Why is this not making a plus sign?
<p>I have:</p>

<pre><code>$str = 'test%2B';
echo html_entity_decode($str);
</code></pre>

<p>I want it to return <code>test +</code> </p>

<p>What am I doing wrong?</p>

<p>NOTE: Sorry, the string cannot be modified.  It's from an external source, I just need to make it replace the %2B with + signs somehow with PHP.</p>
