Allow groups where the first entry is a group

[twoi]

rather than a field.

Currently, this results in the GroupDelimiterTagException "Group 123's first entry does not start with delimiter 0"

N.B. I have tested this only very lightly so far, and it addresses the problem

[gbirchmeier]

If I understand you right, I'm fairly sure this isn't legal FIX. Do you have a real-world example that I can see?

[twoi]

Not sure if it is "legal", but it's in the upcoming spec of an exchange and we need to implement it.

Here is the specification of the payload of that custom message which I couldn't get to run, before applying this PR:

 Tag   Tag   Tag   Tag   Field Name              Type        Req'd 
-------------------------------------------------------------------
 1666                    RiskLimitRequestID      String      Y     
 1677                    NoPartyRiskLimits       NumInGroup  Y     
 ->    1324              ListUpdateAction        char        Y     
 ->    1669              NoRiskLimits            NumInGroup  Y     
 ->    ->    1529        NoRiskLimitTypes        NumInGroup  Y     
 ->    ->    ->    1530  RiskLimitType           int         Y     
 ->    ->    ->    1531  RiskLimitAmount         Amt         N     
 ->    ->    1534        NoRiskInstrumentScopes  NumInGroup  N     
 ->    ->    ->    1536  InstrumentScopeSymbol   String      N     

It fails parsing group 1669, because there is no field directly following the NumInGroup field, but a group.

[gbirchmeier]

I will take a look tomorrow. On second look, I see no logical reason why a group counter can't also be the delimiter of the parent group.

[twoi]

@gbirchmeier If tomorrow never comes... :-P Just joking.

It's not urgent for me anyway, as I am building from a fork of quickfixn, but I wanted to let you know that I've let this run for these 18 days now in our test environment, and there were no problems with it.

[gbirchmeier]

Haha, oops! Still got the tab open. I hope to get back to it before too long.