Bugfix: Region#flatten and Edges#flatten did not update the merged cache to flat and Region#flatten did not produce PolygonRefs

src/db/db/dbDeepEdges.cc

@@ -273,24 +273,33 @@ void DeepEdges::reserve (size_t)
   //  Not implemented for deep regions
 }
 
-void DeepEdges::flatten ()
+static
+void flatten_layer (db::DeepLayer &deep_layer)
 {
-  db::Layout &layout = deep_layer ().layout ();
+  db::Layout &layout = deep_layer.layout ();
   if (layout.begin_top_down () != layout.end_top_down ()) {
 
     db::Cell &top_cell = layout.cell (*layout.begin_top_down ());
 
     db::Shapes flat_shapes (layout.is_editable ());
-    for (db::RecursiveShapeIterator iter (layout, top_cell, deep_layer ().layer ()); !iter.at_end (); ++iter) {
+    for (db::RecursiveShapeIterator iter (layout, top_cell, deep_layer.layer ()); !iter.at_end (); ++iter) {
       flat_shapes.insert (iter->edge ().transformed (iter.trans ()));
     }
 
-    layout.clear_layer (deep_layer ().layer ());
+    layout.clear_layer (deep_layer.layer ());
-    top_cell.shapes (deep_layer ().layer ()).swap (flat_shapes);
+    top_cell.shapes (deep_layer.layer ()).swap (flat_shapes);
 
   }
 }
 
+void DeepEdges::flatten ()
+{
+  flatten_layer (deep_layer ());
+  if (m_merged_edges_valid) {
+    flatten_layer (const_cast<db::DeepLayer &> (merged_deep_layer ()));
+  }
+}
+
 EdgesIteratorDelegate *
 DeepEdges::begin () const
 {

src/db/db/dbDeepRegion.cc

@@ -284,26 +284,37 @@ void DeepRegion::reserve (size_t)
   //  Not implemented for deep regions
 }
 
-void DeepRegion::flatten ()
+static void
+flatten_layer (db::DeepLayer &deep_layer)
 {
-  db::Layout &layout = deep_layer ().layout ();
+  db::Layout &layout = deep_layer.layout ();
   if (layout.begin_top_down () != layout.end_top_down ()) {
 
     db::Cell &top_cell = layout.cell (*layout.begin_top_down ());
 
     db::Shapes flat_shapes (layout.is_editable ());
-    for (db::RecursiveShapeIterator iter (layout, top_cell, deep_layer ().layer ()); !iter.at_end (); ++iter) {
+    for (db::RecursiveShapeIterator iter (layout, top_cell, deep_layer.layer ()); !iter.at_end (); ++iter) {
+      if (iter->is_polygon ()) {
         db::Polygon poly;
         iter->polygon (poly);
-      flat_shapes.insert (poly.transformed (iter.trans ()));
+        flat_shapes.insert (db::PolygonRef (poly.transformed (iter.trans ()), layout.shape_repository ()));
+      }
     }
 
-    layout.clear_layer (deep_layer ().layer ());
+    layout.clear_layer (deep_layer.layer ());
-    top_cell.shapes (deep_layer ().layer ()).swap (flat_shapes);
+    top_cell.shapes (deep_layer.layer ()).swap (flat_shapes);
 
   }
 }
 
+void DeepRegion::flatten ()
+{
+  flatten_layer (deep_layer ());
+  if (m_merged_polygons_valid) {
+    flatten_layer (const_cast<db::DeepLayer &> (merged_deep_layer ()));
+  }
+}
+
 RegionIteratorDelegate *
 DeepRegion::begin () const
 {

testdata/drc/drcSimpleTests_4.drc

@@ -85,6 +85,6 @@ expect_count(l1, 15, 15, "l1 after flatten")
 r = l1.space(0.5)
 r.output(1011, 0)
 r.extents.output(1111, 0)
-expect_count(r, 3, 1, "r on l1.flatten")
+expect_count(r, 3, 3, "r on l1.flatten")