The basic script for a lightning network HTLC output has a conditional branch which requires a user to know a preimage of a hash. It also requires the user to give a valid signature, but it got me thinking, what if before P2SH was a thing (back in the day) a user created a locking script which just so happens to match the P2SH template? For whatever reason, the user only intended to lock the bitcoin with a “spender must know the preimage of this hash” requirement. But this preimage is not a bitcoin script itself, so can’t be executed even though it matches the P2SH template. Do P2SH-knowing nodes lock this bitcoin forever?
