Revert "fix: don't fill perimeter gaps between inner wall and skin/infill (CURA-4027)"

This reverts commit 9432af2.

This fixes CURA-4251

Author: BagelOrb

src/FffPolygonGenerator.cpp

@@ -432,6 +432,10 @@ void FffPolygonGenerator::processPerimeterGaps(SliceDataStorage& storage)
         {
             continue;
         }
+        bool fill_gaps_between_inner_wall_and_skin_or_infill =
+            mesh.getSettingInMicrons("infill_line_distance") > 0
+            && !mesh.getSettingBoolean("infill_hollow")
+            && mesh.getSettingInMicrons("infill_overlap_mm") >= 0;
         for (unsigned int layer_nr = 0; layer_nr < mesh.layers.size(); layer_nr++)
         {
             SliceLayer& layer = mesh.layers[layer_nr];
@@ -458,7 +462,18 @@ void FffPolygonGenerator::processPerimeterGaps(SliceDataStorage& storage)
                 }
 
                 // gap between inner wall and skin/infill
-                // are note handled. There might be gaps due to alternate extra perimeter or due to initial layer line width multiplier
+                if (fill_gaps_between_inner_wall_and_skin_or_infill && part.insets.size() > 0)
+                {
+                    const Polygons outer = part.insets.back().offset(-1 * line_width / 2 - perimeter_gaps_extra_offset);
+
+                    Polygons inner = part.infill_area;
+                    for (const SkinPart& skin_part : part.skin_parts)
+                    {
+                        inner.add(skin_part.outline);
+                    }
+                    inner = inner.unionPolygons();
+                    part.perimeter_gaps.add(outer.difference(inner));
+                }
 
                 // add perimeter gaps for skin insets
                 for (SkinPart& skin_part : part.skin_parts)