Implement GetEffectiveShape for groups.

Fixes https://gitlab.com/kicad/code/kicad/issues/12940

include/pcb_group.h

@@ -157,6 +157,10 @@ public:
     ///< @copydoc EDA_ITEM::GetBoundingBox
     const BOX2I GetBoundingBox() const override;
 
+    // @copydoc BOARD_ITEM::GetEffectiveShape
+    std::shared_ptr<SHAPE> GetEffectiveShape( PCB_LAYER_ID aLayer = UNDEFINED_LAYER,
+                                              FLASHING aFlash = FLASHING::DEFAULT ) const override;
+
     ///< @copydoc EDA_ITEM::Visit
     INSPECT_RESULT Visit( INSPECTOR aInspector, void* aTestData,
                           const std::vector<KICAD_T>& aScanTypes ) override;

pcbnew/footprint.h

@@ -750,7 +750,8 @@ public:
      */
     void BuildCourtyardCaches( OUTLINE_ERROR_HANDLER* aErrorHandler = nullptr );
 
-    virtual std::shared_ptr<SHAPE> GetEffectiveShape( PCB_LAYER_ID aLayer = UNDEFINED_LAYER,
+    // @copydoc BOARD_ITEM::GetEffectiveShape
+    std::shared_ptr<SHAPE> GetEffectiveShape( PCB_LAYER_ID aLayer = UNDEFINED_LAYER,
                                               FLASHING aFlash = FLASHING::DEFAULT ) const override;
 
 #if defined(DEBUG)

pcbnew/pcb_group.cpp

@@ -23,6 +23,7 @@
  */
 #include <bitmaps.h>
 #include <eda_draw_frame.h>
+#include <geometry/shape_compound.h>
 #include <board.h>
 #include <board_item.h>
 #include <footprint.h>
@@ -248,6 +249,17 @@ const BOX2I PCB_GROUP::GetBoundingBox() const
 }
 
 
+std::shared_ptr<SHAPE> PCB_GROUP::GetEffectiveShape( PCB_LAYER_ID aLayer, FLASHING aFlash ) const
+{
+    std::shared_ptr<SHAPE_COMPOUND> shape = std::make_shared<SHAPE_COMPOUND>();
+
+    for( BOARD_ITEM* item : m_items )
+        shape->AddShape( item->GetEffectiveShape( aLayer, aFlash )->Clone() );
+
+    return shape;
+}
+
+
 INSPECT_RESULT PCB_GROUP::Visit( INSPECTOR aInspector, void* aTestData,
                                  const std::vector<KICAD_T>& aScanTypes )
 {

pcbnew/pcb_track.h

@@ -152,7 +152,7 @@ public:
                                   bool ignoreLineWidth = false ) const override;
 
     // @copydoc BOARD_ITEM::GetEffectiveShape
-    virtual std::shared_ptr<SHAPE> GetEffectiveShape( PCB_LAYER_ID aLayer = UNDEFINED_LAYER,
+    std::shared_ptr<SHAPE> GetEffectiveShape( PCB_LAYER_ID aLayer = UNDEFINED_LAYER,
                                               FLASHING aFlash = FLASHING::DEFAULT ) const override;
 
     /**
@@ -334,7 +334,7 @@ public:
     }
 
     // @copydoc BOARD_ITEM::GetEffectiveShape
-    virtual std::shared_ptr<SHAPE> GetEffectiveShape( PCB_LAYER_ID aLayer = UNDEFINED_LAYER,
+    std::shared_ptr<SHAPE> GetEffectiveShape( PCB_LAYER_ID aLayer = UNDEFINED_LAYER,
                                               FLASHING aFlash = FLASHING::DEFAULT ) const override;
 
     /**