Issue #3239295 by alexpott: Passing NULL to the $replace parameter of...

Issue #3239295 by alexpott: Passing NULL to the $replace parameter of str_replace() and preg_replace() triggers a deprecation in PHP 8.1

core/modules/field/src/Plugin/migrate/process/d7/FieldBundle.php

@@ -102,7 +102,7 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
     // For comment entity types get the destination bundle from the
     // d7_comment_type migration, if it exists.
     if ($entity_type === 'comment' && $bundle != 'comment_forum') {
-      $value = preg_replace('/comment_node_/', NULL, $bundle);
+      $value = str_replace('comment_node_', '', $bundle);
       $migration = 'd7_comment_type';
       $lookup_result = $this->migrateLookup->lookup($migration, [$value]);
       $lookup_result = empty($lookup_result) ? NULL : reset($lookup_result[0]);

core/modules/image/tests/src/Functional/ImageDimensionsTest.php

@@ -304,7 +304,7 @@ public function testImageDimensions() {
    * altered and the element is re-rendered each time.
    */
   protected function getImageTag($variables) {
-    return str_replace("\n", NULL, \Drupal::service('renderer')->renderRoot($variables));
+    return str_replace("\n", '', \Drupal::service('renderer')->renderRoot($variables));
   }
 
 }

core/modules/image/tests/src/Functional/ImageFieldDisplayTest.php

@@ -116,7 +116,7 @@ public function _testImageFieldFormatters($scheme) {
       '#height' => 20,
       '#alt' => $alt,
     ];
-    $default_output = str_replace("\n", NULL, $renderer->renderRoot($image));
+    $default_output = str_replace("\n", '', $renderer->renderRoot($image));
     $this->assertSession()->responseContains($default_output);
 
     // Test the image linked to file formatter.
@@ -305,7 +305,7 @@ public function testImageFieldSettings() {
     ];
     $this->drupalGet('node/' . $nid . '/edit');
     $this->submitForm($edit, 'Save');
-    $default_output = str_replace("\n", NULL, $renderer->renderRoot($image));
+    $default_output = str_replace("\n", '', $renderer->renderRoot($image));
     $this->assertSession()->responseContains($default_output);
 
     // Verify that alt/title longer than allowed results in a validation error.
@@ -398,7 +398,7 @@ public function testImageFieldDefaultImage() {
       '#width' => 40,
       '#height' => 20,
     ];
-    $default_output = str_replace("\n", NULL, $renderer->renderRoot($image));
+    $default_output = str_replace("\n", '', $renderer->renderRoot($image));
     $this->drupalGet('node/' . $node->id());
     $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Tags', $file->getCacheTags()[0]);
     // Verify that no image style cache tags are found.
@@ -423,7 +423,7 @@ public function testImageFieldDefaultImage() {
       '#height' => 20,
       '#alt' => $alt,
     ];
-    $image_output = str_replace("\n", NULL, $renderer->renderRoot($image));
+    $image_output = str_replace("\n", '', $renderer->renderRoot($image));
     $this->drupalGet('node/' . $nid);
     $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Tags', $file->getCacheTags()[0]);
     // Verify that no image style cache tags are found.
@@ -477,7 +477,7 @@ public function testImageFieldDefaultImage() {
       '#width' => 40,
       '#height' => 20,
     ];
-    $default_output = str_replace("\n", NULL, $renderer->renderRoot($image));
+    $default_output = str_replace("\n", '', $renderer->renderRoot($image));
     $this->drupalGet('node/' . $node->id());
     $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Tags', $file->getCacheTags()[0]);
     // Verify that no image style cache tags are found.

core/modules/responsive_image/tests/src/Functional/ResponsiveImageFieldDisplayTest.php

@@ -212,7 +212,7 @@ protected function doTestResponsiveImageFieldFormatters($scheme, $empty_styles =
       '#height' => 240,
       '#alt' => $alt,
     ];
-    $default_output = str_replace("\n", NULL, $renderer->renderRoot($image));
+    $default_output = str_replace("\n", '', $renderer->renderRoot($image));
     $this->assertSession()->responseContains($default_output);
 
     // Test field not being configured. This should not cause a fatal error.