"Over the size limit" txs shouldn't force cancellation. #1629

When bitcoin-qt's "over the size limit" warning is triggered and an additional transaction fee is suggested, the client currently gives the options of "continue" or "cancel". This is problematic because, as I understand it, the bitcoin network does not truly mandate fees, particularly not in the amount shown (which is sometimes egregious), and a user could continue to submit the transaction and wait for a miner to process without the additional suggested fee.

The dialog should be modified to allow the user to send the coins without forcing attachment of bitcoin-qt's suggested fee.

See https://bitcointalk.org/index.php?topic=11613.0 for more discussion on this (at this point, thread is over a year old).

The claimed fee in that thread is incorrect, IIRC they showed up in IRC later and it was discovered that the fee was actually 0.59 or something like that. (this event happened on older software with min-fee for non-free transactions set to 0.01/KB)

Current versions of the reference software is unable to generate a transaction which would result in a compulsory fee of more than 0.05 BTC. (100kb * 0.0005BTC/KB)

Your peers do indeed enforce minimum fees in order to relay transactions which are objectively indistinguishable from a DOS attack— otherwise someone with a simple shell script could flood bitcoin to oblivion. If you were to force your client to attempt to spend anyways in cases where it knows that it itself (thus its peers) wouldn't relay the transaction you would potentially end up with a stuck transaction which makes somewhere between its value and your entire wallet balance unspendable forever until someone helps you hex edit your wallet to kill the stuck transaction.

So, continue-anyways is a non-starter until we have a way to safely cancel a stuck transaction.

@gmaxwell This is still a bug. Software should give the user the choice of not paying, not take it away from him.

This dialog sorta explains itself:

Ok compiled bitcoin-qt from master, and playing on stuff with TestNet. New dialog, still enforces the fee, but slightly less confusing message

Closing this as it is working as intended. The fee is necessary otherwise your transaction will not even get relayed by peers (let alone included into a block), which results in a stuck and useless transaction. Overall changes to the fee system are underway, but this will not change.