Only sketch pads on fab layers if they exist on that side

Fixes https://gitlab.com/kicad/code/kicad/-/issues/4546

pcbnew/dialogs/dialog_plot_base.cpp

@@ -98,7 +98,7 @@ DIALOG_PLOT_BASE::DIALOG_PLOT_BASE( wxWindow* parent, wxWindowID id, const wxStr
 	gbSizer1->Add( m_excludeEdgeLayerOpt, wxGBPosition( 4, 0 ), wxGBSpan( 1, 1 ), wxALIGN_CENTER_VERTICAL, 5 );
 
 	m_sketchPadsOnFabLayers = new wxCheckBox( sbOptionsSizer->GetStaticBox(), ID_ALLOW_PRINT_PAD_ON_SILKSCREEN, _("Sketch pads on fab layers"), wxDefaultPosition, wxDefaultSize, 0 );
-	m_sketchPadsOnFabLayers->SetToolTip( _("Do not plot pads on silkscreen layers, even when they are assigned to them.\nUncheck this if you wish to create assembly drawings from silkscreen layers.") );
+	m_sketchPadsOnFabLayers->SetToolTip( _("Include pad outlines on F.Fab and B.Fab layers when plotting") );
 
 	gbSizer1->Add( m_sketchPadsOnFabLayers, wxGBPosition( 5, 0 ), wxGBSpan( 1, 1 ), wxALIGN_CENTER_VERTICAL, 5 );
 

pcbnew/dialogs/dialog_plot_base.fbp

@@ -920,7 +920,7 @@
                                                         <property name="style"></property>
                                                         <property name="subclass"></property>
                                                         <property name="toolbar_pane">0</property>
-                                                        <property name="tooltip">Do not plot pads on silkscreen layers, even when they are assigned to them.&#x0A;Uncheck this if you wish to create assembly drawings from silkscreen layers.</property>
+                                                        <property name="tooltip">Include pad outlines on F.Fab and B.Fab layers when plotting</property>
                                                         <property name="validator_data_type"></property>
                                                         <property name="validator_style">wxFILTER_NONE</property>
                                                         <property name="validator_type">wxDefaultValidator</property>

pcbnew/plot_board_layers.cpp

@@ -215,8 +215,9 @@ void PlotStandardLayer( BOARD *aBoard, PLOTTER* aPlotter,
     bool onCopperLayer = ( LSET::AllCuMask() & aLayerMask ).any();
     bool onSolderMaskLayer = ( LSET( 2, F_Mask, B_Mask ) & aLayerMask ).any();
     bool onSolderPasteLayer = ( LSET( 2, F_Paste, B_Paste ) & aLayerMask ).any();
-    bool onFabLayer = ( LSET( 2, F_Fab, B_Fab ) & aLayerMask ).any();
-    bool sketchPads = onFabLayer && aPlotOpt.GetSketchPadsOnFabLayers();
+    bool onFrontFab = ( LSET(  F_Fab ) & aLayerMask ).any();
+    bool onBackFab  = ( LSET( B_Fab ) & aLayerMask ).any();
+    bool sketchPads = ( onFrontFab || onBackFab ) && aPlotOpt.GetSketchPadsOnFabLayers();
 
      // Plot edge layer and graphic items
     itemplotter.PlotBoardGraphicItems();
@@ -240,7 +241,9 @@ void PlotStandardLayer( BOARD *aBoard, PLOTTER* aPlotter,
 
             if( !( pad->GetLayerSet() & aLayerMask ).any() )
             {
-                if( sketchPads )
+                if( sketchPads &&
+                        ( ( onFrontFab && pad->GetLayerSet().Contains( F_Cu ) ) ||
+                          ( onBackFab && pad->GetLayerSet().Contains( B_Cu ) ) ) )
                     padPlotMode = SKETCH;
                 else
                     continue;