Fixed #909 (Crash on DRC)

src/db/db/dbOriginalLayerRegion.cc

@@ -204,6 +204,16 @@ OriginalLayerRegion::count () const
 
     return n;
 
+  } else if (! iter.layout ()) {
+
+    //  for Shapes-based iterators just use the shape count
+
+    if (iter.shapes ()) {
+      return iter.shapes ()->size (iter.shape_flags () & db::ShapeIterator::Regions);
+    } else {
+      return 0;
+    }
+
   } else {
 
     //  otherwise we can utilize the CellCounter

src/db/unit_tests/dbRegionTests.cc

@@ -2094,3 +2094,16 @@ TEST(issue_277)
   r.set_min_coherence (false);  //  needs to merge again
   EXPECT_EQ (r.sized (1).merged (false, 1).to_string (), "");
 }
+
+TEST(issue_909)
+{
+  db::Shapes s1;
+  s1.insert(db::Box(0, 0, 100, 100));
+  db::Shapes s2;
+  s2.insert(db::Box(0, 0, 200, 300));
+  db::Region r1 = db::Region (db::RecursiveShapeIterator (s1));
+  db::Region r2 = db::Region (db::RecursiveShapeIterator (s2));
+
+  db::Region r = r1 + r2;
+  EXPECT_EQ (r.to_string (), "(0,0;0,100;100,100;100,0);(0,0;0,300;200,300;200,0)");
+}