Issue #3173888 by andypost, alexpott, Gábor Hojtsy: Error handler signature changed in PHP 8

core/includes/bootstrap.inc

@@ -299,13 +299,10 @@ function watchdog_exception($type, Exception $exception, $message = NULL, $varia
  *   (optional) The filename that the error was raised in.
  * @param $line
  *   (optional) The line number the error was raised at.
- * @param $context
- *   (optional) An array that points to the active symbol table at the point the
- *   error occurred.
  */
-function _drupal_error_handler($error_level, $message, $filename = NULL, $line = NULL, $context = NULL) {
+function _drupal_error_handler($error_level, $message, $filename = NULL, $line = NULL) {
   require_once __DIR__ . '/errors.inc';
-  _drupal_error_handler_real($error_level, $message, $filename, $line, $context);
+  _drupal_error_handler_real($error_level, $message, $filename, $line);
 }
 
 /**

core/includes/errors.inc

@@ -54,11 +54,8 @@ function drupal_error_levels() {
  *   The filename that the error was raised in.
  * @param $line
  *   The line number the error was raised at.
- * @param $context
- *   An array that points to the active symbol table at the point the error
- *   occurred.
  */
-function _drupal_error_handler_real($error_level, $message, $filename, $line, $context) {
+function _drupal_error_handler_real($error_level, $message, $filename, $line) {
   if ($error_level & error_reporting()) {
     $types = drupal_error_levels();
     list($severity_msg, $severity_level) = $types[$error_level];

core/tests/Drupal/KernelTests/Core/Database/QueryTest.php

@@ -67,14 +67,14 @@ class QueryTest extends DatabaseTestBase {
   public function testConditionOperatorArgumentsSQLInjection() {
     $injection = "IS NOT NULL) ;INSERT INTO {test} (name) VALUES ('test12345678'); -- ";
 
-    $previous_error_handler = set_error_handler(function ($severity, $message, $filename, $lineno, $context) use (&$previous_error_handler) {
+    $previous_error_handler = set_error_handler(function ($severity, $message, $filename, $lineno) use (&$previous_error_handler) {
       // Normalize the filename to use UNIX directory separators.
       if (preg_match('@core/lib/Drupal/Core/Database/Query/Condition.php$@', str_replace(DIRECTORY_SEPARATOR, '/', $filename))) {
         // Convert errors to exceptions for testing purposes below.
         throw new \ErrorException($message, 0, $severity, $filename, $lineno);
       }
       if ($previous_error_handler) {
-        return $previous_error_handler($severity, $message, $filename, $lineno, $context);
+        return $previous_error_handler($severity, $message, $filename, $lineno);
       }
     });
     try {

core/tests/Drupal/Tests/Core/Asset/LibraryDiscoveryTest.php

@@ -103,13 +103,13 @@ class LibraryDiscoveryTest extends UnitTestCase {
    * Tests getting a deprecated library.
    */
   public function testAssetLibraryDeprecation() {
-    $previous_error_handler = set_error_handler(function ($severity, $message, $file, $line, $context) use (&$previous_error_handler) {
+    $previous_error_handler = set_error_handler(function ($severity, $message, $file, $line) use (&$previous_error_handler) {
       // Convert deprecation error into a catchable exception.
       if ($severity === E_USER_DEPRECATED) {
         throw new \ErrorException($message, 0, $severity, $file, $line);
       }
       if ($previous_error_handler) {
-        return $previous_error_handler($severity, $message, $file, $line, $context);
+        return $previous_error_handler($severity, $message, $file, $line);
       }
     });