Support negative part-hour TZ values (thanks to Alexander Zhukov)(EJAB-1301)

src/jlib.erl

@@ -561,7 +561,7 @@ rsm_encode_count(Count, Arr)->
 i2l(I) when is_integer(I) -> integer_to_list(I);
 i2l(L) when is_list(L)    -> L.
 
-%% Timezone = utc | {Hours, Minutes}
+%% Timezone = utc | {Sign::string(), {Hours, Minutes}} | {Hours, Minutes}
 %% Hours = integer()
 %% Minutes = integer()
 timestamp_to_iso({{Year, Month, Day}, {Hour, Minute, Second}}, Timezone) ->
@@ -572,6 +572,8 @@ timestamp_to_iso({{Year, Month, Day}, {Hour, Minute, Second}}, Timezone) ->
     Timezone_string =
 	case Timezone of
 	    utc -> "Z";
+	    {Sign, {TZh, TZm}} ->
+		io_lib:format("~s~2..0w:~2..0w", [Sign, TZh, TZm]);
 	    {TZh, TZm} ->
 		Sign = case TZh >= 0 of
 			   true -> "+";

src/mod_time.erl

@@ -76,14 +76,8 @@ process_local_iq(_From, _To, #iq{type = Type, sub_el = SubEl} = IQ) ->
 	    {UTC, UTC_diff} = jlib:timestamp_to_iso(Now_universal, utc),
 	    Seconds_diff = calendar:datetime_to_gregorian_seconds(Now_local)
 	     - calendar:datetime_to_gregorian_seconds(Now_universal),
-            {Hd, Md, _} = case Seconds_diff >= 0 of
-			      true ->
-				  calendar:seconds_to_time(Seconds_diff);
-			      false ->
-				  {Hd0, Md0, Sd0} = calendar:seconds_to_time(-Seconds_diff),
-				  {-Hd0, Md0, Sd0}
-			  end,
-	    {_, TZO_diff} = jlib:timestamp_to_iso({{0, 0, 0}, {0, 0, 0}}, {Hd, Md}),
+	    {Hd, Md, _} = calendar:seconds_to_time(abs(Seconds_diff)),
+	    {_, TZO_diff} = jlib:timestamp_to_iso({{0, 0, 0}, {0, 0, 0}}, {sign(Seconds_diff), {Hd, Md}}),
 	    IQ#iq{type = result,
 		  sub_el = [{xmlelement, "time",
 			     [{"xmlns", ?NS_TIME}],
@@ -93,4 +87,5 @@ process_local_iq(_From, _To, #iq{type = Type, sub_el = SubEl} = IQ) ->
 			       [{xmlcdata, UTC ++ UTC_diff}]}]}]}
     end.
 
-
+sign(N) when N < 0 -> "-";
+sign(_)            -> "+".