[email protected] tx.id() not equal to rpc getblock(blockhash, 1) tx id

[86chenjie]

test code:

it('check_tx_id', async function () {
    // test 147056 / 00000000000007a678f2e1316e0f7f7acf2b967d998558aed8dadcd4430fd5f1
    const height = 147056
    const blockhash = await chain.getblockhash(height)
    const chain_block_hex = await chain.getblock(blockhash, 0)
    const chain_block = await chain.getblock(blockhash, 1)
    const chain_tx0_id = chain_block.tx[0]

    const block = bsv.Block.fromBuffer(Buffer.from(chain_block_hex, 'hex'))
    const block_tx0_id = block.txs[0].id()
    
    console.log(chain_tx0_id)
    console.log(block_tx0_id)
    expect(chain_tx0_id).to.equal(block_tx0_id);
  });

The two tx ids should be equal. Obviously block_tx0_id is not correct.

  2) bsv
       check_tx_id:

      AssertionError: expected '9fa47592276963ff2b8d44d0f547b03a41ac1e4e18e2a02b5445ade9b021071d' to equal '121f0f093c0e98bb499643bbe781a9746deaf4b9b123f958b2a962b3bb57d873'
      + expected - actual

      -9fa47592276963ff2b8d44d0f547b03a41ac1e4e18e2a02b5445ade9b021071d
      +121f0f093c0e98bb499643bbe781a9746deaf4b9b123f958b2a962b3bb57d873

      at Context.<anonymous> (test/chain.spec.js:59:29)
      at process._tickCallback (internal/process/next_tick.js:68:7)

[calvogenerico]

I've been able to recreate this too. I used the tools included in the repo and files instead of an rpc connection:

it('parse a hex block generate the right txids', async () => {
    // const height = 147056
    // const blockHash = '00000000000007a678f2e1316e0f7f7acf2b967d998558aed8dadcd4430fd5f1'
    const blockHex = await new Promise(resolve => {
      fs.readFile('test/block.txt', 'utf-8', (err, data) => {
        if (err) {
          throw err
        }
        resolve(data)
      })
    })
    const blockDataFromRpc = await new Promise(resolve => {
      fs.readFile('test/block.json', 'utf-8', (err, data) => {
        if (err) {
          throw err
        }
        resolve(JSON.parse(data))
      })
    })
    const blockFromLibrary = Block.fromBuffer(Buffer.from(blockHex, 'hex'))

    const firstTxIdFromRpc = blockDataFromRpc.tx[0]

    const firstTxIdFromLibrary = blockFromLibrary.txs[0].id()

    const otherTxidsFromParsedBlock = blockFromLibrary.txs.map(tx => tx.id()).slice(1)
    const otherTxIdsFromRawBlock = blockDataFromRpc.tx.slice(1)

    should(otherTxidsFromParsedBlock).be.eql(otherTxIdsFromRawBlock)
    should(firstTxIdFromRpc).be.eql(firstTxIdFromLibrary)
  })

It fails exactly as in the report.

[calvogenerico]

The issue happens parsing this script:
fc70035c7a81bc6fcc36947f7c1b2d63620560bec2aa336a676213bab74c9f03d46788100dca84c0f19a0f1c14ef0d67f3fc63c011ba4787510d55fde9554e554e

The first thing that I notice is that there is a weird behavior when I tried to encode it using different languages:

const weirdScript = bsv.Script.fromHex('fc70035c7a81bc6fcc36947f7c1b2d63620560bec2aa336a676213bab74c9f03d46788100dca84c0f19a0f1c14ef0d67f3fc63c011ba4787510d55fde9554e554e')

weirdScript.toString()
// => '0xfc OP_2OVER 3 0x5c7a81 0xbc OP_3DUP 0xcc 54 0x947f7c1b2d63620560bec2aa336a676213bab74c9f03d46788100dca84c0f19a0f1c14ef0d67f3fc63c011ba4787510d55fde9554e55 OP_PUSHDATA4 0 0x'
weirdScript.toAsmString()
// => 'fc OP_2OVER 5c7a81 bc OP_3DUP cc 947f7c1b2d63620560bec2aa336a676213bab74c9f03d46788100dca84c0f19a0f1c14ef0d67f3fc63c011ba4787510d55fde9554e55'

the asm version doesn't include the last push data. And the last push data is causing the issue.

[calvogenerico]

Bsv legacy fails when trying to parse that as a script:

bsv.Script.fromHex('fc70035c7a81bc6fcc36947f7c1b2d63620560bec2aa336a676213bab74c9f03d46788100dca84c0f19a0f1c14ef0d67f3fc63c011ba4787510d55fde9554e554e')

Invalid script buffer: can't parse valid script from given buffer fc70035c7a81bc6fcc36947f7c1b2d63620560bec2aa336a676213bab74c9f03d46788100dca84c0f19a0f1c14ef0d67f3fc63c011ba4787510d55fde9554e554e
Uncaught Error
    at new NodeError (/home/migue/Projects/yours/money-button/node_modules/bsv/lib/errors/index.js:20:41)
    at Function.Script.fromBuffer (/home/migue/Projects/yours/money-button/node_modules/bsv/lib/script/script.js:100:15)
    at new Script (/home/migue/Projects/yours/money-button/node_modules/bsv/lib/script/script.js:33:19)
    at Function.Script.fromHex (/home/migue/Projects/yours/money-button/node_modules/bsv/lib/script/script.js:192:10)
    at repl:1:8
    at Script.runInThisContext (vm.js:120:20)
    at REPLServer.defaultEval (repl.js:431:29)
    at bound (domain.js:426:14)
    at REPLServer.runBound [as eval] (domain.js:439:12)
    at REPLServer.onLine (repl.js:759:10)

[86chenjie]

@hojarasca thanks for the response. Looking forward the fix. This issue really block my progress. Thanks again.

[86chenjie]

any progress?

[86chenjie]

@ryanxcharles can you help to check? Thanks!

[86chenjie]

@hojarasca Your comment is correct. The root cause is the script parse process.
I checked the Script file. Personally i think the exception handling is not correct.
When the script is not valid, the script chunks should be like this: [{buf:'whole_script_buf'}]. So we can make sure the Script.toBuffer is the same with the buf in Script.fromBuffer(buf).
In this way, the fix should be very easy and fast.

[86chenjie]

Workaround is here : 86chenjie@fe41812

[calvogenerico]

This has been open for ever. I'm going to make time to fix this next week.