ensure the view's root is a subfolder of the the default root, not only starting the same

lib/private/files/view.php

@@ -709,7 +709,10 @@ class View {
 			return false;
 		}
 		$defaultRoot = Filesystem::getRoot();
-		return (strlen($this->fakeRoot) >= strlen($defaultRoot)) && (substr($this->fakeRoot, 0, strlen($defaultRoot)) === $defaultRoot);
+		if($this->fakeRoot === $defaultRoot){
+			return true;
+		}
+		return (strlen($this->fakeRoot) > strlen($defaultRoot)) && (substr($this->fakeRoot, 0, strlen($defaultRoot) + 1) === $defaultRoot . '/');
 	}
 
 	private function runHooks($hooks, $path, $post = false) {

tests/lib/files/view.php

@@ -391,4 +391,22 @@ class View extends \PHPUnit_Framework_TestCase {
 		$this->storages[] = $storage;
 		return $storage;
 	}
+
+	/**
+	 * @medium
+	 */
+	function testViewHooksIfRootStartsTheSame() {
+		$storage1 = $this->getTestStorage();
+		$storage2 = $this->getTestStorage();
+		$defaultRoot = \OC\Files\Filesystem::getRoot();
+		\OC\Files\Filesystem::mount($storage1, array(), '/');
+		\OC\Files\Filesystem::mount($storage2, array(), $defaultRoot . '_substorage');
+		\OC_Hook::connect('OC_Filesystem', 'post_write', $this, 'dummyHook');
+
+		$subView = new \OC\Files\View($defaultRoot . '_substorage');
+		$this->hookPath = null;
+
+		$subView->file_put_contents('/foo.txt', 'asd');
+		$this->assertNull($this->hookPath);
+	}
 }