(
 			$data,
@@ -585,7 +585,7 @@ class CI_Encryption {
 		}
 		else
 		{
-			$iv = NULL;
+			$iv = '';
 		}
 
 		if (mcrypt_generic_init($params['handle'], $params['key'], $iv) < 0)
@@ -632,7 +632,7 @@ class CI_Encryption {
 		}
 		else
 		{
-			$iv = NULL;
+			$iv = '';
 		}
 
 		return empty($params['handle'])
@@ -910,8 +910,8 @@ class CI_Encryption {
 	protected static function strlen($str)
 	{
 		return (self::$func_overload)
-			? mb_strlen($str, '8bit')
-			: strlen($str);
+			? mb_strlen((string) $str, '8bit')
+			: strlen((string) $str);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 9d976984e..1b7bbb96c 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1056,7 +1056,7 @@ class CI_Form_validation {
 	{
 		return is_array($str)
 			? (empty($str) === FALSE)
-			: (trim($str) !== '');
+			: (trim((string) $str) !== '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/libraries/User_agent.php b/system/libraries/User_agent.php
index a42975b35..c144db7a8 100644
--- a/system/libraries/User_agent.php
+++ b/system/libraries/User_agent.php
@@ -498,7 +498,7 @@ class CI_User_agent {
 			else
 			{
 				$referer_host = @parse_url($_SERVER['HTTP_REFERER'], PHP_URL_HOST);
-				$own_host = parse_url(config_item('base_url'), PHP_URL_HOST);
+				$own_host = parse_url((string) config_item('base_url'), PHP_URL_HOST);
 
 				$this->referer = ($referer_host && $referer_host !== $own_host);
 			}