Throw NoUserException when attempting to init mount point for null user

In some scenarios initMountPoints is called with an empty user, and
also there is no user in the session.

In such cases, it is unsafe to let the code move on with an empty user.

2 files changed, 25 insertions, 0 deletions

diff --git a/lib/private/files/filesystem.php b/lib/private/files/filesystem.php
index a9138b0d2d7..ec9b537a358 100644
--- a/lib/private/files/filesystem.php
+++ b/lib/private/files/filesystem.php
@@ -372,6 +372,9 @@ class Filesystem {
 		if ($user == '') {
 			$user = \OC_User::getUser();
 		}
+		if ($user === null || $user === false || $user === '') {
+			throw new \OC\User\NoUserException('Attempted to initialize mount points for null user and no user in session');
+		}
 		if (isset(self::$usersSetup[$user])) {
 			return;
 		}
diff --git a/tests/lib/files/filesystem.php b/tests/lib/files/filesystem.php
index db1f22f894a..8245af0ace1 100644
--- a/tests/lib/files/filesystem.php
+++ b/tests/lib/files/filesystem.php
@@ -320,6 +320,28 @@ class Filesystem extends \Test\TestCase {
 	}
 
 	/**
+	 * @expectedException \OC\User\NoUserException
+	 */
+	public function testNullUserThrows() {
+		\OC\Files\Filesystem::initMountPoints(null);
+	}
+
+	public function testNullUserThrowsTwice() {
+		$thrown = 0;
+		try {
+			\OC\Files\Filesystem::initMountPoints(null);
+		} catch (NoUserException $e) {
+			$thrown++;
+		}
+		try {
+			\OC\Files\Filesystem::initMountPoints(null);
+		} catch (NoUserException $e) {
+			$thrown++;
+		}
+		$this->assertEquals(2, $thrown);
+	}
+
+	/**
 	 * Tests that the home storage is used for the user's mount point
 	 */
 	public function testHomeMount() {