diff --git a/upload/source/class/discuz/discuz_application.php b/upload/source/class/discuz/discuz_application.php
index 1b1c4a78d8e715d42e06df55b46c708437dd8b1d..5f14a2a36ff3cda8c264766ff14bbb0649c98c4c 100644
--- a/upload/source/class/discuz/discuz_application.php
+++ b/upload/source/class/discuz/discuz_application.php
@@ -445,7 +445,7 @@ class discuz_application extends discuz_base{
 			$this->var['sid'] = $this->session->sid;
 			$this->var['session'] = $this->session->var;
 
-			if(!empty($this->var['sid']) && $this->var['sid'] != $this->var['cookie']['sid']) {
+			if(isset($this->var['sid']) && $this->var['sid'] !== $this->var['cookie']['sid']) {
 				dsetcookie('sid', $this->var['sid'], 86400);
 			}
 
diff --git a/upload/source/class/helper/helper_seccheck.php b/upload/source/class/helper/helper_seccheck.php
index 300ed1f360e4fc15f9ec615ae74c44f185ebd166..0acfd851a1425e83aca3ecd9de300563080193e3 100644
--- a/upload/source/class/helper/helper_seccheck.php
+++ b/upload/source/class/helper/helper_seccheck.php
@@ -28,7 +28,6 @@ class helper_seccheck {
 					$secappend = $_GET['secqaahash'];
 				}
 			}
-			$secappend = str_replace($_G['sid'], '', $secappend);
 		}
 		if(!isset($_G['cookie']['sec'.$type.$secappend])) {
 			return false;
@@ -63,7 +62,6 @@ class helper_seccheck {
 					$secappend = $_GET['secqaahash'];
 				}
 			}
-			$secappend = str_replace($_G['sid'], '', $secappend);
 		}
 		$ssid = C::t('common_seccheck')->insert(array(
 		    'dateline' => TIMESTAMP,
diff --git a/upload/source/function/function_core.php b/upload/source/function/function_core.php
index a2249cceeba5d4e4fa7a434aee1ab09fdc581fdf..649cd4e77999fc56ea3c8ad5eca38759a06383b6 100644
--- a/upload/source/function/function_core.php
+++ b/upload/source/function/function_core.php
@@ -267,7 +267,7 @@ function dsetcookie($var, $value = '', $life = 0, $prefix = 1, $httponly = false
 	$var = ($prefix ? $config['cookiepre'] : '').$var;
 	$_COOKIE[$var] = $value;
 
-	if($value == '' || $life < 0) {
+	if($value === '' || $life < 0) {
 		$value = '';
 		$life = -1;
 	}