patch 7.4.1547
Problem:    Getting a cterm highlight attribute that is not set results in the
            string "-1".
Solution:   Return an empty string. (Taro Muraoka)
diff --git a/src/testdir/test_alot.vim b/src/testdir/test_alot.vim
index 6071756..a1d819d 100644
--- a/src/testdir/test_alot.vim
+++ b/src/testdir/test_alot.vim
@@ -16,5 +16,6 @@
 source test_searchpos.vim
 source test_set.vim
 source test_sort.vim
+source test_syn_attr.vim
 source test_undolevels.vim
 source test_unlet.vim