Fix for bug #17735: vertex color render layer got invalid value

when switching to weight paint mode.

diff --git a/source/blender/blenkernel/intern/DerivedMesh.c b/source/blender/blenkernel/intern/DerivedMesh.c
index d4b17f97ad9191e433d40b5ad46b55adc7f43447..b7f068c936b1ad983f4ccabaef7a1a39e7907158 100644 (file)
--- a/source/blender/blenkernel/intern/DerivedMesh.c
+++ b/source/blender/blenkernel/intern/DerivedMesh.c
@@ -2701,17 +2701,22 @@ static void mesh_build_data(Object *ob, CustomDataMask dataMask)
                if( (G.f & G_WEIGHTPAINT) && ob==obact ) {
                        MCol *wpcol = (MCol*)calc_weightpaint_colors(ob);
                        int layernum = CustomData_number_of_layers(&me->fdata, CD_MCOL);
+                       int prevactive = CustomData_get_active_layer(&me->fdata, CD_MCOL);
+                       int prevrender = CustomData_get_render_layer(&me->fdata, CD_MCOL);
 
                        /* ugly hack here, we temporarily add a new active mcol layer with
                           weightpaint colors in it, that is then duplicated in CDDM_from_mesh */
                        CustomData_add_layer(&me->fdata, CD_MCOL, CD_ASSIGN, wpcol, me->totface);
                        CustomData_set_layer_active(&me->fdata, CD_MCOL, layernum);
+                       CustomData_set_layer_render(&me->fdata, CD_MCOL, layernum);
 
                        mesh_calc_modifiers(ob, NULL, &ob->derivedDeform,
                                            &ob->derivedFinal, 0, 1,
                                            needMapping, dataMask, -1);
 
                        CustomData_free_layer_active(&me->fdata, CD_MCOL, me->totface);
+                       CustomData_set_layer_active(&me->fdata, CD_MCOL, prevactive);
+                       CustomData_set_layer_render(&me->fdata, CD_MCOL, prevrender);
                } else {
                        mesh_calc_modifiers(ob, NULL, &ob->derivedDeform,
                                            &ob->derivedFinal, G.rendering, 1,