IMPORT-COUNTER-BUG: undatierte Wuerfe als WithoutDate zaehlen, nicht als Created

31 undatierte Wurfchronik-Eintraege (leeres Datumsfeld) wurden bei jedem Lauf
als littersCreated++ gezaehlt, weil ihr Idempotenz-Key (kein Datum) nie in
existingLitterKeySet stand -- aber kein DB-Insert folgte, da date is DateOnly d
false war. Das verfaelschte Arithmetik und Julians Bericht (752 vs 723).

Fix: undatierte Eintraege werden am Schleifenanfang uebersprungen
(littersWithoutDate++, continue) bevor sie in litterIdMap oder den
Created-Zaehler einfliessen. Execute-Block ohne redundante date-Pruefung.
Neues Feld LitterSummary.WithoutDate; Report-Notiz wenn WithoutDate > 0.

Gate: 126/126 C#-Tests, has-pending-model-changes = No.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

GerbilManager.Tests/ImportServiceTests.cs

@@ -507,6 +507,44 @@ namespace GerbilManager.Tests
             }
         }
 
+        [Fact]
+        public async Task UndatedLitters_counted_as_WithoutDate_not_Created()
+        {
+            // COUNTER-BUG regression: litters with no parseable date must go into WithoutDate,
+            // NOT Created. On re-import, Created must be 0 (not 31-phantom-phantom-phantom...).
+            var dir = Path.Combine(Path.GetTempPath(), "undated-" + Guid.NewGuid().ToString("N"));
+            Directory.CreateDirectory(dir);
+            try
+            {
+                // One dated litter, one undated litter (blank date field)
+                File.WriteAllText(Path.Combine(dir, "litters.json"), """
+                [
+                  {"id":"L-dated","litterId":"A","date":"01.02.2020","damName":"Mutter","sireName":"Vater","totalBorn":3,"zuchtnummer":"","note":""},
+                  {"id":"L-undated","litterId":"B","date":"","damName":"Mutter","sireName":"Vater","totalBorn":0,"zuchtnummer":"","note":""}
+                ]
+                """);
+                File.WriteAllText(Path.Combine(dir, "animals.json"), "[]");
+
+                using var db = NewDb();
+
+                // First run
+                var r1 = await new ImportService(db, dir, dir).RunAsync(execute: true);
+                Assert.Equal(2, r1.Litters.InSource);
+                Assert.Equal(1, r1.Litters.Created);        // only the dated one
+                Assert.Equal(0, r1.Litters.AlreadyImported);
+                Assert.Equal(1, r1.Litters.WithoutDate);    // the undated one
+                Assert.Equal(1, await db.Litters.CountAsync());  // only 1 persisted
+
+                // Second run (re-import): dated litter is now existing, undated still WithoutDate
+                var r2 = await new ImportService(db, dir, dir).RunAsync(execute: true);
+                Assert.Equal(0, r2.Litters.Created);        // no phantom "created"
+                Assert.Equal(1, r2.Litters.AlreadyImported);
+                Assert.Equal(1, r2.Litters.WithoutDate);
+                Assert.Equal(1, await db.Litters.CountAsync());  // still only 1 row
+            }
+            finally { try { Directory.Delete(dir, recursive: true); } catch { } }
+        }
+
         [Theory]
         [InlineData("01.02.2020", 2020, 2, 1)]
         [InlineData("5.3.21", 2021, 3, 5)]

GerbilManagerWebAPI/Import/ImportModels.cs

@@ -87,7 +87,7 @@ namespace GerbilManagerWebAPI.Import
 
     public sealed record LitterSummary(int InSource, int Created, int AlreadyImported,
         int DerivedFromChart = 0, int DerivedSkipped = 0, int ParentFksDropped = 0,
-        int ParentFksBackfilled = 0);
+        int ParentFksBackfilled = 0, int WithoutDate = 0);
 
     public sealed record AnimalSummary(
         int InSource,

GerbilManagerWebAPI/Import/ImportService.cs

@@ -94,11 +94,17 @@ namespace GerbilManagerWebAPI.Import
             var damNames = litters.Select(l => Normalize(StripZucht(l.DamName))).Where(s => s.Length > 0).ToHashSet();
 
             // ---- litters: create map source.id -> Litter (for high-confidence animal links) ----
-            int littersCreated = 0, littersExisting = 0;
+            // COUNTER-BUG FIX: undated litters (31 in the Wurfchronik) have no parseable date,
+            // so their existingLitterKeySet key was always "" → they were always counted as
+            // "created" even though the execute block skipped them (date is DateOnly d = false).
+            // Fix: skip undated litters early — they can never be created or linked to animals.
+            int littersCreated = 0, littersExisting = 0, littersWithoutDate = 0;
             var litterIdMap = new Dictionary<string, Guid>();    // source litter id -> Litter.Id
             foreach (var sl in litters)
             {
                 var date = ParseDate(sl.Date);
+                if (date is null) { littersWithoutDate++; continue; }   // undated: skip entirely
+
                 var name = $"Wurf {sl.LitterId}".Trim();
                 var key = $"{name}|{date:yyyy-MM-dd}";
                 if (existingLitterKeySet.Contains(key)) { littersExisting++; continue; }
@@ -106,19 +112,19 @@ namespace GerbilManagerWebAPI.Import
                 var id = Guid.NewGuid();
                 litterIdMap[sl.Id] = id;
                 littersCreated++;
-                if (execute && date is DateOnly d)
+                if (execute)
                 {
                     _db.Litters.Add(new Litter
                     {
                         Id = id,
                         Name = name,
-                        Date = d,
+                        Date = date.Value,
                         TotalBorn = sl.TotalBorn,
                         Notes = string.IsNullOrWhiteSpace(sl.Note) ? null : sl.Note,
                         PairingCode = string.IsNullOrWhiteSpace(sl.Zuchtnummer) ? null : sl.Zuchtnummer,
                     });
                 }
-                if (samples.Count < 8 && date is not null)
+                if (samples.Count < 8)
                     samples.Add($"Wurf: {name} ({sl.Date}) — {sl.DamName} × {sl.SireName}");
             }
             if (execute) await _db.SaveChangesAsync();
@@ -454,6 +460,8 @@ namespace GerbilManagerWebAPI.Import
                 if (execute && parentFksBackfilled > 0) await _db.SaveChangesAsync();
             }
 
+            if (littersWithoutDate > 0)
+                notes.Add($"Würfe ohne Datum: {littersWithoutDate} Wurfchronik-Einträge ohne parsbares Geburtsdatum übersprungen (weder erstellt noch verknüpft).");
             notes.Add("Quarantäne (kein Import): Konflikte + Stubs ohne Geburtsdatum + unsichere Wurf-Zuordnungen — warten auf die Prüfung durch die Züchterin.");
             if (parentLinksAdded > 0)
                 notes.Add($"Stammbaum-Diagramm: {parentLinksAdded} Tiere über Eltern-Verknüpfung einem (abgeleiteten) Wurf zugeordnet ({derivedLitters} abgeleitete Würfe).");
@@ -468,7 +476,7 @@ namespace GerbilManagerWebAPI.Import
 
             return new ImportReport(
                 Executed: execute,
-                Litters: new LitterSummary(litters.Count, littersCreated, littersExisting, derivedLitters, derivedLittersSkipped, litterParentFksDropped, parentFksBackfilled),
+                Litters: new LitterSummary(litters.Count, littersCreated, littersExisting, derivedLitters, derivedLittersSkipped, litterParentFksDropped, parentFksBackfilled, littersWithoutDate),
                 Animals: new AnimalSummary(
                     animals.Count, animalsCreated, linked, fbMatched, fbUnmatched, animalsExisting,
                     new QuarantineSummary(conflicts, stubs, dateOnly, ambiguous, conflicts + stubs),