Keep an excluded contact out of the score the way N1MM does

Three things were wrong with a contact the operator takes out of the claimed
score. The decompiled reference gives the rule in four places:

- `Contest.cs:437` returns zero points when `IsClaimedQso` is 0.
- `ContestInstance.cs:307` builds the where clause `CLAIMEDQSO = 1`, which the
  dupe search (`DBSupport.cs:1189`) and the multiplier search
  (`DBSupport.cs:1327`) both use, so an unclaimed contact takes nothing away
  from a later one.
- The score query (`DBSupport.cs:1807`) adds `ContactType <> 'D'`, which the
  other two do not. A contact marked as a dupe is therefore still searched for
  dupes and multipliers, and is left out of the score alone.
- `Contact.cs:1563`, `3307` and `3881` write `X-QSO:` rather than dropping the
  contact from the Cabrillo file.

`ContestLog` scored an unclaimed contact in full, and the Cabrillo writer left
it out of the file. `Qso.IsInScore` now holds the score rule and
`StatisticsPivot` uses it instead of its own copy.

The same reference also fixes the sent serial in three Cabrillo exporters.
ARRL 10M, Ukrainian DX and YO DX HF formatted the sent exchange from the
station rather than the contact, so a DX entrant exported `001` on every line.
N1MM reads the contact's own number: `CArrl10m.cs:122` writes it unpadded,
`CUkrainian.cs:232` and `CYOHFDX.cs:167` pad it to three digits.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015NZkFxHde1iifAQemFTHxf

src/Nonemm.Contests/ContestLog.cs

@@ -47,6 +47,10 @@ public sealed class ContestLog
     /// What logging this contact right now would do, without logging it.
     public Verdict Judge(Qso candidate)
     {
+        if (!candidate.IsClaimed)
+        {
+            return new Verdict(false, 0, []);
+        }
         QsoContext context = ContextFor(candidate);
         if (!contest.IsContact(candidate))
         {
@@ -164,9 +168,23 @@ public sealed class ContestLog
         IsMultiplier3 = claimed.Any(m => m.Index == 3),
     };
 
+    /// Adds the contact to the score and to the indexes that answer "worked
+    /// before?" and "new multiplier?". An unclaimed contact enters neither:
+    /// N1MM scores it as zero and leaves it out of both searches, so it takes
+    /// nothing away from a later contact with the same call or multiplier. A
+    /// contact marked as a dupe is the other way round — N1MM searches for
+    /// dupes and multipliers among it, and leaves it out of the score alone.
     private void Index(Qso qso, Verdict verdict)
     {
-        tally.AddQso(verdict.Points);
+        if (!qso.IsClaimed)
+        {
+            return;
+        }
+        bool counts = qso.IsInScore;
+        if (counts)
+        {
+            tally.AddQso(verdict.Points);
+        }
         if (!contest.IsContact(qso))
         {
             return;
@@ -175,7 +193,10 @@ public sealed class ContestLog
         foreach (Multiplier multiplier in verdict.NewMultipliers)
         {
             claimedMultipliers.Add(MultiplierKey(multiplier, qso));
-            tally.AddMultiplier(multiplier);
+            if (counts)
+            {
+                tally.AddMultiplier(multiplier);
+            }
         }
     }
 

src/Nonemm.Contests/Rules/Arrl10Metre.cs

@@ -54,6 +54,13 @@ public sealed class Arrl10Metre : Contest
             ? me.State.Length > 0 ? me.State : me.Province
             : "001";
 
+    /// What went out on this contact. A US or Canadian station sends the same
+    /// state or province every time; everyone else sends a serial, and ARRL
+    /// asks for the serial of that contact, so the Cabrillo file reads the
+    /// contact's own number and not the first one. N1MM sends it unpadded.
+    private string SentExchangeOn(Qso qso, StationInfo me) =>
+        SendsState(me.CountryPrefix) ? SentExchangeFor(me) : $"{qso.SentNumber}";
+
     public int PointsFor(QsoContext qso) => qso.ModeCategory == ModeCategory.Cw ? 4 : 2;
 
     public IReadOnlyList<Multiplier> MultipliersFor(QsoContext qso)
@@ -75,7 +82,7 @@ public sealed class Arrl10Metre : Contest
             [
                 new CabrilloField(me.Callsign, 13),
                 new CabrilloField(qso.SentReport, 3),
-                new CabrilloField(SentExchangeFor(me), 6),
+                new CabrilloField(SentExchangeOn(qso, me), 6),
             ],
             [
                 new CabrilloField(qso.Call.Text, 13),

src/Nonemm.Contests/Rules/UkrainianDx.cs

@@ -56,6 +56,13 @@ public sealed class UkrainianDx : Contest
     public string SentExchangeFor(StationInfo me) =>
         IsUkrainian(me.CountryPrefix) ? me.County : "001";
 
+    /// What went out on this contact. A Ukrainian station sends the same
+    /// oblast every time; everyone else sends a serial, so the Cabrillo file
+    /// reads the contact's own number and not the first one. N1MM pads it to
+    /// three digits.
+    private string SentExchangeOn(Qso qso, StationInfo me) =>
+        IsUkrainian(me.CountryPrefix) ? me.County : $"{qso.SentNumber:000}";
+
     public int PointsFor(QsoContext qso)
     {
         if (IsUkrainian(qso.CountryPrefix))
@@ -93,7 +100,7 @@ public sealed class UkrainianDx : Contest
             [
                 new CabrilloField(me.Callsign, 13),
                 new CabrilloField(qso.SentReport, 3),
-                new CabrilloField(SentExchangeFor(me), 6),
+                new CabrilloField(SentExchangeOn(qso, me), 6),
             ],
             [
                 new CabrilloField(qso.Call.Text, 13),

src/Nonemm.Contests/Rules/YoDxHf.cs

@@ -55,6 +55,13 @@ public sealed class YoDxHf : Contest
 
     public string SentExchangeFor(StationInfo me) => me.CountryPrefix == "YO" ? me.County : "001";
 
+    /// What went out on this contact. A YO station sends the same county
+    /// every time; everyone else sends a serial, so the Cabrillo file reads the
+    /// contact's own number and not the first one. N1MM pads it to three
+    /// digits.
+    private string SentExchangeOn(Qso qso, StationInfo me) =>
+        me.CountryPrefix == "YO" ? me.County : $"{qso.SentNumber:000}";
+
     public int PointsFor(QsoContext qso)
     {
         if (qso.CountryPrefix == "YO")
@@ -88,7 +95,7 @@ public sealed class YoDxHf : Contest
             [
                 new CabrilloField(me.Callsign, 13),
                 new CabrilloField(qso.SentReport, 3),
-                new CabrilloField(SentExchangeFor(me), 6),
+                new CabrilloField(SentExchangeOn(qso, me), 6),
             ],
             [
                 new CabrilloField(qso.Call.Text, 13),

src/Nonemm.Core/Qso.cs

@@ -95,6 +95,12 @@ public sealed record Qso
     /// Cleared when the operator excludes a contact from the claimed score.
     public bool IsClaimed { get; init; } = true;
 
+    /// Counted in the score. N1MM sums points, contacts and multipliers over
+    /// the claimed contacts that are not marked as a dupe. Nothing here writes
+    /// the `D` contact type, but a log N1MM wrote can carry it.
+    public bool IsInScore =>
+        IsClaimed && !ContactType.Equals("D", StringComparison.OrdinalIgnoreCase);
+
     public Band? Band => Bands.ForFrequency(Frequency);
 
     public static string NewId() => Guid.NewGuid().ToString("N");

src/Nonemm.Formats/Cabrillo/CabrilloWriter.cs

@@ -54,7 +54,7 @@ public sealed class CabrilloWriter
         }
         Line(text, "CREATED-BY", header.CreatedBy);
 
-        foreach (Qso qso in qsos.Where(q => q.IsClaimed).OrderBy(q => q.TimestampUtc))
+        foreach (Qso qso in qsos.OrderBy(q => q.TimestampUtc))
         {
             text.Append(QsoLine(qso)).Append("\r\n");
         }
@@ -65,7 +65,7 @@ public sealed class CabrilloWriter
     public string QsoLine(Qso qso)
     {
         CabrilloExchange exchange = contest.CabrilloExchange(qso, me, entry);
-        StringBuilder line = new(contest.IsContact(qso) ? "QSO: " : "QTC: ");
+        StringBuilder line = new(RecordName(qso));
         line.Append(CabrilloBands.Designator(qso.Frequency).PadLeft(5)).Append(' ');
         line.Append(qso.Mode.CabrilloCode.PadRight(2)).Append(' ');
         line.Append(qso.TimestampUtc.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture)).Append(' ');
@@ -79,6 +79,18 @@ public sealed class CabrilloWriter
         return line.ToString();
     }
 
+    /// A contact the operator has excluded from the claimed score is still
+    /// written, under `X-QSO:` rather than `QSO:`. That is what N1MM writes,
+    /// and the sponsors read it as a contact the entrant is not claiming.
+    private string RecordName(Qso qso)
+    {
+        if (!contest.IsContact(qso))
+        {
+            return "QTC: ";
+        }
+        return qso.IsClaimed ? "QSO: " : "X-QSO: ";
+    }
+
     /// Every column is the width the sponsor asks for and one space, and a
     /// value longer than its column is cut, which is what N1MM writes.
     private static void Append(StringBuilder line, IReadOnlyList<CabrilloField> fields)

src/Nonemm.Session/StatisticsPivot.cs

@@ -57,7 +57,7 @@ public sealed class StatisticsPivot
         SortedSet<PivotKey> columns = [];
         foreach (Qso qso in qsos)
         {
-            if (!includeDupes && !IsCounted(qso))
+            if (!includeDupes && !qso.IsInScore)
             {
                 continue;
             }
@@ -102,10 +102,4 @@ public sealed class StatisticsPivot
     public int Total { get; }
 
     public bool IsEmpty => Rows.Count == 0;
-
-    /// N1MM counts a contact when it is in the claimed score and is not marked
-    /// as a dupe. Nothing in this program writes the `D` contact type, but a log
-    /// N1MM wrote can carry it.
-    private static bool IsCounted(Qso qso) =>
-        qso.IsClaimed && !qso.ContactType.Equals("D", StringComparison.OrdinalIgnoreCase);
 }