Update existing file in registry

Hello,

releasing buggy scripts lastly, I discovered that file update is not possible. Did I miss something important in the Edit plugin tab?

Here is the use case :
Create plugin "Coffee Maker"
Attach plugin source coffeemaker.c
Submit
a big bug slipped inside
Edit plugin "Coffee Maker"
Delete attachment coffeemaker.c
Submit
Edit plugin "Coffee Maker"
Attach plugin source coffeemaker.c with no bugs

I tried to attach the new version directly, but it creates a new attachment coffeemaker.c_0

Eric.