|
Title: OP_VERIF & OP_VERNOTIF opcodes Post by: oleganza on August 13, 2013, 06:27:29 PM I don't understand why the wiki says (https://en.bitcoin.it/wiki/Script):
OP_VERIF (0x65) Transaction is invalid even when occuring in an unexecuted OP_IF branch OP_VERNOTIF (0x66) Transaction is invalid even when occuring in an unexecuted OP_IF branch From the BitcoinQT code I see that OP_VERIF and OP_VERNOTIF are undefined in the same way as OP_VER or OP_RESERVED. Meaning, if OP_VER is skipped in the if branch, then OP_VERIF is skipped as well. But the wiki says that tx will be valid if OP_VER is not executed, but will be invalid even if OP_VERIF is not executed. Is it a mistake in the wiki or I miss something here? Title: Re: OP_VERIF & OP_VERNOTIF opcodes Post by: oleganza on August 18, 2013, 12:29:38 PM Now I know why OP_VERIF and OP_VERNOTIF fail the transaction even if "not executed".
BitcoinQT walks though all operators from OP_IF to OP_ENDIF inside "non-executed" branch to keep track of nesting. Since OP_VERIF and OP_VERNOTIF are not assigned, even inside a non-executed branch they will fall in "default:" switch case and cause the script to fail. Some other ops like OP_VER can be present inside non-executed branch because they'll be skipped. Code: OP_IF = 0x63, |