diff --git a/testdata/ruby/rdbTest.rb b/testdata/ruby/rdbTest.rb
index 3f436162e..cfb8f0177 100644
--- a/testdata/ruby/rdbTest.rb
+++ b/testdata/ruby/rdbTest.rb
@@ -813,6 +813,18 @@ class RDB_TestClass < TestBase
     rdb.each_cell { |c| cn << c.to_s_items }
     assert_equal(cn.join(";"), "TOP[polygon: (0,0.001;0,0.03;0.02,0.03;0.02,0.001),polygon: (0.01,0.021;0.01,0.051;0.031,0.051;0.031,0.021),polygon: (0.021,0.042;0.021,0.073;0.043,0.073;0.043,0.042)]")
 
+    rdb = RBA::ReportDatabase.new("neu")
+    cat = rdb.create_category("l1")
+    r = RBA::Region::new(c1.begin_shapes_rec(l1)).merged
+    cat.scan_region(rdb.create_cell("TOP"), RBA::CplxTrans::new(0.001), r, true)  # flat scan
+    assert_equal(cat.num_items, 1)
+    cn = []
+    rdb.each_cell { |c| cn << c.to_s_test }
+    assert_equal(cn.join(";"), "TOP[]")
+    cn = []
+    rdb.each_cell { |c| cn << c.to_s_items }
+    assert_equal(cn.join(";"), "TOP[polygon: (0,0.001;0,0.03;0.01,0.03;0.01,0.051;0.021,0.051;0.021,0.073;0.043,0.073;0.043,0.042;0.031,0.042;0.031,0.021;0.02,0.021;0.02,0.001)]")
+
   end
 
   # shape insertion from shape, shapes, recursive iterator