Pcbnew: convert to lines should take the width of polygons if it can

Fixes: https://gitlab.com/kicad/code/kicad/-/issues/18713

pcbnew/CMakeLists.txt

@@ -109,7 +109,7 @@ set( PCBNEW_DIALOGS
     dialogs/dialog_import_settings.cpp
     dialogs/dialog_import_settings_base.cpp
     dialogs/dialog_imported_layers_base.cpp
-        dialogs/dialog_map_layers.cpp
+    dialogs/dialog_map_layers.cpp
     dialogs/dialog_rule_area_properties.cpp
     dialogs/dialog_rule_area_properties_base.cpp
     dialogs/dialog_layer_selection_base.cpp
@@ -371,7 +371,7 @@ set( PCBNEW_CLASS_SRCS
     tools/drc_tool.cpp
     tools/edit_tool.cpp
     tools/edit_tool_move_fct.cpp
-        tools/pcb_edit_table_tool.cpp
+    tools/pcb_edit_table_tool.cpp
     tools/global_edit_tool.cpp
     tools/group_tool.cpp
     tools/footprint_editor_control.cpp
@@ -385,6 +385,7 @@ set( PCBNEW_CLASS_SRCS
     tools/pcb_tool_base.cpp
     tools/placement_tool.cpp
     tools/pcb_point_editor.cpp
+    tools/pcb_tool_utils.cpp
     tools/position_relative_tool.cpp
     tools/tool_event_utils.cpp
     tools/zone_create_helper.cpp

pcbnew/tools/convert_tool.cpp

@@ -46,6 +46,7 @@
 #include <tools/edit_tool.h>
 #include <tools/pcb_actions.h>
 #include <tools/pcb_selection_tool.h>
+#include <tools/pcb_tool_utils.h>
 #include <trigo.h>
 #include <macros.h>
 #include <zone.h>
@@ -1085,9 +1086,12 @@ int CONVERT_TOOL::CreateLines( const TOOL_EVENT& aEvent )
         if( handleGraphicSeg( item ) )
             continue;
 
+        BOARD_ITEM&      boardItem = static_cast<BOARD_ITEM&>( *item );
         SHAPE_POLY_SET   polySet = getPolySet( item );
         std::vector<SEG> segs    = getSegList( polySet );
 
+        std::optional<int> itemWidth = GetBoardItemWidth( boardItem );
+
         if( aEvent.IsAction( &PCB_ACTIONS::convertToLines ) )
         {
             for( SEG& seg : segs )
@@ -1097,6 +1101,11 @@ int CONVERT_TOOL::CreateLines( const TOOL_EVENT& aEvent )
                 graphic->SetLayer( targetLayer );
                 graphic->SetStart( VECTOR2I( seg.A ) );
                 graphic->SetEnd( VECTOR2I( seg.B ) );
+
+                // The width can exist but be 0 for filled, unstroked shapes
+                if( itemWidth && *itemWidth > 0 )
+                    graphic->SetWidth( *itemWidth );
+
                 commit.Add( graphic );
             }
         }
@@ -1113,6 +1122,10 @@ int CONVERT_TOOL::CreateLines( const TOOL_EVENT& aEvent )
                     graphic->SetLayer( targetLayer );
                     graphic->SetStart( VECTOR2I( seg.A ) );
                     graphic->SetEnd( VECTOR2I( seg.B ) );
+
+                    if( itemWidth )
+                        graphic->SetWidth( *itemWidth );
+
                     commit.Add( graphic );
                 }
             }

pcbnew/tools/pcb_tool_utils.cpp

@@ -0,0 +1,50 @@
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+
+ * Copyright (C) 2024 KiCad Developers, see AUTHORS.txt for contributors.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include "tools/pcb_tool_utils.h"
+
+#include <board.h>
+#include <pcb_shape.h>
+#include <pcb_track.h>
+
+std::optional<int> GetBoardItemWidth( const BOARD_ITEM& aItem )
+{
+    switch( aItem.Type() )
+    {
+    case PCB_SHAPE_T:
+    {
+        const PCB_SHAPE& shape = static_cast<const PCB_SHAPE&>( aItem );
+        return shape.GetWidth();
+    }
+
+    case PCB_TRACE_T:
+    {
+        const PCB_TRACK& track = static_cast<const PCB_TRACK&>( aItem );
+        return track.GetWidth();
+    }
+
+    default: break;
+    }
+
+    return std::nullopt;
+}

pcbnew/tools/pcb_tool_utils.h

@@ -0,0 +1,44 @@
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+
+ * Copyright (C) 2024 KiCad Developers, see AUTHORS.txt for contributors.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+/**
+ * @file pcb_tool_utils.h
+ *
+ * Utility functions that can be shared by PCB tools.
+ * Public-API class operations that are not specific to any one tool.
+ */
+
+#pragma once
+
+#include <optional>
+
+class BOARD_ITEM;
+
+/**
+ * Gets the width of a BOARD_ITEM, for items that have a meaningful width.
+ * (e.g. some graphics, tracks).
+ *
+ * @param aItem The item to get the width of.
+ * @return The width of the item, or std::nullopt if the item has no useful width.
+ */
+std::optional<int> GetBoardItemWidth( const BOARD_ITEM& aItem );