[stable10] Handle invalid storage when getting storage root id

lib/private/Files/Mount/MountPoint.php

@@ -245,9 +245,20 @@ public function getOptions() {
 	/**
 	 * Get the file id of the root of the storage
 	 *
-	 * @return int
+	 * @return int storage numeric id or -1 in case of invalid storage
 	 */
 	public function getStorageRootId() {
-		return (int)$this->getStorage()->getCache()->getId('');
+		$storage = $this->getStorage();
+		if ($storage === null || $this->invalidStorage) {
+			return -1;
+		}
+
+		$cache = $storage->getCache();
+
+		if ($cache === null) {
+			return -1;
+		}
+
+		return (int)$cache->getId('');
 	}
 }

lib/public/Files/Mount/IMountPoint.php

@@ -98,7 +98,7 @@ public function getOptions();
 	/**
 	 * Get the file id of the root of the storage
 	 *
-	 * @return int
+	 * @return int storage numeric id or -1 in case of invalid storage
 	 * @since 9.1.0
 	 */
 	public function getStorageRootId();

tests/lib/Files/Mount/MountPointTest.php

@@ -11,10 +11,18 @@
 class MountPointTest extends \Test\TestCase {
 
 	public function testGetStorage() {
+		$cache = $this->createMock('\OC\Files\Cache\Cache');
+		$cache->expects($this->once())
+			->method('getId')
+			->will($this->returnValue(123));
+
 		$storage = $this->createMock('\OCP\Files\Storage');
 		$storage->expects($this->once())
 			->method('getId')
-			->will($this->returnValue(123));
+			->will($this->returnValue('home:12345'));
+		$storage->expects($this->any())
+			->method('getCache')
+			->will($this->returnValue($cache));
 
 		$loader = $this->createMock('\OCP\Files\Storage\IStorageFactory');
 		$loader->expects($this->once())
@@ -30,7 +38,8 @@ public function testGetStorage() {
 		);
 
 		$this->assertEquals($storage, $mountPoint->getStorage());
-		$this->assertEquals(123, $mountPoint->getStorageId());
+		$this->assertEquals('home:12345', $mountPoint->getStorageId());
+		$this->assertEquals(123, $mountPoint->getStorageRootId());
 		$this->assertEquals('/mountpoint/', $mountPoint->getMountPoint());
 
 		$mountPoint->setMountPoint('another');
@@ -67,7 +76,31 @@ public function testInvalidStorage() {
 
 		$this->assertNull($mountPoint->getStorage());
 
+		$this->assertEquals(-1, $mountPoint->getStorageRootId());
+
 		// storage wrapper never called
 		$this->assertFalse($called);
 	}
+
+	public function testGetRootIdNullCache() {
+		$storage = $this->createMock('\OCP\Files\Storage');
+		$storage->expects($this->any())
+			->method('getCache')
+			->will($this->returnValue(null));
+
+		$loader = $this->createMock('\OCP\Files\Storage\IStorageFactory');
+		$loader->expects($this->once())
+			->method('getInstance')
+			->will($this->returnValue($storage));
+
+		$mountPoint = new \OC\Files\Mount\MountPoint(
+			// just use this because a real class is needed
+			'\Test\Files\Mount\MountPointTest',
+			'/mountpoint',
+			null,
+			$loader
+		);
+
+		$this->assertEquals(-1, $mountPoint->getStorageRootId());
+	}
 }