diff --git a/src/libslic3r/Config.cpp b/src/libslic3r/Config.cpp
index 7698894054a..59e0d3cfc31 100644
--- a/src/libslic3r/Config.cpp
+++ b/src/libslic3r/Config.cpp
@@ -1,6 +1,7 @@
 #include "Config.hpp"
-#include "Preset.hpp"
+#include "Flow.hpp"
 #include "format.hpp"
+#include "Preset.hpp"
 #include "Utils.hpp"
 #include "LocalesUtils.hpp"
 
@@ -1053,7 +1054,7 @@ double ConfigBase::get_computed_value(const t_config_option_key &opt_key, int ex
         if (raw_opt->type() == coFloatOrPercent) {
             auto cofop = static_cast<const ConfigOptionFloatOrPercent*>(raw_opt);
             if (cofop->value == 0 && boost::ends_with(opt_key, "_extrusion_width")) {
-                return this->get_computed_value("extrusion_width");
+                 return Flow::extrusion_width(opt_key, *this, extruder_id);
             }
             if (!cofop->percent)
                 return cofop->value;
diff --git a/src/libslic3r/GCode/SeamPlacer.cpp b/src/libslic3r/GCode/SeamPlacer.cpp
index 786507a9e94..a94e7d66be5 100644
--- a/src/libslic3r/GCode/SeamPlacer.cpp
+++ b/src/libslic3r/GCode/SeamPlacer.cpp
@@ -747,8 +747,13 @@ void process_perimeter_polylines(const PolylineWithEnd &orig_polyline, float z_c
             }
             std::vector<size_t> viable_points_indices;
             std::vector<size_t> large_angle_points_indices;
-            for (size_t point_idx = longest_patch.first; point_idx != longest_patch.second;
-                    point_idx = next_index(point_idx)) {
+            assert(longest_patch.first >= perimeter.start_index && longest_patch.first <= perimeter.end_index);
+            assert(longest_patch.second >= perimeter.start_index && longest_patch.second <= perimeter.end_index);
+            assert(is_polygon || longest_patch.first <= longest_patch.second);
+            for (size_t point_idx = longest_patch.first;
+                 point_idx       != longest_patch.second;
+                 point_idx        = is_polygon ? next_index(point_idx) : (1 + point_idx)) {
+                size_t viable_points_indices_count = viable_points_indices.size();
                 viable_points_indices.push_back(point_idx);
                 if (std::abs(result.points[point_idx].local_ccw_angle)
                         > SeamPlacer::sharp_angle_snapping_threshold) {