diff --git a/core/includes/file.inc b/core/includes/file.inc
index 551e983..cc1604e 100644
--- a/core/includes/file.inc
+++ b/core/includes/file.inc
@@ -2361,7 +2361,9 @@ function drupal_mkdir($uri, $mode = NULL, $recursive = FALSE, $context = NULL) {
     foreach (explode('/', $uri_flat) as $uri_element) {
       $uri_existing .= '/' . $uri_element;
       // Fail if permisions can not be changed.
-      $success = drupal_chmod($uri_existing, $mode);
+      if (!$success = drupal_chmod($uri_existing, $mode)) {
+        break;
+      }
     }
   }
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/File/DirectoryTest.php b/core/modules/system/lib/Drupal/system/Tests/File/DirectoryTest.php
index 497f2eb..3edc12a 100644
--- a/core/modules/system/lib/Drupal/system/Tests/File/DirectoryTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/File/DirectoryTest.php
@@ -24,7 +24,7 @@ class DirectoryTest extends FileTestBase {
    *
    * Checks valid and invalid URI variations, single and recursively.
    */
-  function testFileCheckDirectoryHandling() {
+  function testFileDirectoryHandling() {
     $directories = array();
 
     // Valid stream wrapper scheme.
@@ -47,21 +47,22 @@ class DirectoryTest extends FileTestBase {
 
     foreach ($directories as $directory) {
       // Check directory handling.
-      $this->checkFileCheckDirectoryHandling($directory . $this->randomName());
+      $this->checkFileDirectoryHandling($directory . $this->randomName());
       // Check recursively.
-      $this->checkFileCheckDirectoryHandling($directory . $this->randomName() . '/' . $this->randomName());
+      $this->checkFileDirectoryHandling($directory . $this->randomName() . '/' . $this->randomName());
     }
   }
 
   /**
-   * Helper method for testFileCheckDirectoryHandling().
+   * Checks directory handling functions.
    *
    * @param string $directory
    *   A file directory path to operate on.
+   *
+   * @see Drupal\system\Tests\File\DirectoryTest::testFileDirectoryHandling().
    */
   function checkFileDirectoryHandling($directory = NULL) {
     // Assert directory does not already exist.
-    // @todo check recursively?
     $this->assertFalse(is_dir($directory), t('Directory does not exist prior to testing.'));
 
     // Non-existent directory.