user10229: 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.

user2306: 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

user18196: 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));


10229: <p>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. </p>

<p>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.</p>

<p>Thanks.</p>
 2306: <p>Here:</p>

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

<p><a href="https://github.com/bitcoin/bitcoin/blob/ddd8d80c63182aefea56abf743bb9199d9602544/src/script/standard.cpp#L40" rel="nofollow">https://github.com/bitcoin/bitcoin/blob/ddd8d80c63182aefea56abf743bb9199d9602544/src/script/standard.cpp#L40</a></p>
 18196: <p>This is the PR that made OP_RETURN outputs standard:</p>

<blockquote>
  <p><a href="https://github.com/bitcoin/bitcoin/pull/2738" rel="nofollow">https://github.com/bitcoin/bitcoin/pull/2738</a></p>
</blockquote>

<p>The commit:</p>

<blockquote>
  <p><a href="https://github.com/jgarzik/bitcoin/commit/a79342479f577013f2fd2573fb32585d6f4981b3" rel="nofollow">https://github.com/jgarzik/bitcoin/commit/a79342479f577013f2fd2573fb32585d6f4981b3</a></p>
</blockquote>

<p>The current code:</p>

<blockquote>
  <p><a href="https://github.com/bitcoin/bitcoin/blob/v0.11.0/src/script/standard.cpp#L56-L58" rel="nofollow">https://github.com/bitcoin/bitcoin/blob/v0.11.0/src/script/standard.cpp#L56-L58</a></p>
</blockquote>

<pre><code>    if (GetBoolArg("-datacarrier", true))
        mTemplates.insert(make_pair(TX_NULL_DATA, CScript() &lt;&lt; OP_RETURN &lt;&lt; OP_SMALLDATA));
    mTemplates.insert(make_pair(TX_NULL_DATA, CScript() &lt;&lt; OP_RETURN));
</code></pre>
