[Bf-blender-cvs] [baee000001f] master: Fix T90798: calc_loop_triangles is not updated after joining objects

[Campbell Barton]

Commit: baee000001f6a840f7aa15ad3834afc6639ef0f2
Author: Campbell Barton
Date:   Wed Sep 1 21:44:32 2021 +1000
Branches: master
https://developer.blender.org/rBbaee000001f6a840f7aa15ad3834afc6639ef0f2

Fix T90798: calc_loop_triangles is not updated after joining objects

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M	source/blender/editors/mesh/meshtools.c

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diff --git a/source/blender/editors/mesh/meshtools.c b/source/blender/editors/mesh/meshtools.c
index 27fb21e1dfb..1b720f2c14d 100644
--- a/source/blender/editors/mesh/meshtools.c
+++ b/source/blender/editors/mesh/meshtools.c
@@ -424,6 +424,11 @@ int ED_mesh_join_objects_exec(bContext *C, wmOperator *op)
   /* remove tessface to ensure we don't hold references to invalid faces */
   BKE_mesh_tessface_clear(me);
 
+  /* Clear any run-time data.
+   * Even though this mesh wont typically have run-time data, the Python API can for e.g.
+   * create loop-triangle cache here, which is confusing when left in the mesh, see: T90798. */
+  BKE_mesh_runtime_clear_geometry(me);
+
   /* new material indices and material array */
   if (totmat) {
     matar = MEM_callocN(sizeof(*matar) * totmat, "join_mesh matar");