 be called instead of the
<em>git commit-tree</em> command, with arguments of the form
"&lt;TREE_ID&gt; [(-p &lt;PARENT_COMMIT_ID&gt;)&#8230;&#8203;]" and the log message on
stdin.  The commit id is expected on stdout.</p>
<div class="paragraph">
<p>As a special extension, the commit filter may emit multiple
commit ids; in that case, the rewritten children of the original commit will
have all of them as parents.</p>
</div>
<div class="paragraph">
<p>You can use the <em>map</em> convenience function in this 