Two bug fixes in DRC related to flatten:

- Merge semantics wasn't transferred to flat region
- Merge semantics wasn't set at all in deep region

src/db/db/dbRegion.cc

@@ -310,9 +310,8 @@ Region::flat_region ()
   if (! region) {
     region = new FlatRegion ();
     if (mp_delegate) {
+      region->RegionDelegate::operator= (*mp_delegate);   //  copy basic flags
       region->insert_seq (begin ());
-    }
-    if (mp_delegate) {
       region->set_is_merged (mp_delegate->is_merged ());
     }
     set_delegate (region);

src/db/db/gsiDeclDbRegion.cc

@@ -135,7 +135,7 @@ static db::Region *new_si2 (const db::RecursiveShapeIterator &si, const db::ICpl
 
 static db::Region *new_sid2 (const db::RecursiveShapeIterator &si, db::DeepShapeStore &dss, const db::ICplxTrans &trans, double area_ratio, size_t max_vertex_count)
 {
-  return new db::Region (si, dss, trans, area_ratio, max_vertex_count);
+  return new db::Region (si, dss, trans, true, area_ratio, max_vertex_count);
 }
 
 static std::string to_string0 (const db::Region *r)

src/drc/drc/built-in-macros/drc.lym

@@ -1360,7 +1360,7 @@ CODE
     # It is an alias for the "&" operator.
     #
     # This method is available for polygon and edge layers.
-    # If the first operand is an edge layer and the second is an edge layer, the
+    # If the first operand is an edge layer and the second is a polygon layer, the
     # result will be the edges of the first operand which are inside or on the
     # borders of the polygons of the second operand.
     #

testdata/drc/drcSimpleTests_4.drc

@@ -33,18 +33,45 @@ l2.output(2, 0)
 l1_flat.output(11, 0)
 l2_flat.output(12, 0)
 
-l1.and(l2).output(1000, 0)
-l1_flat.and(l2).output(1001, 0)
-l1.and(l2_flat).output(1002, 0)
-l1_flat.and(l2_flat).output(1003, 0)
+r = l1.and(l2)
+r.output(1000, 0)
+r.extents.output(1100, 0)
 
-l1.separation(l2, 0.3).output(1020, 0)
-l1_flat.separation(l2, 0.3).output(1021, 0)
-l1.separation(l2_flat, 0.3).output(1022, 0)
-l1_flat.separation(l2_flat, 0.3).output(1023, 0)
+r = l1_flat.and(l2)
+r.output(1001, 0)
+r.extents.output(1101, 0)
+
+r = l1.and(l2_flat)
+r.output(1002, 0)
+r.extents.output(1102, 0)
+
+r = l1_flat.and(l2_flat)
+r.output(1003, 0)
+r.extents.output(1103, 0)
+
+r = l1.separation(l2, 0.3)
+r.output(1020, 0)
+r.extents.output(1120, 0)
+
+r = l1_flat.separation(l2, 0.3)
+r.output(1021, 0)
+r.extents.output(1121, 0)
+
+r = l1.separation(l2_flat, 0.3)
+r.output(1022, 0)
+r.extents.output(1122, 0)
+
+r = l1_flat.separation(l2_flat, 0.3)
+r.output(1023, 0)
+r.extents.output(1123, 0)
+
+r = l1.space(0.5)
+r.output(1010, 0)
+r.extents.output(1110, 0)
 
-l1.space(0.2).output(1010, 0)
 l1.flatten
-l1.space(0.2).output(1011, 0)
+r = l1.space(0.5)
+r.output(1011, 0)
+r.extents.output(1111, 0)