[RPC] Fee reported by gettransaction is incorrect

[matsjj]

Describe the issue

Since updating to the latest version of bitcoin abc the gettransaction RPC endpoint returns absurdly high values for fees.

Can you reliably reproduce the issue?

If so, please list the steps to reproduce below:

1. Import address
2. Wait for resync to finish
3. Retrieve one transaction

bitcoin-cli importaddress qryz5e9nxtexve3z3ah94mlj30z4fctp5y8kaahzuw "" true bitcoin-cli gettransaction f37a8639da8f1f66a634303b132817169a8c29d4fe7256184b9ed5d016bf345f true

{
  "amount": -24.22919216,
  "fee": 20.92919216,
  "confirmations": 1670,
  "blockhash": "00000000000000000119d866eaa40d1a00c08b6edf364fce61ed2b75a29dcf8d",
  "blockindex": 912,
  "blocktime": 1567055513,
  "txid": "f37a8639da8f1f66a634303b132817169a8c29d4fe7256184b9ed5d016bf345f",
  "walletconflicts": [
  ],
  "time": 1568031302,
  "timereceived": 1568031505,
[...]
}

Expected behaviour

The fee does not match the actual fee paid in this transaction, which is 0.00015 BCH https://blockchair.com/bitcoin-cash/transaction/f37a8639da8f1f66a634303b132817169a8c29d4fe7256184b9ed5d016bf345f

What version of bitcoin-abc are you using?

bitcoin-cli --version Bitcoin ABC RPC client version v0.19.12.0-29ec9c357