Treat prefixes correct for text sigles

Change-Id: I710912f4681f16d866410ead0e050afe55c61b68
diff --git a/t/archive.t b/t/archive.t
index 0a17165..1cd3c00 100644
--- a/t/archive.t
+++ b/t/archive.t
@@ -47,8 +47,10 @@
 $archive = KorAP::XML::Archive->new($file);
 ok(!$archive->check_prefix, 'Archive has no prefix');
 
-
-# TODO: Test attaching!
+# No leading '.'
+$file = catfile(dirname(__FILE__), 'corpus','archive_rei.zip');
+$archive = KorAP::XML::Archive->new($file);
+ok(!$archive->check_prefix, 'Archive has no dot prefix');
 
 done_testing;