Index: applications/editors/josm/plugins/tagging-preset-tester/src/org/openstreetmap/josm/plugins/taggingpresettester/TaggingPresetTester.java
===================================================================
--- applications/editors/josm/plugins/tagging-preset-tester/src/org/openstreetmap/josm/plugins/taggingpresettester/TaggingPresetTester.java	(revision 36039)
+++ applications/editors/josm/plugins/tagging-preset-tester/src/org/openstreetmap/josm/plugins/taggingpresettester/TaggingPresetTester.java	(revision 36040)
@@ -54,4 +54,7 @@
         } else {
             x = makeFakeSuitablePrimitive(preset);
+            // See #21829: DataIntegrityProblemException: Primitive must be part of the dataset
+            DataSet tmp = new DataSet();
+            x.forEach(tmp::addPrimitiveRecursive);
         }
         JPanel p = preset.createPanel(x);