Custom fields withing ‘%’ chars not working

Sorry to bother you, but I noticed a problem after I upgraded from 5.1 to 5.2.

I have a shortcode for embedding Facebook videos. It worked in 5.1 by passing a video code as a %%code%% field like in the example below.

[sc name=”fb-video-embed-test” code=”2F655069018243083″]

The shortcode looks like this:

<p class="facebook-video-frame">
<iframe style="border: none; overflow: hidden;" src="https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2FCatsZonePage%2Fvideos%%%code%%%2F&show_text=0&width=847&mute=0" frameborder="0" scrolling="no" allowfullscreen="allowfullscreen"></iframe>
</p>

After I upgraded to 5.2, whatever I assign to the %%code%% field disappears in the HTML presented to the user. It seems that Shortcoder now has a problem with fields enclosed in ‘%’ characters (%%%code%%%).