Issue #3075621 by greg.1.anderson: Scaffold plugin sometimes fails to write autoload.php

core/lib/Drupal/Component/Scaffold/GenerateAutoloadReferenceFile.php

@@ -62,11 +62,12 @@ public static function generateAutoload(IOInterface $io, $package_name, $web_roo
    */
   public static function autoloadFileCommitted(IOInterface $io, $package_name, $web_root) {
     $autoload_path = static::autoloadPath($package_name, $web_root);
-    $location = dirname($autoload_path->fullPath());
-    if (!file_exists($location)) {
+    $autoload_file = $autoload_path->fullPath();
+    $location = dirname($autoload_file);
+    if (!file_exists($autoload_file)) {
       return FALSE;
     }
-    return Git::checkTracked($io, $location, $location);
+    return Git::checkTracked($io, $autoload_file, $location);
   }
 
   /**

core/tests/Drupal/Tests/Component/Scaffold/Functional/ManageGitIgnoreTest.php

@@ -104,10 +104,12 @@ public function testManageGitIgnore() {
     // Note that the drupal-composer-drupal-project fixture does not
     // have any configuration settings related to .gitignore management.
     $sut = $this->createSutWithGit('drupal-composer-drupal-project');
+    $this->assertFileNotExists($sut . '/docroot/autoload.php');
     $this->assertFileNotExists($sut . '/docroot/index.php');
     $this->assertFileNotExists($sut . '/docroot/sites/.gitignore');
     // Run the scaffold command.
     $this->fixtures->runScaffold($sut);
+    $this->assertFileExists($sut . '/docroot/autoload.php');
     $this->assertFileExists($sut . '/docroot/index.php');
     $expected = <<<EOT
 build
@@ -147,9 +149,11 @@ public function testUnmanagedGitIgnoreWhenDisabled() {
     // Note that the drupal-drupal fixture has a configuration setting
     // `"gitignore": false,` which disables .gitignore file handling.
     $sut = $this->createSutWithGit('drupal-drupal');
+    $this->assertFileNotExists($sut . '/docroot/autoload.php');
     $this->assertFileNotExists($sut . '/docroot/index.php');
     // Run the scaffold command.
     $this->fixtures->runScaffold($sut);
+    $this->assertFileExists($sut . '/autoload.php');
     $this->assertFileExists($sut . '/index.php');
     $this->assertFileNotExists($sut . '/.gitignore');
     $this->assertFileNotExists($sut . '/docroot/sites/default/.gitignore');