[Bf-blender-cvs] [7254463194d] blender-v2.93-release: Fix T87876: vertex groups missing when mesh is in edit mode

[Jacques Lucke]

Commit: 7254463194d7d6ecd7b2e60fe8a6a19ee59a0d76
Author: Jacques Lucke
Date:   Wed Apr 28 14:57:23 2021 +0200
Branches: blender-v2.93-release
https://developer.blender.org/rB7254463194d7d6ecd7b2e60fe8a6a19ee59a0d76

Fix T87876: vertex groups missing when mesh is in edit mode

Differential Revision: https://developer.blender.org/D11107

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M	source/blender/blenkernel/intern/DerivedMesh.cc

===================================================================

diff --git a/source/blender/blenkernel/intern/DerivedMesh.cc b/source/blender/blenkernel/intern/DerivedMesh.cc
index 9f51ef5292f..c8416ac897e 100644
--- a/source/blender/blenkernel/intern/DerivedMesh.cc
+++ b/source/blender/blenkernel/intern/DerivedMesh.cc
@@ -1603,6 +1603,12 @@ static void editbmesh_calc_modifiers(struct Depsgraph *depsgraph,
   /* This geometry set contains the non-mesh data that might be generated by modifiers. */
   GeometrySet geometry_set_final;
 
+  /* Add the initial mesh component, with a copy of the vertex group names from the object,
+   * since they need to be stored in the geometry set for evaluation. */
+  MeshComponent &initial_mesh_component =
+      geometry_set_final.get_component_for_write<MeshComponent>();
+  initial_mesh_component.copy_vertex_group_names_from_object(*ob);
+
   /* Deformed vertex locations array. Deform only modifier need this type of
    * float array rather than MVert*. Tracked along with mesh_final as an
    * optimization to avoid copying coordinates back and forth if there are