Depsgraph: fix hard CTD on dependency cycles through POSE_INIT.

As reported in T63582, it can cause chan_array to be not ready.
To reliably avoid crashing, the only easy way seems to be to
create the index during COW -- maybe @sergey has a better idea.

1 files changed, 6 insertions, 4 deletions

diff --git a/source/blender/blenkernel/intern/armature_update.c b/source/blender/blenkernel/intern/armature_update.c
index 790f5cb2b31..892b2211bf9 100644
--- a/source/blender/blenkernel/intern/armature_update.c
+++ b/source/blender/blenkernel/intern/armature_update.c
@@ -556,8 +556,9 @@ void BKE_splineik_execute_tree(
 
 /* *************** Depsgraph evaluation callbacks ************ */
 
-static void pose_pchan_index_create(bPose *pose)
+void BKE_pose_pchan_index_rebuild(bPose *pose)
 {
+	MEM_SAFE_FREE(pose->chan_array);
 	const int num_channels = BLI_listbase_count(&pose->chanbase);
 	pose->chan_array = MEM_malloc_arrayN(
 	        num_channels, sizeof(bPoseChannel *), "pose->chan_array");
@@ -605,7 +606,8 @@ void BKE_pose_eval_init(struct Depsgraph *depsgraph,
 		}
 	}
 
-	pose_pchan_index_create(pose);
+	BLI_assert(pose->chan_array != NULL || BLI_listbase_is_empty(&pose->chanbase));
+
 	BKE_armature_cached_bbone_deformation_free_data(object);
 }
 
@@ -806,7 +808,6 @@ static void pose_eval_cleanup_common(Object *object)
 	bPose *pose = object->pose;
 	BLI_assert(pose != NULL);
 	BLI_assert(pose->chan_array != NULL || BLI_listbase_is_empty(&pose->chanbase));
-	MEM_SAFE_FREE(pose->chan_array);
 }
 
 void BKE_pose_eval_done(struct Depsgraph *depsgraph, Object *object)
@@ -839,7 +840,8 @@ void BKE_pose_eval_proxy_init(struct Depsgraph *depsgraph, Object *object)
 	BLI_assert(ID_IS_LINKED(object) && object->proxy_from != NULL);
 	DEG_debug_print_eval(depsgraph, __func__, object->id.name, object);
 
-	pose_pchan_index_create(object->pose);
+	BLI_assert(pose->chan_array != NULL || BLI_listbase_is_empty(&pose->chanbase));
+
 	BKE_armature_cached_bbone_deformation_free_data(object);
 }