diff --git a/source/blender/editors/object/object_vgroup.c b/source/blender/editors/object/object_vgroup.c
index 56f59dca9a1..3c406764157 100644
--- a/source/blender/editors/object/object_vgroup.c
+++ b/source/blender/editors/object/object_vgroup.c
@@ -363,8 +363,8 @@ void ED_vgroup_parray_remove_zero(MDeformVert **dvert_array, const int dvert_tot
 /* matching index only */
 bool ED_vgroup_array_copy(Object *ob, Object *ob_from)
 {
-	MDeformVert **dvert_array_from, **dvf;
-	MDeformVert **dvert_array, **dv;
+	MDeformVert **dvert_array_from = NULL, **dvf;
+	MDeformVert **dvert_array = NULL, **dv;
 	int dvert_tot_from;
 	int dvert_tot;
 	int i;
@@ -375,26 +375,30 @@ bool ED_vgroup_array_copy(Object *ob, Object *ob_from)
 	if (ob == ob_from)
 		return true;
 
-	ED_vgroup_parray_alloc(ob_from->data, &dvert_array_from, &dvert_tot_from, false);
-	ED_vgroup_parray_alloc(ob->data, &dvert_array, &dvert_tot, false);
-
-	if ((dvert_array == NULL) && (dvert_array_from != NULL) && BKE_object_defgroup_data_create(ob->data)) {
+	/* in case we copy vgroup between two objects using same data, we only have to care about object side of things. */
+	if (ob->data != ob_from->data) {
+		ED_vgroup_parray_alloc(ob_from->data, &dvert_array_from, &dvert_tot_from, false);
 		ED_vgroup_parray_alloc(ob->data, &dvert_array, &dvert_tot, false);
-		new_vgroup = true;
-	}
 
-	if (dvert_tot == 0 || (dvert_tot != dvert_tot_from) || dvert_array_from == NULL || dvert_array == NULL) {
-
-		if (dvert_array) MEM_freeN(dvert_array);
-		if (dvert_array_from) MEM_freeN(dvert_array_from);
-
-		if (new_vgroup == true) {
-			/* free the newly added vgroup since it wasn't compatible */
-			BKE_object_defgroup_remove_all(ob);
+		if ((dvert_array == NULL) && (dvert_array_from != NULL) && BKE_object_defgroup_data_create(ob->data)) {
+			ED_vgroup_parray_alloc(ob->data, &dvert_array, &dvert_tot, false);
+			new_vgroup = true;
 		}
 
-		/* if true: both are 0 and nothing needs changing, consider this a success */
-		return (dvert_tot == dvert_tot_from);
+		if (dvert_tot == 0 || (dvert_tot != dvert_tot_from) || dvert_array_from == NULL || dvert_array == NULL) {
+			if (dvert_array)
+				MEM_freeN(dvert_array);
+			if (dvert_array_from)
+				MEM_freeN(dvert_array_from);
+
+			if (new_vgroup == true) {
+				/* free the newly added vgroup since it wasn't compatible */
+				BKE_object_defgroup_remove_all(ob);
+			}
+
+			/* if true: both are 0 and nothing needs changing, consider this a success */
+			return (dvert_tot == dvert_tot_from);
+		}
 	}
 
 	/* do the copy */
@@ -412,22 +416,23 @@ bool ED_vgroup_array_copy(Object *ob, Object *ob_from)
 		MEM_freeN(remap);
 	}
 
-	dvf = dvert_array_from;
-	dv = dvert_array;
+	if (dvert_array_from != NULL && dvert_array != NULL) {
+		dvf = dvert_array_from;
+		dv = dvert_array;
 
-	for (i = 0; i < dvert_tot; i++, dvf++, dv++) {
-		if ((*dv)->dw)
-			MEM_freeN((*dv)->dw);
+		for (i = 0; i < dvert_tot; i++, dvf++, dv++) {
+			MEM_SAFE_FREE((*dv)->dw);
+			*(*dv) = *(*dvf);
 
-		*(*dv) = *(*dvf);
+			if ((*dv)->dw) {
+				(*dv)->dw = MEM_dupallocN((*dv)->dw);
+			}
+		}
 
-		if ((*dv)->dw)
-			(*dv)->dw = MEM_dupallocN((*dv)->dw);
+		MEM_freeN(dvert_array);
+		MEM_freeN(dvert_array_from);
 	}
 
-	MEM_freeN(dvert_array);
-	MEM_freeN(dvert_array_from);
-
 	return true;
 }
 
diff --git a/source/blenderplayer/bad_level_call_stubs/stubs.c b/source/blenderplayer/bad_level_call_stubs/stubs.c
index a297dac0f55..08d00e9148a 100644
--- a/source/blenderplayer/bad_level_call_stubs/stubs.c
+++ b/source/blenderplayer/bad_level_call_stubs/stubs.c
@@ -235,13 +235,13 @@ struct RenderLayer *RE_GetRenderLayer(struct RenderResult *rr, const char *name)
 void RE_texture_rng_init() RET_NONE
 void RE_texture_rng_exit() RET_NONE
 
-bool RE_layers_have_name(struct RenderResult *result) {STUB_ASSERT(0); return 0;}
+bool RE_layers_have_name(struct RenderResult *result) RET_ZERO
 const char *RE_engine_active_view_get(struct RenderEngine *engine) RET_NULL
-void RE_engine_active_view_set(struct RenderEngine *engine, const char *viewname) {STUB_ASSERT(0);}
-void RE_engine_get_camera_model_matrix(struct RenderEngine *engine, struct Object *camera, int use_spherical_stereo, float *r_modelmat) {STUB_ASSERT(0);}
+void RE_engine_active_view_set(struct RenderEngine *engine, const char *viewname) RET_NONE
+void RE_engine_get_camera_model_matrix(struct RenderEngine *engine, struct Object *camera, int use_spherical_stereo, float *r_modelmat) RET_NONE
 float RE_engine_get_camera_shift_x(struct RenderEngine *engine, struct Object *camera, int use_spherical_stereo) RET_ZERO
 int RE_engine_get_spherical_stereo(struct RenderEngine *engine, struct Object *camera) RET_ZERO
-void RE_SetActiveRenderView(struct Render *re, const char *viewname) {STUB_ASSERT(0);}
+void RE_SetActiveRenderView(struct Render *re, const char *viewname) RET_NONE
 
 struct RenderPass *RE_pass_find_by_type(volatile struct RenderLayer *rl, int passtype, const char *viewname) RET_NULL
 bool RE_HasFakeLayer(RenderResult *res) RET_ZERO
@@ -460,17 +460,17 @@ void ED_node_texture_default(const struct bContext *C, struct Tex *tex) RET_NONE
 void ED_node_tag_update_id(struct ID *id) RET_NONE
 void ED_node_tag_update_nodetree(struct Main *bmain, struct bNodeTree *ntree, struct bNode *node) RET_NONE
 void ED_node_tree_update(const struct bContext *C) RET_NONE
-void ED_node_set_tree_type(struct SpaceNode *snode, struct bNodeTreeType *typeinfo){}
-void ED_init_custom_node_type(struct bNodeType *ntype){}
-void ED_init_custom_node_socket_type(struct bNodeSocketType *stype){}
+void ED_node_set_tree_type(struct SpaceNode *snode, struct bNodeTreeType *typeinfo) RET_NONE
+void ED_init_custom_node_type(struct bNodeType *ntype) RET_NONE
+void ED_init_custom_node_socket_type(struct bNodeSocketType *stype) RET_NONE
 void ED_init_standard_node_socket_type(struct bNodeSocketType *stype) RET_NONE
 void ED_init_node_socket_type_virtual(struct bNodeSocketType *stype) RET_NONE
-int ED_node_tree_path_length(struct SpaceNode *snode){return 0;}
-void ED_node_tree_path_get(struct SpaceNode *snode, char *value){}
-void ED_node_tree_path_get_fixedbuf(struct SpaceNode *snode, char *value, int max_length){}
-void ED_node_tree_start(struct SpaceNode *snode, struct bNodeTree *ntree, struct ID *id, struct ID *from){}
-void ED_node_tree_push(struct SpaceNode *snode, struct bNodeTree *ntree, struct bNode *gnode){}
-void ED_node_tree_pop(struct SpaceNode *snode){}
+int ED_node_tree_path_length(struct SpaceNode *snode) RET_ZERO
+void ED_node_tree_path_get(struct SpaceNode *snode, char *value) RET_NONE
+void ED_node_tree_path_get_fixedbuf(struct SpaceNode *snode, char *value, int max_length) RET_NONE
+void ED_node_tree_start(struct SpaceNode *snode, struct bNodeTree *ntree, struct ID *id, struct ID *from) RET_NONE
+void ED_node_tree_push(struct SpaceNode *snode, struct bNodeTree *ntree, struct bNode *gnode) RET_NONE
+void ED_node_tree_pop(struct SpaceNode *snode) RET_NONE
 int ED_view3d_scene_layer_set(int lay, const int *values, int *active) RET_ZERO
 void ED_view3d_quadview_update(struct ScrArea *sa, struct ARegion *ar, bool do_clip) RET_NONE
 void ED_view3d_from_m4(float mat[4][4], float ofs[3], float quat[4], float *dist) RET_NONE
@@ -668,9 +668,9 @@ struct RenderEngine *RE_engine_create(struct RenderEngineType *type) RET_NULL
 void RE_engine_frame_set(struct RenderEngine *engine, int frame, float subframe) RET_NONE
 void RE_FreePersistentData(void) RET_NONE
 void RE_point_density_cache(struct Scene *scene, struct PointDensity *pd, const bool use_render_params) RET_NONE
-void RE_point_density_minmax(struct Scene *scene, struct PointDensity *pd, const bool use_render_params, float r_min[3], float r_max[3]) RET_NONE;
-void RE_point_density_sample(struct Scene *scene, struct PointDensity *pd, int resolution, const bool use_render_params, float *values) RET_NONE;
-void RE_point_density_free(struct PointDensity *pd) RET_NONE;
+void RE_point_density_minmax(struct Scene *scene, struct PointDensity *pd, const bool use_render_params, float r_min[3], float r_max[3]) RET_NONE
+void RE_point_density_sample(struct Scene *scene, struct PointDensity *pd, int resolution, const bool use_render_params, float *values) RET_NONE
+void RE_point_density_free(struct PointDensity *pd) RET_NONE
 void RE_instance_get_particle_info(struct ObjectInstanceRen *obi, float *index, float *age, float *lifetime, float co[3], float *size, float vel[3], float angvel[3]) RET_NONE
 void RE_FreeAllPersistentData(void) RET_NONE
 float RE_fresnel_dielectric(float incoming[3], float normal[3], float eta) RET_ZERO
@@ -752,7 +752,7 @@ void BPY_pyconstraint_exec(struct bPythonConstraint *con, struct bConstraintOb *
 void macro_wrapper(struct wmOperatorType *ot, void *userdata) RET_NONE
 bool pyrna_id_FromPyObject(struct PyObject *obj, struct ID **id) RET_ZERO
 struct PyObject *pyrna_id_CreatePyObject(struct ID *id) RET_NULL
-void BPY_context_update(struct bContext *C) RET_NONE;
+void BPY_context_update(struct bContext *C) RET_NONE
 const char *BPY_app_translations_py_pgettext(const char *msgctxt, const char *msgid) RET_ARG(msgid)
 
 /* intern/dualcon */