Replace is_null with "=== null" comparison

modules/backend/classes/Controller.php

@@ -361,7 +361,7 @@ class Controller extends Extendable
         }
 
         // Load the view
-        if (!$this->suppressView && is_null($result)) {
+        if (!$this->suppressView && $result === null) {
             return $this->makeView($actionName);
         }
 

modules/backend/classes/ControllerBehavior.php

@@ -81,7 +81,7 @@ class ControllerBehavior extends ExtensionBase
         /*
          * Return all config
          */
-        if (is_null($name)) {
+        if ($name === null) {
             return $this->config;
         }
 

modules/backend/classes/FormField.php

@@ -266,7 +266,7 @@ class FormField
      */
     protected function evalConfig($config)
     {
-        if (is_null($config)) {
+        if ($config === null) {
             $config = [];
         }
 

modules/backend/classes/NavigationManager.php

@@ -317,7 +317,7 @@ class NavigationManager
     {
         $activeItem = null;
 
-        if (!is_null($owner) && !is_null($code)) {
+        if ($owner !== null && $code !== null) {
             $activeItem = @$this->items[$this->makeItemKey($owner, $code)];
         } else {
             foreach ($this->listMainMenuItems() as $item) {

modules/backend/controllers/Auth.php

@@ -75,7 +75,7 @@ class Auth extends Controller
             throw new ValidationException($validation);
         }
 
-        if (is_null($remember = config('cms.backendForceRemember', true))) {
+        if (($remember = config('cms.backendForceRemember', true)) === null) {
             $remember = (bool) post('remember');
         }
 

modules/backend/formwidgets/RecordFinder.php

@@ -213,7 +213,7 @@ class RecordFinder extends FormWidgetBase
     {
         list($model, $attribute) = $this->resolveModelAttribute($this->valueFrom);
 
-        if (!is_null($model)) {
+        if ($model !== null) {
             return $model->{$attribute};
         }
 

modules/backend/widgets/Filter.php

@@ -263,7 +263,7 @@ class Filter extends WidgetBase
             case 'text':
                 $values = post('options.value');
 
-                if (!is_null($values) && $values !== '') {
+                if ($values !== null && $values !== '') {
                     list($value) = $values;
                 }
                 else {

modules/backend/widgets/Form.php

@@ -672,7 +672,7 @@ class Form extends WidgetBase
         else {
 
             $fieldType = isset($config['type']) ? $config['type'] : null;
-            if (!is_string($fieldType) && !is_null($fieldType)) {
+            if (!is_string($fieldType) && $fieldType !== null) {
                 throw new ApplicationException(Lang::get(
                     'backend::lang.field.invalid_type',
                     ['type'=>gettype($fieldType)]

modules/cms/classes/Controller.php

@@ -484,7 +484,7 @@ class Controller
         $useCache = !Config::get('cms.twigNoCache');
         $isDebugMode = Config::get('app.debug', false);
         $strictVariables = Config::get('cms.enableTwigStrictVariables', false);
-        $strictVariables = is_null($strictVariables) ? $isDebugMode : $strictVariables;
+        $strictVariables = $strictVariables === null ? $isDebugMode : $strictVariables;
         $forceBytecode = Config::get('cms.forceBytecodeInvalidation', false);
 
         $options = [

modules/system/classes/MarkupManager.php

@@ -115,7 +115,7 @@ class MarkupManager
     {
         $items = $this->transactionMode ? 'transactionItems' : 'items';
 
-        if (is_null($this->$items)) {
+        if ($this->$items === null) {
             $this->$items = [];
         }
 

modules/system/console/OctoberEnv.php

@@ -266,7 +266,7 @@ class OctoberEnv extends Command
             return "'$value'";
         } elseif (is_bool($value)) {
             return $value ? 'true' : 'false';
-        } elseif (is_null($value)) {
+        } elseif ($value === null) {
             return 'null';
         }