Eeschema: void CollectOtherUnits(): do not try to collect others units

of a not annotated component.

Fixes #4142
https://gitlab.com/kicad/code/kicad/issues/4142

eeschema/dialogs/dialog_edit_one_field.cpp

@@ -273,10 +273,11 @@ void DIALOG_SCH_EDIT_ONE_FIELD::UpdateField( SCH_FIELD* aField, SCH_SHEET_PATH*
 
     // The value, footprint and datasheet fields should be kept in sync in multi-unit
     // parts.
+    // Of course the component must be annotated to collect other units.
     if( editFrame && parent && parent->Type() == SCH_COMPONENT_T
             && ( fieldType == VALUE || fieldType == FOOTPRINT || fieldType == DATASHEET ) )
     {
-        SCH_COMPONENT*              thisUnit = static_cast<SCH_COMPONENT*>( parent );
+        SCH_COMPONENT* thisUnit = static_cast<SCH_COMPONENT*>( parent );
         std::vector<SCH_COMPONENT*> otherUnits;
 
         CollectOtherUnits( editFrame->GetCurrentSheet(), thisUnit, &otherUnits );

eeschema/ee_collectors.cpp

@@ -171,7 +171,8 @@ bool EE_COLLECTOR::IsDraggableJunction() const
 void CollectOtherUnits( SCH_SHEET_PATH& aSheet, SCH_COMPONENT* aUnit,
                         std::vector<SCH_COMPONENT*>* otherUnits )
 {
-    if( aUnit->GetUnitCount() > 1 )
+    // Obviously, one can collect other units only if aUnit is annotated.
+    if( aUnit->GetUnitCount() > 1 && aUnit->IsAnnotated( &aSheet ) )
     {
         const LIB_ID   thisLibId = aUnit->GetLibId();
         const wxString thisRef   = aUnit->GetRef( &aSheet );