From d74d4abefc72aeb66f3063a074889100e7cfa155 Mon Sep 17 00:00:00 2001
From: Leon Costa <leon.costa@protonmail.com>
Date: Thu, 4 Jul 2024 18:50:17 +0200
Subject: [PATCH] Fix wallet load error on incomplete gettransaction

The error happens when the wallet has some locked outputs in
`listlockunspent` and the corresponding `gettransaction` doesn't contain
the details of this particular output.

It may be related to https://github.com/bitcoin/bitcoin/issues/28555. It
is at least the same symptom.

The locked outputs were locked by creating a transaction in Specter.
This has happened to me multiple times.

The UI says it failed to load the wallet with the following error:
Failed to load utxos, IndexError: list index out of range

The raw transaction does contain the missing output so we use that
instead.

Here's an example that generates the error:
listlockunspent:
[
  {
    "txid": "<some txid>",
    "vout": 0
  }
]

gettransaction <some txid>:
{
  "amount": <redacted>,
  "fee": <redacted>,
  "confirmations": <redacted>,
  "blockhash": "<redacted>",
  "blockheight": <redacted>,
  "blockindex": <redacted>,
  "blocktime": <redacted>,
  "txid": "<some tx id>",
  "wtxid": "<redacted>",
  "walletconflicts": [
  ],
  "time": <redacted>,
  "timereceived": <redacted>,
  "bip125-replaceable": "no",
  "details": [
    {
      "address": "<redacted>",
      "category": "send",
      "amount": <redacted>,
      "label": "<redacted>",
      "vout": 1,
      "fee": <redacted>,
      "abandoned": false
    }
  ],
  "hex": "<some raw tx hex>",
  "lastprocessedblock": {
    "hash": "<redacted>",
    "height": <redacted>
  }
}

decoderawtransaction <some raw tx hex>:
{
  "txid": "<some txid>",
  "hash": "<redacted>",
  "version": 2,
  "size": <redacted>,
  "vsize": <redacted>,
  "weight": <redacted>,
  "locktime": <redacted>,
  "vin": [
    {
      "txid": "<some other txid>",
      "vout": 0,
      "scriptSig": {
        "asm": "",
        "hex": ""
      },
      "txinwitness": [
        "<redacted>",
        "<redacted>"
      ],
      "sequence": <redacted>
    }
  ],
  "vout": [
    {
      "value": <redacted>,
      "n": 0,
      "scriptPubKey": {
        "asm": "<redacted>",
        "desc": "<redacted>",
        "hex": "<redacted>",
        "address": "<redacted>",
        "type": "<redacted>"
      }
    },
    {
      "value": <redacted>,
      "n": 1,
      "scriptPubKey": {
        "asm": "<redacted>",
        "desc": "<redacted>",
        "hex": "<redacted>",
        "address": "<redacted>",
        "type": "<redacted>"
      }
    }
  ]
}
---
 src/cryptoadvance/specter/wallet/wallet.py | 23 ++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/cryptoadvance/specter/wallet/wallet.py b/src/cryptoadvance/specter/wallet/wallet.py
index 4340b3d8f..6b6d1ca94 100644
--- a/src/cryptoadvance/specter/wallet/wallet.py
+++ b/src/cryptoadvance/specter/wallet/wallet.py
@@ -718,13 +718,28 @@ def check_utxo(self):
                 else:
                     tx_from_core = self.rpc.gettransaction(tx_copy["txid"])
                     # in the case of locked amounts, the stupid listlockunspent call does not contain reasonable utxo-data
-                    searched_vout = [
+                    searched_vouts = [
                         _tx
                         for _tx in tx_from_core["details"]
                         if _tx["vout"] == utxo_vout
-                    ][0]
-                    tx_copy["amount"] = searched_vout["amount"]
-                    tx_copy["address"] = searched_vout["address"]
+                    ]
+                    if len(searched_vouts) > 0:
+                        searched_vout = searched_vouts[0]
+                        tx_copy["amount"] = searched_vout["amount"]
+                        tx_copy["address"] = searched_vout["address"]
+                    else:
+                        # Sometimes gettransaction doesn't return the complete list of outputs.
+                        # It may be related to https://github.com/bitcoin/bitcoin/issues/28555
+                        # In this case we decode the raw transaction to get the data we want.
+                        raw_transaction_hex = tx_from_core["hex"]
+                        raw_transaction = self.rpc.decoderawtransaction(raw_transaction_hex)
+                        searched_raw_vout = [
+                            _output
+                            for _output in raw_transaction["vout"]
+                            if _output["n"] == utxo_vout
+                        ][0]
+                        tx_copy["amount"] = searched_raw_vout["value"]
+                        tx_copy["address"] = searched_raw_vout["scriptPubKey"]["address"]
 
                 # Append the copy to the _full_utxo list
                 _full_utxo.append(tx_copy)