Steps to reproduce:
-Simulate a full ship with modules
If you click “fit all” you get a message you are missing the hull or any of the modules.
-Buy the hull
-Click buy all on the right
-Set the number of item to buy for the hull to zero
The game buys a second hull anyway.
I know it is possible somehow for it to make a “buy all” list for the missing modules/hulls considering your current assets clicking fit all, but i can’t reproduce this behavior. Maybe if you’re inside the hull already. I’m not testing this, lost enough money as it is.