Applying scale to armature moves objects with bone relationship

Question

I created a simple armature with a couple of bones.

I then scaled my armature (I understand it's better not to do so, but this is something I need for other purposes)

I added 'Arrows' object and parented it to the last bone in my armature.

Which gives me this setup (works perfectly, I can move the bones and my arrows correctly moves together with the last bone).

I then apply scale to the armature, which moves my arrow object to some arbitrary (?) position.

And my object has non zero transforms:

This seems very counterintuitive? And I can't even understand logic behind the position change. It does look like Blender detaches the arrow, does some calculations in global space and attaches it back?

So two questions:

1. Why does this happen?
2. Is there a way to prevent this, so applying the scale would not move the arrow object and it will remain attached to the last bone at (0, 0, 0)

(just in case, I've created this scene from scratch, there are no animations, modifiers or anything extra, blender file)

Answer 1

To be honest, I don't know precisely WHY this happens, but there are two ways to avoid it.

1. Un-parent it, and add the Copy Transforms object constraint. This will keep your object in the correct position both before and after applying the Scale. You can even apply independent Copy Location and Copy Rotation constraints if you don't want the final object's scale to change.

In the viewer, hit Ctrl-A and click 'Visual transforms' at the bottom to apply them if you need to remove the constraints later.

2. Before applying the scale, drag it into a collection in the outliner while holding Shift and Alt. This will re-parent it to the collection and apply the transforms.