Correctlly formated message causing internal exception when validating before sending it to our code

[adairvargas]

Hello QuickFix Team

Currently we are working on a system to process allocation confirmations (Message started by a J message). We are having an issue with a specific message that is causing the internal QuickFix thread before we can control the exception.

When we receive the initial J message, we process it with no issue, but when we receive the final responses in the flow, an AU message, from the routing party, we see that the NoHops group in the header appears to be not correctly processed.
Here the messages:

Correctly processed:
8=FIX.4.4�9=503�35=J�56=FINA44�115=BLKALD44�50=BLKALD44�627=1�628=ATR�629=20230614-13:26:15�630=862 �34=1259�49=REFIN44�52=20230614-13:26:14�70=G1010018643�71=0�626=1�857=0�54=1�55=VOD�48=GB00BH4HKS39�22=4�167=CS�225=19881026�107=VODAFONE GROUP PLC�53=10.0�423=2�6=0.83000000�15=GBP�453=2�448=BLKSUS30TST�447=D�452=13�448=549300E7R8O8EHE8SN83�447=N�452=1�75=20230613�60=20230613-00:00:00.000�64=20230615�381=8.30�118=8.35�78=1�79=E_QISEM�80=10.0�467=42823-590993�12=0.01�13=3�154=8.35�136=1�137=0.04�138=GBP�139=7�891=0�10=212�

Causes Exception:
8=FIX.4.4�9=213�35=AU�56=FINA44�115=BLKALD44�50=BLKALD44�627=1�628=ATR�629=20230614-16:39:40�630=2264�34=1706�49=REFIN44�52=20230614-16:39:39�664=CID_00014�75=20230613�60=20230614-16:39:40�940=2�58=This trade has been confirmed.�10=237�

The exception is:
Session FIX.4.4:FINA44->REFIN44 disconnecting: System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary. at System.Collections.Generic.Dictionary``2.get_Item(TKey key) at QuickFix.DataDictionary.DataDictionary.Iterate(FieldMap map, String msgType) at QuickFix.DataDictionary.DataDictionary.Validate(Message message, DataDictionary sessionDataDict, DataDictionary appDataDict, String beginString, String msgType) at QuickFix.Session.Next(MessageBuilder msgBuilder) at QuickFix.Session.NextMessage(String msgStr) at QuickFix.SocketInitiatorThread.ProcessStream() at QuickFix.SocketInitiatorThread.Read()

Right now we had to put UseDataDictionary=N, ValidateFieldsOutOfOrder=N and also the temp fix mentioned in the issue 709.

[gbirchmeier]

This is #313. QF/n doesn't process repeating groups in the header (and NoHops is the only one of those).