Tweak vertical position of labels under points in "cartographic"

label placement mode

Previously labels were being drawn too low

src/core/qgspallabeling.cpp

@@ -2695,7 +2695,7 @@ void QgsPalLayerSettings::registerFeature( QgsFeature& f, QgsRenderContext &cont
 
   //set label's visual margin so that top visual margin is the leading, and bottom margin is the font's descent
   //this makes labels align to the font's baseline or highest character
-  double topMargin = qMax( labelFontMetrics->leading(), 0.0 ) + 1.0;
+  double topMargin = qMax( 0.25 * labelFontMetrics->ascent(), 0.0 );
   double bottomMargin = 1.0 + labelFontMetrics->descent();
   QgsLabelFeature::VisualMargin vm( topMargin, 0.0, bottomMargin, 0.0 );
   vm *= xform->mapUnitsPerPixel() / rasterCompressFactor;