only run archive tests if the test data is available

apps/files_archive/tests/tar.php

@@ -8,6 +8,7 @@
 
 require_once('archive.php');
 
+if(is_dir(OC::$SERVERROOT.'/apps/files_archive/tests/data')){
 	class Test_Archive_TAR extends Test_Archive{
 		protected function getExisting(){
 			$dir=OC::$SERVERROOT.'/apps/files_archive/tests/data';
@@ -18,3 +19,6 @@ class Test_Archive_TAR extends Test_Archive{
 			return new OC_Archive_TAR(OC_Helper::tmpFile('.tar.gz'));
 		}
 	}
+}else{
+	abstract class Test_Archive_TAR extends Test_Archive{}
+}

apps/files_archive/tests/zip.php

@@ -8,6 +8,7 @@
 
 require_once('archive.php');
 
+if(is_dir(OC::$SERVERROOT.'/apps/files_archive/tests/data')){
 	class Test_Archive_ZIP extends Test_Archive{
 		protected function getExisting(){
 			$dir=OC::$SERVERROOT.'/apps/files_archive/tests/data';
@@ -18,3 +19,6 @@ class Test_Archive_ZIP extends Test_Archive{
 			return new OC_Archive_ZIP(OC_Helper::tmpFile('.zip'));
 		}
 	}
+}else{
+	abstract class Test_Archive_ZIP extends Test_Archive{}
+}