Merge branch '6.4' into 7.1

* 6.4:
  Tweak error/exception handler registration

Author: nicolas-grekas

GenericRuntime.php

@@ -71,15 +71,15 @@ public function __construct(array $options = [])
         if ($debug) {
             umask(0000);
             $_SERVER[$debugKey] = $_ENV[$debugKey] = '1';
-
-            if (false !== $errorHandler = ($options['error_handler'] ?? BasicErrorHandler::class)) {
-                $errorHandler::register($debug);
-                $options['error_handler'] = false;
-            }
         } else {
             $_SERVER[$debugKey] = $_ENV[$debugKey] = '0';
         }
 
+        if (false !== $errorHandler = ($options['error_handler'] ?? BasicErrorHandler::class)) {
+            $errorHandler::register($debug);
+            $options['error_handler'] = false;
+        }
+
         $this->options = $options;
     }
 

Internal/BasicErrorHandler.php

@@ -30,10 +30,10 @@ public static function register(bool $debug): void
         }
 
         if (0 <= \ini_get('zend.assertions')) {
-            ini_set('zend.assertions', 1);
-            ini_set('assert.active', $debug);
-            ini_set('assert.exception', 1);
+            ini_set('zend.assertions', (int) $debug);
         }
+        ini_set('assert.active', 1);
+        ini_set('assert.exception', 1);
 
         set_error_handler(new self());
     }

Internal/SymfonyErrorHandler.php

@@ -24,12 +24,31 @@ class SymfonyErrorHandler
 {
     public static function register(bool $debug): void
     {
-        BasicErrorHandler::register($debug);
+        if (!class_exists(ErrorHandler::class)) {
+            BasicErrorHandler::register($debug);
 
-        if (class_exists(ErrorHandler::class)) {
+            return;
+        }
+
+        error_reporting(-1);
+
+        if (!\in_array(\PHP_SAPI, ['cli', 'phpdbg', 'embed'], true)) {
+            ini_set('display_errors', $debug);
+        } elseif (!filter_var(\ini_get('log_errors'), \FILTER_VALIDATE_BOOL) || \ini_get('error_log')) {
+            // CLI - display errors only if they're not already logged to STDERR
+            ini_set('display_errors', 1);
+        }
+
+        if (0 <= \ini_get('zend.assertions')) {
+            ini_set('zend.assertions', (int) $debug);
+        }
+        ini_set('assert.active', 1);
+        ini_set('assert.exception', 1);
+
+        if ($debug) {
             DebugClassLoader::enable();
-            restore_error_handler();
-            ErrorHandler::register(new ErrorHandler(new BufferingLogger(), $debug));
         }
+
+        ErrorHandler::register(new ErrorHandler(new BufferingLogger(), $debug));
     }
 }