gui: Also log and print messages or questions like bitcoind #14162

Testing and debugging after shutdown are harder if the node was run through the gui, because errors and warnings would not be logged to the debug.log or written to the stderr (as is the case for bitcoind).

utACK fa7e969.

I guess calling handleMessageBox and friends is not worth it.

BTW noui.cpp is in libbitcoin_server which is shared between bitcoind and bitcoin-qt — initially thought noui.cpp wasn't included in bitcoin-qt.

utACK fa7e9694e1ed5406036620d4bf0b72a2aa984578

I'm fairly sure that this used to be the behavior, the noui handlers were always registered.

But it regressed when moving away from boost::signals in #13961, or earlier, which dropped support for having multiple handlers.

utACK fa7e9694e1ed5406036620d4bf0b72a2aa984578 anyhow.

Edit: checked that this does not need backport to 0.17.

@laanwj I am pretty sure this has always been the case.

Also, it exists on 0.17:

$ ./src/qt/bitcoin-qt -regtest -walletdir=/tmp/aaaab
$

master:

$ ./src/qt/bitcoin-qt -regtest -walletdir=/tmp/aaaab
Error: Specified -walletdir "/tmp/aaaab" does not exist
$

seems you're right, i've checked back as far as 0.10.0 and there's no noui_connect in the GUI

must have imagined it then...

I think I was confused with InitMessage, both qt and the noui implementation have (before this PR):

static void InitMessage(const std::string &message)
{
    LogPrintf("init message: %s\n", message);
}

so they were logged for both the GUI and with bitcoind

the init window also subscribes to this handler, but that's no problem, as multiple handlers for these signals are still supported (in contrast to what I thought)

Indeed, init messages are both handled. Though, not the errors, warnings and questions.