Guard against empty list Rotating an empty list gives badarith so add a guard clause, since the result of rotating an empty list is well known.
BugzID: 17801 Project: http://git-wip-us.apache.org/repos/asf/couchdb-mem3/repo Commit: http://git-wip-us.apache.org/repos/asf/couchdb-mem3/commit/beb54c9f Tree: http://git-wip-us.apache.org/repos/asf/couchdb-mem3/tree/beb54c9f Diff: http://git-wip-us.apache.org/repos/asf/couchdb-mem3/diff/beb54c9f Branch: refs/heads/import Commit: beb54c9fdf5e301c9c2bfb95ca3b1dfcf7d6397a Parents: cfbb280 Author: Robert Newson <robert.new...@cloudant.com> Authored: Thu Mar 7 15:29:35 2013 -0600 Committer: Robert Newson <robert.new...@cloudant.com> Committed: Thu Mar 7 15:37:55 2013 -0600 ---------------------------------------------------------------------- src/mem3.erl | 2 ++ 1 file changed, 2 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/couchdb-mem3/blob/beb54c9f/src/mem3.erl ---------------------------------------------------------------------- diff --git a/src/mem3.erl b/src/mem3.erl index 18257ba..10dfac0 100644 --- a/src/mem3.erl +++ b/src/mem3.erl @@ -222,6 +222,8 @@ choose_ushards(DbName, Shards) -> {_, Result} = lists:foldl(Fun, {0, []}, Groups), Result. +rotate_list(_DbName, []) -> + []; rotate_list(DbName, List) -> {H, T} = lists:split(erlang:crc32(DbName) rem length(List), List), T ++ H.
