Check if object's size appears to be zero, when loading the model file.

src/libslic3r/Model.cpp

@@ -513,6 +513,22 @@ void Model::convert_from_meters(bool only_small_volumes)
         }
 }
 
+static constexpr const double zero_volume = 0.0000000001;
+
+int Model::removed_objects_with_zero_volume()
+{
+    if (objects.size() == 0)
+        return 0;
+
+    int removed = 0;
+    for (int i = int(objects.size()) - 1; i >= 0; i--)
+        if (objects[i]->get_object_stl_stats().volume < zero_volume) {
+            delete_object(size_t(i));
+            removed++;
+        }
+    return removed;
+}
+
 void Model::adjust_min_z()
 {
     if (objects.empty())