Andy Blum · bb28be4a
--- a/core/themes/engines/twig/twig.engine
+++ b/core/themes/engines/twig/twig.engine
+      foreach ($suggestions as $key => &$suggestion) {
+        $hook = $hook ?? $variables['theme_hook_original'];
+        // Valid suggestions are $hook, $hook__*, and contain no hyphens.
+        if (($suggestion !== $hook && !str_starts_with($suggestion, $hook . '__')) || str_contains($suggestion, '-')) {
+          $invalid_suggestions[] = $suggestion;
+          unset($suggestions[$key]);
+          continue;
+        }
        $template = strtr($suggestion, '_', '-') . $extension;
        $prefix = ($template == $current_template) ? 'x' : '*';
        $suggestion = $prefix . ' ' . $template;
      }
      $output['debug_info'] .= "\n<!-- FILE NAME SUGGESTIONS:\n   " . Html::escape(implode("\n   ", $suggestions)) . "\n-->";
+
+      if (!empty($invalid_suggestions)) {
+        $output['debug_info'] .= "\n<!-- INVALID FILE NAME SUGGESTIONS:\n   " . Html::escape(implode("\n   ", $invalid_suggestions)) . "\n-->";