Resolve #3408488 "Make unknownpathexcluder accept"

Closes #3408488

package_manager/src/PathExcluder/UnknownPathExcluder.php

@@ -88,34 +88,31 @@ final class UnknownPathExcluder implements EventSubscriberInterface {
     $this->composerInspector->validate($project_root);
 
     $vendor_dir = ltrim(str_replace($project_root, '', $this->pathLocator->getVendorDirectory()), '/');
-    $scaffold_files_paths = $this->getScaffoldFiles();
+    $include = [
+      $vendor_dir,
+      $web_root,
+      'composer.json',
+      'composer.lock',
+      ...$this->getScaffoldFiles(),
+    ];
 
     // Search for all files (including hidden ones) in the project root. We need
     // to use readdir() and friends here, rather than glob(), since certain
     // glob() flags aren't supported on all systems. We also can't use
     // \Drupal\Core\File\FileSystemInterface::scanDirectory(), because it
     // unconditionally ignores hidden files and directories.
-    $paths_in_project_root = [];
     $handle = opendir($project_root);
     if (empty($handle)) {
       throw new \RuntimeException("Could not scan for files in the project root.");
     }
-    while (($entry = readdir($handle)) !== FALSE) {
-      if ($entry === '.' || $entry === '..') {
+    while ($entry = readdir($handle)) {
+      if ($entry === '.' || $entry === '..' || in_array($entry, $include, TRUE)) {
         continue;
       }
-      $paths_in_project_root[] = $entry;
+      // We can add the path as-is; it's already relative to the project root.
+      $event->add($entry);
     }
     closedir($handle);
-
-    $paths = [];
-    $known_paths = array_merge([$vendor_dir, $web_root, "composer.json", "composer.lock"], $scaffold_files_paths);
-    foreach ($paths_in_project_root as $path_in_project_root) {
-      if (!in_array($path_in_project_root, $known_paths, TRUE)) {
-        $paths[] = $path_in_project_root;
-      }
-    }
-    $event->add(...$paths);
   }
 
   /**