Add safety check for seam_slope_start_height

src/libslic3r/GCode.cpp

@@ -4679,6 +4679,8 @@ std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, dou
             double h = paths.front().height;
             start_slope_ratio = m_config.seam_slope_start_height.value / h;
         }
+        if (start_slope_ratio >= 1)
+            start_slope_ratio = 0.99;
 
         double loop_length = 0.;
         for (const auto & path : paths) {

src/libslic3r/PrintConfig.cpp

@@ -3601,6 +3601,7 @@ def = this->add("filament_loading_speed", coFloats);
     def->tooltip = L("Start height of the scarf.\n"
                      "This amount can be specified in millimeters or as a percentage of the current layer height. The default value for this parameter is 0.");
     def->sidetext = L("mm or %");
+    def->ratio_over = "layer_height";
     def->min = 0;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));