Fix: missing geometry copy before modifying it

A geometry component may reference read-only geometry.
In this case it has to be copied before making changes to it.

This was caused by rBb876ce2a4a4638142.

4 files changed, 8 insertions, 4 deletions

diff --git a/source/blender/blenkernel/intern/geometry_component_curve.cc b/source/blender/blenkernel/intern/geometry_component_curve.cc
index 0d899ec7b06..22f105af0f1 100644
--- a/source/blender/blenkernel/intern/geometry_component_curve.cc
+++ b/source/blender/blenkernel/intern/geometry_component_curve.cc
@@ -1452,7 +1452,8 @@ std::optional<blender::bke::AttributeAccessor> CurveComponentLegacy::attributes(
 
 std::optional<blender::bke::MutableAttributeAccessor> CurveComponentLegacy::attributes_for_write()
 {
-  return blender::bke::MutableAttributeAccessor(curve_,
+  CurveEval *curve = this->get_for_write();
+  return blender::bke::MutableAttributeAccessor(curve,
                                                 blender::bke::get_curve_accessor_functions_ref());
 }
 
diff --git a/source/blender/blenkernel/intern/geometry_component_curves.cc b/source/blender/blenkernel/intern/geometry_component_curves.cc
index 34c17bedc2c..f803b08e740 100644
--- a/source/blender/blenkernel/intern/geometry_component_curves.cc
+++ b/source/blender/blenkernel/intern/geometry_component_curves.cc
@@ -644,6 +644,7 @@ std::optional<blender::bke::AttributeAccessor> CurveComponent::attributes() cons
 
 std::optional<blender::bke::MutableAttributeAccessor> CurveComponent::attributes_for_write()
 {
-  return blender::bke::MutableAttributeAccessor(curves_ ? &curves_->geometry : nullptr,
+  Curves *curves = this->get_for_write();
+  return blender::bke::MutableAttributeAccessor(curves ? &curves->geometry : nullptr,
                                                 blender::bke::get_curves_accessor_functions_ref());
 }
diff --git a/source/blender/blenkernel/intern/geometry_component_mesh.cc b/source/blender/blenkernel/intern/geometry_component_mesh.cc
index cb36b9b19f7..cf6681a69be 100644
--- a/source/blender/blenkernel/intern/geometry_component_mesh.cc
+++ b/source/blender/blenkernel/intern/geometry_component_mesh.cc
@@ -1324,7 +1324,8 @@ std::optional<blender::bke::AttributeAccessor> MeshComponent::attributes() const
 
 std::optional<blender::bke::MutableAttributeAccessor> MeshComponent::attributes_for_write()
 {
-  return blender::bke::MutableAttributeAccessor(mesh_,
+  Mesh *mesh = this->get_for_write();
+  return blender::bke::MutableAttributeAccessor(mesh,
                                                 blender::bke::get_mesh_accessor_functions_ref());
 }
 
diff --git a/source/blender/blenkernel/intern/geometry_component_pointcloud.cc b/source/blender/blenkernel/intern/geometry_component_pointcloud.cc
index b439a9ba7f8..ccc97f92dbc 100644
--- a/source/blender/blenkernel/intern/geometry_component_pointcloud.cc
+++ b/source/blender/blenkernel/intern/geometry_component_pointcloud.cc
@@ -226,8 +226,9 @@ std::optional<blender::bke::AttributeAccessor> PointCloudComponent::attributes()
 
 std::optional<blender::bke::MutableAttributeAccessor> PointCloudComponent::attributes_for_write()
 {
+  PointCloud *pointcloud = this->get_for_write();
   return blender::bke::MutableAttributeAccessor(
-      pointcloud_, blender::bke::get_pointcloud_accessor_functions_ref());
+      pointcloud, blender::bke::get_pointcloud_accessor_functions_ref());
 }
 
 /** \} */