Is your feature request related to a problem? Please describe.
When I use the bumpfee RPC it adds new inputs, potentially damaging privacy. I created the original transaction carefully using coin control to avoid linking specific UTXOs, but bumpfee undoes this by adding new inputs apparently at random.
This is further exacerbated by the way in which bumpfee decides whether to add new inputs or not. It attempts to bump the fee by reducing the change output if possible, but I label my change outputs which causes IsChange() not to recognize them as change. Any labelled UTXO is considered not to be change, which is incorrect:
bool CWallet::IsChange(const CScript& script) const
{
// TODO: fix handling of 'change' outputs. The assumption is that any
// payment to a script that is ours, but is not in the address book
// is change.
Describe the solution you’d like
I’d like to be able to tell bumpfee not to add new inputs. I see in recent release notes:
The fundrawtransaction RPC now supports add_inputs option that when false prevents adding more inputs if necessary and consequently the RPC fails.
Something like that for bumpfee would be ideal.
I’d also like to be able to bump the fee on transactions where the change is labelled without adding new inputs, and to be able to specify which new inputs to add if new inputs need adding. Basically coin control for bumpfee.
