Handle invalid pads more gracefully

Pads generated outside of KiCad may have self-intersecting polygons that
simplify to multiple sets.  We handle this by adding multiple primitives
for such polygons and limiting our fracture calls to only polygons that
have holes

Fixes https://gitlab.com/kicad/code/kicad/issues/10712

pcbnew/dialogs/dialog_pad_basicshapes_properties.cpp

@@ -246,7 +246,6 @@ DIALOG_PAD_PRIMITIVE_POLY_PROPS::DIALOG_PAD_PRIMITIVE_POLY_PROPS( wxWindow* aPar
     TransferDataToWindow();
 
     m_sdbSizerOK->SetDefault();
-    GetSizer()->SetSizeHints( this );
 
 	m_gridCornersList->Connect( wxEVT_GRID_CELL_CHANGING,
                                 wxGridEventHandler( DIALOG_PAD_PRIMITIVE_POLY_PROPS::onCellChanging ),

pcbnew/dialogs/dialog_pad_properties.cpp

@@ -732,7 +732,7 @@ void DIALOG_PAD_PROPERTIES::displayPrimitivesList()
         case SHAPE_T::POLY:
             bs_info[0] = "Polygon";
             bs_info[1] = wxString::Format( _( "corners count %d" ),
-                                           (int) primitive->GetPolyShape().Outline( 0 ).PointCount() );
+                                           primitive->GetPolyShape().Outline( 0 ).PointCount() );
             break;
 
         default:
@@ -1464,7 +1464,7 @@ void DIALOG_PAD_PROPERTIES::redraw()
 
     while( select >= 0 )
     {
-        PCB_SHAPE* dummyShape = (PCB_SHAPE*) m_primitives[select]->Clone();
+        PCB_SHAPE* dummyShape = static_cast<PCB_SHAPE*>( m_primitives[select]->Clone() );
         dummyShape->SetLayer( SELECTED_ITEMS_LAYER );
         dummyShape->Rotate( wxPoint( 0, 0), m_dummyPad->GetOrientation() );
         dummyShape->Move( m_dummyPad->GetPosition() );

pcbnew/pad_custom_shape_functions.cpp

@@ -42,15 +42,24 @@ void PAD::AddPrimitivePoly( const SHAPE_POLY_SET& aPoly, int aThickness, bool aF
     // If aPoly has holes, convert it to a polygon with no holes.
     SHAPE_POLY_SET poly_no_hole;
     poly_no_hole.Append( aPoly );
-    poly_no_hole.Fracture( SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );
 
-    PCB_SHAPE* item = new PCB_SHAPE();
-    item->SetShape( SHAPE_T::POLY );
-    item->SetFilled( aFilled );
-    item->SetPolyShape( poly_no_hole );
-    item->SetWidth( aThickness );
-    item->SetParent( this );
-    m_editPrimitives.emplace_back( item );
+    if( poly_no_hole.HasHoles() )
+        poly_no_hole.Fracture( SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );
+
+    // There should never be multiple shapes, but if there are, we split them into
+    // primitives so that we can edit them both.
+    for( int ii = 0; ii < poly_no_hole.OutlineCount(); ++ii )
+    {
+        SHAPE_POLY_SET poly_outline( poly_no_hole.COutline( ii ) );
+        PCB_SHAPE* item = new PCB_SHAPE();
+        item->SetShape( SHAPE_T::POLY );
+        item->SetFilled( aFilled );
+        item->SetPolyShape( poly_outline );
+        item->SetWidth( aThickness );
+        item->SetParent( this );
+        m_editPrimitives.emplace_back( item );
+    }
+
     SetDirty();
 }