How to ideally joint objects
Hi there,
How can I joint the objects corners together flawlessly, without any gaps? I need to have it like this

but with all my trying I can get only this

(both docs are RGB mode)
I made increment as minimum (0,001 px), I tried both with "Snap to point" and without it, I tried to adjust the corners with Direct Selection -- nothing, it's always too big step and therefore it's always this gap between the corners. Why is that?
Thanks !