Calculating fees, in the transaction #10741

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Describe the issue

Can you reliably reproduce the issue?

If so, please list the steps to reproduce below:

1. Enter a wallet address and amount to transfer, minus the advertised fee
2. Enter your key, watch the error result
3. The "fee" keeps changing and therefore the transaction cannot be completed

Expected behaviour

Tell us what should happen

The calculation UI should be a better UX where the fee and transfer amount (ie: your wallet contents) should be calculated on the fly, ready to go. The UI doesn't allow the fee to be copied-and-pasted (perhaps an oversight), where your balance can. So multiple issues in this UI that need fixing.

Actual behaviour

Tell us what happens instead

Each time I go to transfer an amount, the "fee" stays the same, but the error window after continues to change in small amounts. For example the "fee" on the UI is static at 0.0002xxx but the error window complains about the amount exceeding minus the fee 0.0003xxx. This is very problematic.

Screenshots.

If the issue is related to the GUI, screenshots can be added to this issue via drag & drop.

What version of bitcoin-core are you using?

List the version number/commit ID, and if it is an official binary, self compiled or a distribution package such as PPA.

v0.14.2 (64-bit)

Machine specs:

• OS: OSX Sierra
• CPU:
• RAM: 32GB
• Disk size: 1TB
• Disk Type (HD/SDD): SDD

Any extra information that might be useful in the debugging process.

This is normally the contents of a debug.log or config.log file. Raw text or a link to a pastebin type site are preferred.

The fee you see in the GUI "send" dialog is not an absolute fee, it's a feerate (fee per KB). That's because once you try to create the transaction, the size of it, depends on how many inputs where selected. If you want to send an amount where the fee is included (reduced from your total and not added on top), try to "subtract fee from amount" checkbox next to the amount input field.

Works?

Is this still relevant?