Collectible Card Game Headquarters

Describe the Bug:
1- Eliminate the Competition if you cancel the spell before you select targets, it goes to graveyard instead of canceling whole spell.
2- Eliminate the Competition if you cancel when prompt to select creature to sacrifice (that's after you have selected the target creature to destroy) the permanent with the 0 game id gets sacrificed.In the attached savegame a Swamp with 0 game id gets sacrificed.
Note In second bug if there isn't the 0 permanent in the battlefield then the spell is cancelled and returns to hand and mana stays in pool.

Which card did behave improperly?
Eliminate the Competition

Which update are you using? (date, name)Which type? (duel, gauntlet, sealed deck)
Manalink dev 778ccb5 version - duel

What exactly should be the correct behavior/interaction?
1- I think it should cancel the spell and return it to hand.
2- Certainly not sacrifice the 0 game id permanent.
However I don't know what should be the correct behavior.

Are any other cards possibly affected by this bug?
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Fixed in commit ffc3345. For 1st bug I just gave a do_dialog() so you have a last chance to cancel spell and refund mana in mana pool. Also added a choice if you want to cast it and sac/target 0 creatures.