Ticket #10770: 10770-2.patch

src/org/openstreetmap/josm/io/GeoJSONWriter.java

@@ -67 +67 @@
         try (JsonWriter writer = Json.createWriterFactory(config).createWriter(stringWriter)) {
             JsonObjectBuilder object = Json.createObjectBuilder()
                     .add("type", "FeatureCollection")
-                    .add("crs", Json.createObjectBuilder().add("type", "name").add("name", projection.toCode()))
+                    .add("crs", Json.createObjectBuilder().add("type", "name")
+                            .add("properties", Json.createObjectBuilder().add("name", projection.toCode())))
                     .add("generator", "JOSM");
             appendLayerBounds(layer.data, object);
             appendLayerFeatures(layer.data, object);