eeschema: Handle Rebuild for subcomponents

The parents are the only items that live in the RTree, so the rebuild
check needs to recurse into the sub structure to check for selection

Fixes https://gitlab.com/kicad/code/kicad/issues/3858

eeschema/sch_component.cpp

@@ -852,6 +852,18 @@ void SCH_COMPONENT::GetFields( std::vector<SCH_FIELD*>& aVector, bool aVisibleOn
 }
 
 
+std::vector<SCH_FIELD*> SCH_COMPONENT::GetFields()
+{
+    std::vector<SCH_FIELD*> retvec;
+    retvec.reserve( m_Fields.size() );
+
+    for( SCH_FIELD& field : m_Fields )
+        retvec.push_back( &field );
+
+    return retvec;
+}
+
+
 SCH_FIELD* SCH_COMPONENT::AddField( const SCH_FIELD& aField )
 {
     int newNdx = m_Fields.size();

eeschema/sch_component.h

@@ -4,7 +4,7 @@
  * Copyright (C) 2015 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2014 Dick Hollenbeck, dick@softplc.com
  * Copyright (C) 2015 Wayne Stambaugh <stambaughw@gmail.com>
- * Copyright (C) 1992-2019 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2020 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
@@ -374,6 +374,11 @@ public:
      */
     void GetFields( std::vector<SCH_FIELD*>& aVector, bool aVisibleOnly );
 
+    /**
+     * Returns a vector of fields from the component
+     */
+    std::vector<SCH_FIELD*> GetFields();
+
     /**
      * Add a field to the symbol.
      *

eeschema/tools/ee_selection_tool.cpp

@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2019 CERN
- * Copyright (C) 2019 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2019-2020 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
@@ -984,12 +984,27 @@ void EE_SELECTION_TOOL::RebuildSelection()
         for( auto item : m_frame->GetScreen()->Items() )
         {
             // If the field and component are selected, only use the component
-            if( item->IsSelected()
-                    && !( item->Type() == SCH_FIELD_T && item->GetParent()
-                               && item->GetParent()->IsSelected() ) )
+            if( item->IsSelected() )
             {
                 select( item );
             }
+            else
+            {
+                if( item->Type() == SCH_COMPONENT_T )
+                {
+                    for( auto field : static_cast<SCH_COMPONENT*>( item )->GetFields() )
+                        if( field->IsSelected() )
+                            select( field );
+                }
+
+                if( item->Type() == SCH_SHEET_T )
+                {
+                    for( auto pin : static_cast<SCH_SHEET*>( item )->GetPins() )
+                        if( pin->IsSelected() )
+                            select( pin );
+                }
+
+            }
         }
     }