Correct Null Key Suppression

internal/topdata/convert.go

@@ -453,6 +453,17 @@ func convertedRowKeyCandidates(row map[string]any, preferred []string) []string
 	fields := preferred
 	if len(fields) == 0 {
 		fields = []string{"LABEL", "Label", "Name"}
+	} else {
+		for _, field := range fields {
+			value, ok := row[field]
+			if !ok {
+				return nil
+			}
+			text := strings.TrimSpace(format2DAValue(value))
+			if text == "" || text == nullValue {
+				return nil
+			}
+		}
 	}
 	values := make([]string, 0, len(fields))
 	seen := map[string]struct{}{}

internal/topdata/convert_test.go

@@ -177,6 +177,31 @@ func TestRunConvertCommand2DAToJSONInfersOutputDatasetKeysFromConfig(t *testing.
 	}
 }
 
+func TestConvert2DAToJSONSkipsConfiguredKeysWhenAnyKeyFieldIsNull(t *testing.T) {
+	result, err := convert2DAToJSON(parsed2DA{
+		Columns: []string{"LABEL", "RESREF", "STRREF"},
+		Rows: []map[string]any{
+			{"id": 309, "LABEL": "Unused", "RESREF": "unused", "STRREF": 1},
+			{"id": 310, "LABEL": nullValue, "RESREF": "unused", "STRREF": 2},
+		},
+	}, "topdata/data/soundset/base.json", convertOptions{
+		Namespace:     "soundset",
+		KeyFields:     []string{"RESREF", "LABEL"},
+		CollisionMode: "error",
+	})
+	if err != nil {
+		t.Fatalf("convert2DAToJSON failed: %v", err)
+	}
+
+	rows := result["rows"].([]map[string]any)
+	if got := rows[0]["key"]; got != "soundset:unused" {
+		t.Fatalf("expected first row key to use the primary configured key field, got %#v", got)
+	}
+	if _, ok := rows[1]["key"]; ok {
+		t.Fatalf("expected second row to remain unkeyed when one configured key field is null, got %#v", rows[1]["key"])
+	}
+}
+
 func TestRunConvertCommandFailsOnUnkeyedRows(t *testing.T) {
 	root := testProjectRoot(t)
 	writeFile(t, filepath.Join(root, "nwn-tool.json"), `{