MB-100 Fix race condition in test 02-old-index-cleanup.t

Change-Id: I769a3ee0a8bddc0de873b6a282dd85fc58d7a7a8
Reviewed-on: http://review.couchbase.org/20245
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>

src/couch_set_view/test/02-old-index-cleanup.t

@@ -25,7 +25,7 @@ num_docs() -> 1000.
 main(_) ->
     test_util:init_code_path(),
 
-    etap:plan(70),
+    etap:plan(71),
     case (catch test()) of
         ok ->
             etap:end_tests();
@@ -96,7 +96,10 @@ test() ->
         "Old index file deleted before cleanup because group was updated"),
 
     couch_util:shutdown_sync(NewGroupPid),
+    % Let couch_set_view process group process EXIT message
+    ok = timer:sleep(1000),
     NewGroupPid2 = couch_set_view:get_group_pid(test_set_name(), ddoc_id()),
+    etap:isnt(NewGroupPid2, NewGroupPid, "Got different group pid"),
     AllIndexFiles2 = all_index_files(),
     etap:is(lists:member(NewIndexFile, AllIndexFiles2), true,
         "New index file found after group process restart"),