[PATCH 1 of 3 follow-up] test-revset: check that #generations[1:-1] doesn't result in any errors

[Anton Shestakov]

# HG changeset patch
# User Anton Shestakov <av6 at dwimlabs.net>
# Date 1548476405 -28800
#      Sat Jan 26 12:20:05 2019 +0800
# Node ID b57f637ff71ae812fe78722666fec025cbf8b75e
# Parent  431cf2c8c83969a68d132d6ba92af1998e147927
test-revset: check that #generations[1:-1] doesn't result in any errors

diff --git a/tests/test-revset.t b/tests/test-revset.t
--- a/tests/test-revset.t
+++ b/tests/test-revset.t
@@ -1300,6 +1300,7 @@ test ancestors/descendants relation subs
   5
   6
   7
+  $ log 'tip#generations[1:-1]'
 
   $ hg debugrevspec -p parsed 'roots(:)#g[2]'
   * parsed: