Where is the code making OP_RETURN a standard transaction type?

Question

I am looking through the bitcoin github history. I am trying to find the commit where OP_RETURN became accepted as a standard tx. This was included in the changelog for Bitcoin Core 0.90. Any help would be appreciated.

I'm looking through the Script Solver and see where OP_RETURN is included as a type in the template, but don't see where it returns true for any null data case.

Thanks.

Answer 1

This is the PR that made OP_RETURN outputs standard:

https://github.com/bitcoin/bitcoin/pull/2738

The commit:

https://github.com/jgarzik/bitcoin/commit/a79342479f577013f2fd2573fb32585d6f4981b3

The current code:

https://github.com/bitcoin/bitcoin/blob/v0.11.0/src/script/standard.cpp#L56-L58

    if (GetBoolArg("-datacarrier", true))
        mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN << OP_SMALLDATA));
    mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN));

Answer 2

Here:

bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsigned char> >& vSolutionsRet)
[...]
    // Empty, provably prunable, data-carrying output
    if (GetBoolArg("-datacarrier", true))
        mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN << OP_SMALLDATA));
    mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN));

https://github.com/bitcoin/bitcoin/blob/ddd8d80c63182aefea56abf743bb9199d9602544/src/script/standard.cpp#L40