[confirmed]Shapesharer copy wears off at EOT

[gnomefry]

Describe the Bug:

Creatures copied with Shapesharer are reverting back to their original state at end of current turn rather than remaining as the copy until your next turn.

Which card behaved improperly?

Shapesharer

Which update are you using? (date, name)Which type? (duel, gauntlet, sealed deck)
Manalink test build Jan 12 2020 - gauntlet

What exactly should be the correct behavior/interaction?

The effect should last until your next turn begins. A copy done on your current turn would last beyond your end of turn, through your opponent's next turn and wear off as your next new turn begins.

Gatherer rulings


Are any other cards possibly affected by this bug?

[Aswan jaguar]

This needs a new mode for shapeshift_target() to be inserted in magic.exe to deal with this if I am not wrong, but without help from our devs this is mission impossible for me. We will also need this when we code Volrath, the Shapestealer.
I tried another way, which makes it work only if you copy a non-token creature BUT if you copy a token then the effect will stay for the whole game.
And I didn't test at all what happens with animated staff or any other possible case.
So, I thing it is a better to leave this as it is until a programmer can do it properly.

[gnomefry]

Thanks for looking into it, AJ.

I notice that Vesuvan Doppelganger and Vesuvan Shapeshifter both work, can copy tokens, and get the system prompt during your upkeep to change/stay-the-same.

I realize the phase (upkeep rather than untap) and prompt (choice rather than forced revert) are different, but just wondering if there's anything you can pinch from the code. Like a mandatory prompt during controller's untap phase for any Shapesharer in play on their side to become a 'base' Shapesharer?