OTP-8358 A race bug affecting pg2:get_local_members/1 has been fixed. The

          bug was introduced in R13B03.

1 files changed, 10 insertions, 7 deletions

diff --git a/lib/kernel/src/pg2.erl b/lib/kernel/src/pg2.erl
index fc9508a194..cb9fec2ffe 100644
--- a/lib/kernel/src/pg2.erl
+++ b/lib/kernel/src/pg2.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1997-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 -module(pg2).
@@ -334,8 +334,11 @@ local_group_members(Name) ->
         P <- member_in_group(Pid, Name)].
 
 member_in_group(Pid, Name) ->
-    [{{member, Name, Pid}, N}] = ets:lookup(pg2_table, {member, Name, Pid}),
-    lists:duplicate(N, Pid).
+    case ets:lookup(pg2_table, {member, Name, Pid}) of
+        [] -> [];
+        [{{member, Name, Pid}, N}] ->
+            lists:duplicate(N, Pid)
+    end.
 
 member_groups(Pid) ->
     [Name || [Name] <- ets:match(pg2_table, {{pid, Pid, '$1'}})].