show proper error when change is below dust threshold

[jackstar12]

Currently, an Insufficient funds for fees error is thrown when the change amount is below dust threshold which is confusing to the user:

gdk/src/ga_tx.cpp

Line 566 in c3a77be

throw user_error("Insufficient funds for fees"); // FIXME res::

If this condition is true and no more utxos are available, a proper error should be thrown:

gdk/src/ga_tx.cpp

Line 535 in c3a77be

if (change_amount <= dust_threshold) {

E.g. Change is below dust threshold

[jgriffiths]

Hi @jackstar12, thanks for reporting.

This will be fixed in release 0.73.4 which will include this WIP branch with the fix: https://github.com/Blockstream/gdk/tree/dusty_fee the fix is now in master.

Note the error text will be "Fee change below the dust threshold".

[jgriffiths]

Fixed in release https://github.com/Blockstream/gdk/releases/tag/release_0.73.4