Alternate fix for T50899

object_get_derived_final shouldn't have been assuming mesh objects.

It's even valid to use a curve as a target for a shrink-wrap modifier.

2 files changed, 9 insertions, 13 deletions

diff --git a/source/blender/blenkernel/intern/DerivedMesh.c b/source/blender/blenkernel/intern/DerivedMesh.c
index 160adcc3988..8b7329cf940 100644
--- a/source/blender/blenkernel/intern/DerivedMesh.c
+++ b/source/blender/blenkernel/intern/DerivedMesh.c
@@ -2912,9 +2912,6 @@ DerivedMesh *editbmesh_get_derived_base(Object *obedit, BMEditMesh *em, CustomDa
 /* get derived mesh from an object, using editbmesh if available. */
 DerivedMesh *object_get_derived_final(Object *ob, const bool for_render)
 {
-	Mesh *me = ob->data;
-	BMEditMesh *em = me->edit_btmesh;
-
 	if (for_render) {
 		/* TODO(sergey): use proper derived render here in the future. */
 		return ob->derivedFinal;
@@ -2922,9 +2919,13 @@ DerivedMesh *object_get_derived_final(Object *ob, const bool for_render)
 
 	/* only return the editmesh if its from this object because
 	 * we don't a mesh from another object's modifier stack: T43122 */
-	if (em && (em->ob == ob)) {
-		DerivedMesh *dm = em->derivedFinal;
-		return dm;
+	if (ob->type == OB_MESH) {
+		Mesh *me = ob->data;
+		BMEditMesh *em = me->edit_btmesh;
+		if (em && (em->ob == ob)) {
+			DerivedMesh *dm = em->derivedFinal;
+			return dm;
+		}
 	}
 
 	return ob->derivedFinal;
diff --git a/source/blender/blenkernel/intern/shrinkwrap.c b/source/blender/blenkernel/intern/shrinkwrap.c
index b14ed2d67ad..7094d5a3547 100644
--- a/source/blender/blenkernel/intern/shrinkwrap.c
+++ b/source/blender/blenkernel/intern/shrinkwrap.c
@@ -588,13 +588,8 @@ void shrinkwrapModifier_deform(ShrinkwrapModifierData *smd, Object *ob, DerivedM
 	DerivedMesh *ss_mesh    = NULL;
 	ShrinkwrapCalcData calc = NULL_ShrinkwrapCalcData;
 
-	/* remove loop dependencies on derived meshes (TODO should this be done elsewhere?)
-	 * This also ensure the target is of type OBJ_MESH avoiding crash in `object_get_derived_final` (see T50899). */
-	if (smd->target) {
-		if (smd->target->type != OB_MESH || smd->target == ob) {
-			smd->target = NULL;
-		}
-	}
+	/* remove loop dependencies on derived meshes (TODO should this be done elsewhere?) */
+	if (smd->target == ob) smd->target = NULL;
 	if (smd->auxTarget == ob) smd->auxTarget = NULL;