Fix errors detected by Dialyzer

src/ejabberd_logger_h.erl

@@ -162,7 +162,7 @@ write_event(Fd, {Time, {warning_msg, _GL, {Pid, Format, Args}}}) ->
 	    file:write(Fd, io_lib:format(T ++ S, []));
 	_ ->
 	    F = add_node("ERROR: ~p - ~p~n", Pid),
-	    file:write(Fd, io:format(T ++ F, [Format,Args]))
+	    file:write(Fd, io_lib:format(T ++ F, [Format,Args]))
     end;
 write_event(_, _) ->
     ok.

src/ejabberd_piefxis.erl

@@ -153,8 +153,8 @@ process_elements(Elements,State) ->
 process_element(El=#xmlel{name=user, ns=_XMLNS},
 		State=#parsing_state{host=Host}) ->
     case add_user(El,Host) of
-	{error, _Other} -> error;
-	_ -> ok
+	ok -> ok;
+	{error, _Other} -> error
     end,
     State;
 
@@ -199,7 +199,7 @@ add_user(El, Domain) ->
     add_user(El, Domain, ?BTL(User), ?BTL(Password)).
 
 %% @spec (El::xmlel(), Domain::string(), User::string(), Password::string())
-%%       -> ok | {atomic, exists} | {error, not_allowed}
+%%       -> ok | {error, ErrorText::string()}
 %% @doc Add a new user to the database.
 %% If user already exists, it will be only updated.
 add_user(El, Domain, User, Password) ->
@@ -221,7 +221,8 @@ add_user(El, Domain, User, Password) ->
 		   end,
 		   El);
 	{error, Other} ->
-	    ?ERROR_MSG("Error adding user ~s@~s: ~p~n", [User, Domain, Other])
+	    ?ERROR_MSG("Error adding user ~s@~s: ~p~n", [User, Domain, Other]),
+	    {error, Other}
     end.
 
 %% @spec (User::string(), Password::string(), Domain::string())

src/web/ejabberd_web_admin.erl

@@ -2241,7 +2241,7 @@ get_node(global, Node, ["update"], Query, Lang) ->
     [?XC("h1", ?T("Update ") ++ atom_to_list(Node))] ++
 	case Res of
 	    ok -> [?XREST("Submitted")];
-	    error -> [?XREST("Bad format")];
+	    {error, ErrorText} -> [?XREST("Error: " ++ ErrorText)];
 	    nothing -> []
 	end ++
 	[?XAE("form", [{"action", ""}, {"method", "post"}],
@@ -2624,9 +2624,11 @@ node_update_parse_query(Node, Query) ->
 		{ok, _} ->
 		    ok;
 		{error, Error} ->
-		    ?ERROR_MSG("~p~n", [Error]);
+		    ?ERROR_MSG("~p~n", [Error]),
+		    {error, io_lib:format("~p", [Error])};
 		{badrpc, Error} ->
-		    ?ERROR_MSG("~p~n", [Error])
+		    ?ERROR_MSG("Bad RPC: ~p~n", [Error]),
+		    {error, "Bad RPC: " ++ io_lib:format("~p", [Error])}
 	    end;
 	_ ->
 	    nothing