Fixed SoftFever#2562: disable extra perimeters over overhangs for spi…

…ral vase

src/libslic3r/PerimeterGenerator.cpp

@@ -1376,7 +1376,7 @@ std::tuple<std::vector<ExtrusionPaths>, Polygons> generate_extra_perimeters_over
 
 void PerimeterGenerator::apply_extra_perimeters(ExPolygons &infill_area)
 {
-    if (this->lower_slices != nullptr && this->config->detect_overhang_wall && this->config->extra_perimeters_on_overhangs &&
+    if (!m_spiral_vase && this->lower_slices != nullptr && this->config->detect_overhang_wall && this->config->extra_perimeters_on_overhangs &&
         this->config->wall_loops > 0 && this->layer_id > this->object_config->raft_layers) {
         // Generate extra perimeters on overhang areas, and cut them to these parts only, to save print time and material
         auto [extra_perimeters, filled_area] = generate_extra_perimeters_over_overhangs(infill_area, this->lower_slices_polygons(),