mod_mam: more checks for database failure

src/mod_mam.erl

@@ -64,7 +64,7 @@
 -callback store(xmlel(), binary(), {binary(), binary()}, chat | groupchat,
 		jid(), binary(), recv | send, integer()) -> ok | any().
 -callback write_prefs(binary(), binary(), #archive_prefs{}, binary()) -> ok | any().
--callback get_prefs(binary(), binary()) -> {ok, #archive_prefs{}} | error.
+-callback get_prefs(binary(), binary()) -> {ok, #archive_prefs{}} | error | {error, db_failure}.
 -callback select(binary(), jid(), jid(), mam_query:result(),
 		 #rsm_set{} | undefined, chat | groupchat) ->
     {[{binary(), non_neg_integer(), xmlel()}], boolean(), count()} |
@@ -599,25 +599,32 @@ process_iq(#iq{from = #jid{luser = LUser, lserver = LServer},
 	    xmpp:make_error(IQ, xmpp:err_internal_server_error(Txt, Lang))
     end;
 process_iq(#iq{from = #jid{luser = LUser, lserver = LServer},
-	       to = #jid{lserver = LServer},
+	       to = #jid{lserver = LServer}, lang = Lang,
 	       type = get, sub_els = [#mam_prefs{xmlns = NS}]} = IQ) ->
-    Prefs = get_prefs(LUser, LServer),
+    case get_prefs(LUser, LServer) of
+	{ok, Prefs} ->
 	    PrefsEl = prefs_el(Prefs#archive_prefs.default,
 			       Prefs#archive_prefs.always,
 			       Prefs#archive_prefs.never,
 			       NS),
 	    xmpp:make_iq_result(IQ, PrefsEl);
+	{error, _} ->
+	    Txt = <<"Database failure">>,
+	    xmpp:make_error(IQ, xmpp:err_internal_server_error(Txt, Lang))
+    end;
 process_iq(IQ) ->
     xmpp:make_error(IQ, xmpp:err_not_allowed()).
 
 process_iq(LServer, #iq{from = #jid{luser = LUser}, lang = Lang,
 			sub_els = [SubEl]} = IQ, MsgType) ->
-    case MsgType of
+    Ret = case MsgType of
 	      chat ->
 		  maybe_activate_mam(LUser, LServer);
 	      {groupchat, _Role, _MUCState} ->
 		  ok
 	  end,
+    case Ret of
+	ok ->
 	    case SubEl of
 		#mam_query{rsm = #rsm_set{index = I}} when is_integer(I) ->
 		    Txt = <<"Unsupported <index/> element">>,
@@ -630,6 +637,10 @@ process_iq(LServer, #iq{from = #jid{luser = LUser}, lang = Lang,
 			{error, Err} ->
 			    xmpp:make_error(IQ, Err)
 		    end
+	    end;
+	{error, _} ->
+	     Txt = <<"Database failure">>,
+	    xmpp:make_error(IQ, xmpp:err_internal_server_error(Txt, Lang))
     end.
 
 -spec should_archive(message(), binary()) -> boolean().
@@ -823,7 +834,8 @@ may_enter_room(From, MUCState) ->
 -spec store_msg(message(), binary(), binary(), jid(), send | recv)
       -> ok | pass | any().
 store_msg(Pkt, LUser, LServer, Peer, Dir) ->
-    Prefs = get_prefs(LUser, LServer),
+    case get_prefs(LUser, LServer) of
+	{ok, Prefs} ->
 	    case {should_archive_peer(LUser, LServer, Prefs, Peer), Pkt} of
 		{true, #message{meta = #{sm_copy := true}}} ->
 		    ok; % Already stored.
@@ -841,6 +853,9 @@ store_msg(Pkt, LUser, LServer, Peer, Dir) ->
 		    end;
 		{false, _} ->
 		    pass
+	    end;
+	{error, _} ->
+	    pass
     end.
 
 -spec store_muc(mod_muc_room:state(), message(), jid(), jid(), binary())
@@ -895,18 +910,20 @@ get_prefs(LUser, LServer) ->
 	  end,
     case Res of
 	{ok, Prefs} ->
-	    Prefs;
+	    {ok, Prefs};
+	{error, _} ->
+	    {error, db_failure};
 	error ->
 	    ActivateOpt = gen_mod:get_module_opt(
 			    LServer, ?MODULE,
 			    request_activates_archiving),
 	    case ActivateOpt of
 		true ->
-		    #archive_prefs{us = {LUser, LServer}, default = never};
+		    {ok, #archive_prefs{us = {LUser, LServer}, default = never}};
 		false ->
 		    Default = gen_mod:get_module_opt(
 				LServer, ?MODULE, default),
-		    #archive_prefs{us = {LUser, LServer}, default = Default}
+		    {ok, #archive_prefs{us = {LUser, LServer}, default = Default}}
 	    end
     end.
 
@@ -935,6 +952,8 @@ maybe_activate_mam(LUser, LServer) ->
 	    case Res of
 		{ok, _Prefs} ->
 		    ok;
+		{error, _} ->
+		    {error, db_failure};
 		error ->
 		    Default = gen_mod:get_module_opt(
 				LServer, ?MODULE, default),