#2037 "Attacker must know chained attack" broken

[Santino Labbate]

As far as I can tell, the bitset "Attacker must know chained attack" found in the "Chaining" menu results in the chain never occuring..

So far, here's the type of testing I've done:

I have "Attack X" set to chain to "Attack Y", and the "attacker must know chained attack" bitset enabled for Attack X. The attacker(a hero in my party) does indeed know both Attack X and Attack Y.

I've tried moving Attack Y and Attack X around into different Hero Spell Lists and hiding/unhiding the menu's, and the attack still doesn't chain, so it doesn't seem to be a problem with where the attacks are located on the hero's battle menus.

If I simply disable the "attacker must know chained attack" bitset, the chain always works.

Attack Y also works by itself without the chain from Attack X.

Even if I have Attack X chain to itself with the bitset enabled, it fails to chain.

[TeeEmCee]

Wow, you're right, there's clearly an off-by-one bug in the code. It searched the spell lists for attack Y+1 instead of attack Y, and it's been broken ever since it was implemented. If an attack was added directly to the battle menu instead of being put in a spell list, then that worked correctly.

I've fixed it now. Thanks for the report!

[TeeEmCee]

Also, I notice that the way this bitset works is far from obvious, because it has lots of exceptions. I've updated the documentation for it to read:

• "Attacker must know chained attack" causes the chain to fail if the attacker doesn't have the attack in any of their attack lists as a normal attack (not a counterattack), which means:
  -Enemies must have the attack in the Normal, Desperation or Alone lists. Enemy counter attacks and On-Death Bequest attacks do not count as known.
  -Heroes must have the chained attack in one of their spell lists or in their battle menu (either as their weapon attack or a fixed attack added directly to the menu). Attacks in spell lists which can be learnt (e.g from an item) but haven't been learnt yet don't count. Attacks which are disabled for any other reason (costs, being mute, menu options which are tag-disabled, etc) do count as being known.
  Hero counter attacks do not count.