Fix failing test + build warning

Author: nyalldawson

src/core/qgsexpression.cpp

@@ -3723,7 +3723,7 @@ static QVariant fcnMapAVals( const QVariantList& values, const QgsExpressionCont
   return getMapValue( values.at( 0 ), parent ).values();
 }
 
-static QVariant fcnEnvVar( const QVariantList& values, const QgsExpressionContext*, QgsExpression* parent )
+static QVariant fcnEnvVar( const QVariantList& values, const QgsExpressionContext*, QgsExpression* )
 {
   QString envVarName = values.at( 0 ).toString();
   return QProcessEnvironment::systemEnvironment().value( envVarName );

src/core/qgspropertycollection.cpp

@@ -109,6 +109,7 @@ QgsPropertyCollection::QgsPropertyCollection( const QgsPropertyCollection& other
 
 QgsPropertyCollection&QgsPropertyCollection::operator=( const QgsPropertyCollection & other )
 {
+  QgsAbstractPropertyCollection::operator=( other );
   mProperties = other.mProperties;
   mProperties.detach();
   mDirty = other.mDirty;