Don't test if a reference is null, this cannot happen.

Testing for null references is unnecessary and just results in clang warnings.

Closes #17016.

src/propgrid/advprops.cpp

@@ -947,10 +947,7 @@ wxSystemColourProperty::wxSystemColourProperty( const wxString& label, const wxS
                       gs_cp_es_syscolour_values,
                       &gs_wxSystemColourProperty_choicesCache )
 {
-    if ( &value )
         Init( value.m_type, value.m_colour );
-    else
-        Init( wxPG_COLOUR_CUSTOM, *wxWHITE );
 }
 
 
@@ -959,10 +956,7 @@ wxSystemColourProperty::wxSystemColourProperty( const wxString& label, const wxS
     const wxColourPropertyValue& value )
     : wxEnumProperty( label, name, labels, values, choicesCache )
 {
-    if ( &value )
         Init( value.m_type, value.m_colour );
-    else
-        Init( wxPG_COLOUR_CUSTOM, *wxWHITE );
 }
 
 
@@ -971,10 +965,7 @@ wxSystemColourProperty::wxSystemColourProperty( const wxString& label, const wxS
     const wxColour& value )
     : wxEnumProperty( label, name, labels, values, choicesCache )
 {
-    if ( &value )
         Init( wxPG_COLOUR_CUSTOM, value );
-    else
-        Init( wxPG_COLOUR_CUSTOM, *wxWHITE );
 }
 
 
@@ -2063,7 +2054,7 @@ wxArrayInt wxMultiChoiceProperty::GetValueAsIndices() const
     // Translate values to string indices.
     wxArrayInt selections;
 
-    if ( !m_choices.IsOk() || !m_choices.GetCount() || !(&valueArr) )
+    if ( !m_choices.IsOk() || !m_choices.GetCount() )
     {
         for ( i=0; i<valueArr.size(); i++ )
             selections.Add(-1);