Bug in the attack/fire code?

[Lincoln Peters]

I have noticed that if firing is dependent on having a material (e.g.
torpedoes), and a unit can fight using regular attack as well as firing,
if it runs out of the material that it uses to fire, and the player
clicks on an enemy to attack, it fires, reducing its supply to -1, at
which point it can't do anything.  Shouldn't it attack normally instead,
or at least refuse to fire before it drops below zero storage?