Fix timeout in couchdb_views_test for couchdb_1283

I believe the race here was that the query could return before the
actual index updating process exited. Then it was just a race to
creating a database before the monitor is released.

If we do end up creating the database before the monitor is released
then the database we want to have closed ends up being ignored as its
not idle. The second two created databases then don't end up forcing the
database from couch_server's LRU which leads us to the timeout waiting
for DatabaseMonRef to fire.

Fixes #655

src/couch/test/couchdb_views_tests.erl

@@ -345,6 +345,13 @@ couchdb_1283() ->
         % monitor db and index pids
         {ok, DDPid} = couch_index_server:get_index(
             couch_mrview_index, MDb1#db.name, <<"_design/foo">>),
+
+        % Our query could have run after a partial update
+        % so we need to make sure that the updater has
+        % exited and released its monitor on the database
+        % fd.
+        wait_for_updater_exit(DDPid),
+
         DesignDocMonRef = erlang:monitor(process, DDPid),
         DatabaseMonRef = erlang:monitor(process, MDb1#db.main_pid),
 
@@ -629,6 +636,26 @@ wait_view_compact_done(DbName, DDocId, N) ->
             wait_view_compact_done(DbName, DDocId, N - 1)
     end.
 
+% This is a bit of a dirty hack fishing through various
+% state records but at least its better than putting
+% a sleep on it and calling it fixed.
+wait_for_updater_exit(DDPid) ->
+    % #st record from couch_index.erl
+    IdxState = sys:get_state(DDPid),
+    UpdaterPid = element(4, IdxState),
+
+    % #st record from couch_index_updater.erl
+    UpdaterState = sys:get_state(UpdaterPid),
+    RunnerPid = element(4, UpdaterState),
+
+    % RunnerPid can be nil, undefined, or a pid so
+    % just check if its a pid and wait on it to
+    % exit
+    if not is_pid(RunnerPid) -> ok; true ->
+        Ref = erlang:monitor(process, RunnerPid),
+        receive {'DOWN', Ref, _, _, _} -> ok end
+    end.
+
 spawn_writer(DbName) ->
     Parent = self(),
     spawn(fun() ->