no surprise rescan for importprivkey newbie #26115

Is your feature request related to a problem? Please describe. Calling importprivkey(1) triggers rescan. Rescan of long chains using bad and old equipment takes many days.

Describe the solution you'd like Reject importprivkey(1) completely. Deprecate in release i, disable in release i+1 (prompting user to use importprivkey(2) or importprivkey(3)), remove in release i+2.

Describe alternatives you've considered Make the program so it knows that equipment is old and chain is long, then estimate rescan is large, if so rejecting importprivkey(1) unless confirmed YES when prompted.

Additional context TBA.

importprivkey already doesn't exist for the newer descriptor wallets. You have to use importdescriptor there, which takes as argument a birth date of the key, and only rescans the necessary portion of the chain. Similar functionality is available for legacy wallets using importmulti.

RPCs are intended for program interaction though, it's very unclear how they could be made interactive like this.

Reading importdescriptors help, knowing about future wallets migration, I can agree this problem is essentially solved.