I just noticed that when I type 'set' in monero-wallet-cli [testnet] it prints, among other things
default-mixin = 0. From what I understand, the default mixin should be the mixin level of a transaction for which none was specified. I sent a transaction like that
transfer [my address] [amount] and it went through fine, but upon checking it out with
print_tx I see that indeed it used mixin 4. So I did
set default-mixin 2 and tried sending another transaction. As expected (mixin should be at least 4, right?), I got the message:
Error: transaction (...) was rejected by daemon with status: Failed
Error: Reason: mixin too low
So it seems that there is a bug in the default-mixin, in that it is using 4 when it is set to zero.
EDIT: I just tried to change it back to how it was at the beginning by doing
set default-mixin 0, but after doing
set it prints
default-mixin = 4. What is going on, it just identifies 4 and 0?