[Bf-blender-cvs] [19e1b5c1fd6] master: Fix T90972: Crash calling Mesh.clear_geometry in edit-mode

[Campbell Barton]

Commit: 19e1b5c1fd61b622382c2cf7d782e99f6cb8c64b
Author: Campbell Barton
Date:   Thu Sep 2 15:29:36 2021 +1000
Branches: master
https://developer.blender.org/rB19e1b5c1fd61b622382c2cf7d782e99f6cb8c64b

Fix T90972: Crash calling Mesh.clear_geometry in edit-mode

No longer free the edit-mesh pointer while in edit-mode since this
isn't reliable to keep the object in edit-mode while freeing it's
edit-mesh data.

Users who want to exit edit-mode should do so explicitly.

Caused by 6d2f9b1dfa98502e9e9f1a73e3dded2ded1f1ce6.

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

M	source/blender/blenkernel/intern/mesh.c

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

diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index daff82802f9..6814083817c 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -886,6 +886,18 @@ void BKE_mesh_free_data_for_undo(Mesh *me)
   mesh_free_data(&me->id);
 }
 
+/**
+ * \note on data that this function intentionally doesn't free:
+ *
+ * - Materials and shape keys are not freed here (#Mesh.mat & #Mesh.key).
+ *   As freeing shape keys requires tagging the depsgraph for updated relations,
+ *   which is expensive.
+ *   Material slots should be kept in sync with the object.
+ *
+ * - Edit-Mesh (#Mesh.edit_mesh)
+ *   Since edit-mesh is tied to the objects mode,
+ *   which crashes when called in edit-mode, see: T90972.
+ */
 static void mesh_clear_geometry(Mesh *mesh)
 {
   CustomData_free(&mesh->vdata, mesh->totvert);
@@ -895,11 +907,6 @@ static void mesh_clear_geometry(Mesh *mesh)
   CustomData_free(&mesh->pdata, mesh->totpoly);
 
   MEM_SAFE_FREE(mesh->mselect);
-  MEM_SAFE_FREE(mesh->edit_mesh);
-
-  /* Note that materials and shape keys are not freed here. This is intentional, as freeing
-   * shape keys requires tagging the depsgraph for updated relations, which is expensive.
-   * Material slots should be kept in sync with the object. */
 
   mesh->totvert = 0;
   mesh->totedge = 0;