grt/cugr: return rerouted nets from incremental route to match FastRoute path

Signed-off-by: Eder Monteiro <emrmonteiro@precisioninno.com>

Author: eder-matheus

src/grt/src/GlobalRouter.cpp

@@ -6369,6 +6369,8 @@ std::vector<Net*> GlobalRouter::updateDirtyRoutes(bool save_guides)
 
   if (use_cugr_) {
     cugr_->setVerbose(false);
+    std::vector<Net*> dirty_nets;
+    dirty_nets.reserve(dirty_nets_.size());
     for (odb::dbNet* db_net : dirty_nets_) {
       // Rebuild the GlobalRouter pin set from the netlist (as updateDirtyNets
       // does for FastRoute); updatePinAccessPoints below fixes the positions.
@@ -6377,13 +6379,14 @@ std::vector<Net*> GlobalRouter::updateDirtyRoutes(bool save_guides)
       net->setDirtyNet(false);
       net->clearLastPinPositions();
       cugr_->updateNet(db_net);
+      dirty_nets.push_back(net);
     }
     dirty_nets_.clear();
     cugr_->routeIncremental();
     routes_ = cugr_->getRoutes();
     // Sync pin access points with CUGR's routing, as the full route does.
     updatePinAccessPoints();
-    return {};
+    return dirty_nets;
   }
 
   std::vector<Net*> dirty_nets;