[FEATURE] Fix incorrectly swapper layer_property function min_scale and max_scale values

The values returned were the opposite of what's shown in the GUI.

Marked as feature as reminder to include this project break in the
release notes

Author: nyalldawson

src/core/expression/qgsexpressionfunction.cpp

@@ -3361,9 +3361,9 @@ static QVariant fcnGetLayerProperty( const QVariantList &values, const QgsExpres
   else if ( QString::compare( layerProperty, QStringLiteral( "source" ), Qt::CaseInsensitive ) == 0 )
     return layer->publicSource();
   else if ( QString::compare( layerProperty, QStringLiteral( "min_scale" ), Qt::CaseInsensitive ) == 0 )
-    return layer->maximumScale();
-  else if ( QString::compare( layerProperty, QStringLiteral( "max_scale" ), Qt::CaseInsensitive ) == 0 )
     return layer->minimumScale();
+  else if ( QString::compare( layerProperty, QStringLiteral( "max_scale" ), Qt::CaseInsensitive ) == 0 )
+    return layer->maximumScale();
   else if ( QString::compare( layerProperty, QStringLiteral( "crs" ), Qt::CaseInsensitive ) == 0 )
     return layer->crs().authid();
   else if ( QString::compare( layerProperty, QStringLiteral( "crs_definition" ), Qt::CaseInsensitive ) == 0 )

tests/src/core/testqgsexpression.cpp

@@ -1086,8 +1086,8 @@ class TestQgsExpression: public QObject
       QTest::newRow( "layer_property attribution" ) << QStringLiteral( "layer_property('%1','attribution')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->attribution() );
       QTest::newRow( "layer_property attribution_url" ) << QStringLiteral( "layer_property('%1','attribution_url')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->attributionUrl() );
       QTest::newRow( "layer_property source" ) << QStringLiteral( "layer_property('%1','source')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->publicSource() );
-      QTest::newRow( "layer_property min_scale" ) << QStringLiteral( "layer_property('%1','min_scale')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->maximumScale() );
-      QTest::newRow( "layer_property max_scale" ) << QStringLiteral( "layer_property('%1','max_scale')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->minimumScale() );
+      QTest::newRow( "layer_property min_scale" ) << QStringLiteral( "layer_property('%1','min_scale')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->minimumScale() );
+      QTest::newRow( "layer_property max_scale" ) << QStringLiteral( "layer_property('%1','max_scale')" ).arg( mPointsLayer->name() ) << false << QVariant( mPointsLayer->maximumScale() );
       QTest::newRow( "layer_property crs" ) << QStringLiteral( "layer_property('%1','crs')" ).arg( mPointsLayer->name() ) << false << QVariant( "EPSG:4326" );
       QTest::newRow( "layer_property extent" ) << QStringLiteral( "geom_to_wkt(layer_property('%1','extent'))" ).arg( mPointsLayer->name() ) << false << QVariant( "Polygon ((-118.88888889 22.80020704, -83.33333333 22.80020704, -83.33333333 46.87198068, -118.88888889 46.87198068, -118.88888889 22.80020704))" );
       QTest::newRow( "layer_property type" ) << QStringLiteral( "layer_property('%1','type')" ).arg( mPointsLayer->name() ) << false << QVariant( "Vector" );