Make sure current sheet gets set when creating BOM.

Fixes https://gitlab.com/kicad/code/kicad/issues/6418

eeschema/netlist_exporters/netlist_exporter_base.h

@@ -111,6 +111,9 @@ protected:
     /// The schematic we're generating a netlist for
     SCHEMATIC*            m_schematic;
 
+    /// The schematic's CurrentSheet when we entered.  Restore on exiting.
+    SCH_SHEET_PATH        m_savedCurrentSheet;
+
     /**
      * Function findNextSymbolAndCreatePinList
      * finds a symbol from the DrawList and builds its pin list in m_sortedSymbolPinList. This
@@ -165,10 +168,12 @@ public:
         m_schematic( aSchematic )
     {
         wxASSERT( aSchematic );
+        m_savedCurrentSheet = m_schematic->CurrentSheet();
     }
 
     virtual ~NETLIST_EXPORTER_BASE()
     {
+        m_schematic->SetCurrentSheet( m_savedCurrentSheet );
     }
 
     /**

eeschema/netlist_exporters/netlist_exporter_xml.cpp

@@ -162,15 +162,8 @@ void NETLIST_EXPORTER_XML::addSymbolFields( XNODE* aNode, SCH_COMPONENT* aSymbol
     }
     else
     {
-        if( m_resolveTextVars )
-            fields.value = aSymbol->GetField( VALUE_FIELD )->GetShownText();
-        else
-            fields.value = aSymbol->GetField( VALUE_FIELD )->GetText();
-
-        if( m_resolveTextVars )
-            fields.footprint = aSymbol->GetField( FOOTPRINT_FIELD )->GetShownText();
-        else
-            fields.footprint = aSymbol->GetField( FOOTPRINT_FIELD )->GetText();
+        fields.value = aSymbol->GetValue( aSheet, m_resolveTextVars );
+        fields.footprint = aSymbol->GetFootprint( aSheet, m_resolveTextVars );
 
         if( m_resolveTextVars )
             fields.datasheet = aSymbol->GetField( DATASHEET_FIELD )->GetShownText();
@@ -235,6 +228,7 @@ XNODE* NETLIST_EXPORTER_XML::makeSymbols( unsigned aCtl )
     for( unsigned ii = 0; ii < sheetList.size(); ii++ )
     {
         SCH_SHEET_PATH sheet = sheetList[ii];
+        m_schematic->SetCurrentSheet( sheet );
 
         auto cmp = [sheet]( SCH_COMPONENT* a, SCH_COMPONENT* b )
                    {
@@ -244,7 +238,7 @@ XNODE* NETLIST_EXPORTER_XML::makeSymbols( unsigned aCtl )
 
         std::set<SCH_COMPONENT*, decltype( cmp )> ordered_symbols( cmp );
 
-        for( SCH_ITEM* item : sheetList[ii].LastScreen()->Items().OfType( SCH_COMPONENT_T ) )
+        for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_COMPONENT_T ) )
         {
             SCH_COMPONENT* symbol = static_cast<SCH_COMPONENT*>( item );
             auto           test = ordered_symbols.insert( symbol );

eeschema/sch_component.cpp

@@ -576,12 +576,9 @@ const wxString SCH_COMPONENT::GetValue( const SCH_SHEET_PATH* sheet, bool aResol
     {
         if( instance.m_Path == path && !instance.m_Value.IsEmpty() )
         {
-            if( !aResolve )
-                return instance.m_Value;
-
-            SCH_FIELD dummy( wxDefaultPosition, VALUE_FIELD, const_cast<SCH_COMPONENT*>( this ) );
-            dummy.SetText( instance.m_Value );
-            return dummy.GetShownText();
+            // This can only be an override from an Update Schematic from PCB, and therefore
+            // will always be fully resolved.
+            return instance.m_Value;
         }
     }
 
@@ -629,12 +626,9 @@ const wxString SCH_COMPONENT::GetFootprint( const SCH_SHEET_PATH* sheet, bool aR
     {
         if( instance.m_Path == path && !instance.m_Footprint.IsEmpty() )
         {
-            if( !aResolve )
-                return instance.m_Footprint;
-
-            SCH_FIELD dummy( wxDefaultPosition, FOOTPRINT_FIELD, const_cast<SCH_COMPONENT*>( this ) );
-            dummy.SetText( instance.m_Footprint );
-            return dummy.GetShownText();
+            // This can only be an override from an Update Schematic from PCB, and therefore
+            // will always be fully resolved.
+            return instance.m_Footprint;
         }
     }