M2PA: deal with empty M2PA messages that don't contain MTP3
diff --git a/src/m2pa_codec.erl b/src/m2pa_codec.erl
index 974ffd8..71caf7c 100644
--- a/src/m2pa_codec.erl
+++ b/src/m2pa_codec.erl
@@ -36,6 +36,8 @@
true ->
{undefined, Ret}
end;
+parse_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_USER, 16, <<>>) ->
+ {empty, []};
parse_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_USER, Len, RemainIn) ->
<<Pri:1, _:7, Mtp3Bin/binary>> = RemainIn,
Mtp3 = mtp3_codec:parse_mtp3_msg(Mtp3Bin),
@@ -49,6 +51,8 @@
fwd_seq_nr = FSN, back_seq_nr = BSN,
mtp3 = Mtp3, parameters = Params}}.
+encode_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_USER, empty, _Params) ->
+ <<>>;
encode_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_USER, Mtp3, _Params) when is_binary(Mtp3) ->
<<0:1, 0:7, Mtp3/binary>>;
encode_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_USER, Mtp3, Params) when is_record(Mtp3, mtp3_msg) ->