Don't count pins of both De Morgan variants when matching to footprint pads.

(And remove un unused variable from grid settings dialog.)

Fixes https://gitlab.com/kicad/code/kicad/-/issues/15550

eeschema/dialogs/dialog_choose_symbol.cpp

@@ -486,6 +486,10 @@ void DIALOG_CHOOSE_SYMBOL::PopulateFootprintSelector( LIB_ID const& aLibId )
         LIB_FIELD* fp_field = symbol->GetFieldById( FOOTPRINT_FIELD );
         wxString   fp_name = fp_field ? fp_field->GetFullText() : wxString( "" );
 
+        // All units, but only a single De Morgan variant.
+        if( symbol->HasConversion() )
+            symbol->GetPins( temp_pins, 0, 1 );
+        else
             symbol->GetPins( temp_pins );
 
         m_fp_sel_ctrl->FilterByPinCount( temp_pins.size() );

eeschema/lib_symbol.cpp

@@ -1015,7 +1015,7 @@ void LIB_SYMBOL::GetPins( LIB_PINS& aList, int aUnit, int aConvert ) const
         if( aUnit && item.m_unit && ( item.m_unit != aUnit ) )
             continue;
 
-        // Shape filtering:
+        // De Morgan variant filtering:
         if( aConvert && item.m_convert && ( item.m_convert != aConvert ) )
             continue;
 
@@ -1470,6 +1470,7 @@ bool LIB_SYMBOL::HasConversion() const
     return false;
 }
 
+
 int LIB_SYMBOL::GetMaxPinNumber() const
 {
     int                        maxPinNumber = 0;

include/dialogs/dialog_grid_settings.h

@@ -32,8 +32,6 @@ struct GRID;
 
 class DIALOG_GRID_SETTINGS : public DIALOG_GRID_SETTINGS_BASE
 {
-    EDA_DRAW_FRAME* m_parent;
-
 public:
     DIALOG_GRID_SETTINGS( wxWindow* aParent, wxWindow* aEventSource, UNITS_PROVIDER* aProvider,
                           GRID& aGrid );