importprivkey found bitcoins even with rescan set to false

[FrozenPrincess]

I imported a private key to a funded address with importprivkey {privateKey} "" false expecting that the wallet would only know about future transactions to this address. However it immediately found the funds (which had 4 confirmations), despite rescan set to false. My expectation was that it would only find funds for future transactions. Looking at the source code I can't see how this would happen and how many blocks it actually does scan back.

I'm not sure if the current behavior is intended or not, but it could be made a lot more clear

[laanwj]

Did it do a rescan?
(hard to miss, your node would hang for some time and it prints to debug.log)

[FrozenPrincess]

Yeah, there was no rescan. I am able to reproduce by:

Create an address on bitaddress.org
Send some bitcoin to that address
Wait until the bitcoin have got a couple of confirmations
Check the balance
Import private key with false set for rescan
Check the balance, and see that it found the money

[FrozenPrincess]

I'm also totally sure I didn't run with rescan, because if I try:

Rescan is disabled in pruned mode (code -4)