Quote from: btc4ever on September 27, 2014, 01:08:04 AM

I'm not saying the proposed API change is perfect... actually perfection to me would be if I could write app code something like:

Quote

// business application pseudo-code

while( num_tries++ < max_tries ) {

fee = rpc.calcsendfee( address, amount )

if( not fee_is_ok( fee ) )
break;

code = rpc.sendtoaddress( address, amount, .., fee )

if( code != insufficient_fee ) {
break;
}
}

You seem to be missing the crucial fact: the coin selector in the "send" is a stochastic knapsack solver. For any non-trivial wallet it pseudo-randomly selects different coins resulting in a different size of the transaction and thus requiring a different minimal fee. This has been discussed many times on this forum, please use search.