Fix #36391: removing an armature with a custom bone shape object would not

decrement the object user count when removing the armature. This could cause
the object to stick when it shouldn't, in particular when that object is part
of a group.

source/blender/blenkernel/intern/action.c

@@ -616,6 +616,10 @@ void BKE_pose_channels_hash_free(bPose *pose)
 
 void BKE_pose_channel_free(bPoseChannel *pchan)
 {
+	if (pchan->custom) {
+		id_us_min(&pchan->custom->id);
+		pchan->custom = NULL;
+	}
 
 	if (pchan->mpath) {
 		animviz_free_motionpath(pchan->mpath);