Is this transaction spendable?

[rapport]

maybe its about the fees?

amaclin has answered above

[1715078937]

1715078937

[poutine310]

I created this transaction and it is in fact unspendable due to the fact the alt stack does not persist from the scriptSig to the scriptPubKey. I'm glad it sparked some discussion though.

[Yoghurt114]

I'm curious though.

Can anyone think of a script that uses the altstack and can do something no other script can?

[DeathAndTaxes]

I'm curious though.

Can anyone think of a script that uses the altstack and can do something no other script can?

An m of n PubKeyHash (as opposed to PubKey) multisig.  I haven't exhaustively tested it so there may be some clever solution I just didn't see but anything not involving altstack ends up being much longer and more complex.

[amaclin]

Can anyone think of a script that uses the altstack and can do something no other script can?

Some algorithms will be much more shorter using the altStack.
For example this script is only 10 bytes long

Code:

OP_TOALTSTACK 
OP_TOALTSTACK 
OP_TOALTSTACK
OP_HASH160
OP_FROMALTSTACK
OP_HASH160
OP_FROMALTSTACK
OP_HASH160
OP_FROMALTSTACK
OP_HASH160

and (I can be wrong, please correct me) replaces 4 values on the top of the stack with their hashes, leaving the original order.
Try to do the same without altStack in less than 10 bytes.

Update1: OK, may be it is possible to do with OP_2DUP and OP_2SWAP opcodes. You can try to find out your own examples for using altStack

Update2: Note, that bitcoin script language is not Turing-complete. Not all things are even possible with current opcode set

[TimS]

I'm curious though.

Can anyone think of a script that uses the altstack and can do something no other script can?

I'm pretty sure that theoretically, there's nothing you can do with altstack that you can't without (given enough space). However, it can make some things simpler/shorter, and since there is a limit on the script size, that can make it quite useful.

[rollingMyCar]

what is altstack?
do you have some tutorials?

thanks

[amaclin]

what is altstack?
do you have some tutorials?

thanks

it is alternative/secondary stack
it is not used now for standard scripts
but the operations are valid

[rollingMyCar]

what is altstack?
do you have some tutorials?

thanks

it is alternative/secondary stack
it is not used now for standard scripts
but the operations are valid

Where i can get more info a bout altstack?
Do you Have some docs or links?
Thanks!

[Muhammed Zakir]

what is altstack?
do you have some tutorials?

thanks

it is alternative/secondary stack
it is not used now for standard scripts
but the operations are valid

Where i can get more info a bout altstack?
Do you Have some docs or links?
Thanks!

See https://bitcoin.org/en/developer-guide#p2pkh-script-validation

   ~~MZ~~