`searchform` uses id in single instances *and* class in second instance

Just came across this issue today while testing 3.6-alpha (uncertain if it is directly related).

Using two instances of the plugin appears to cause the searchform to use different elements?!

See this site https://wpthemes.edwardcaissie.com/ as an example (I’ll leave the current theme active for a while as it makes the visual more obvious). This occurs with every theme I have checked so far.

The first instance of the plugin uses:

<li id="monster-widget-placeholder-11" class="widget widget_search">
<h2 class="widgettitle">Search</h2>
<form id="searchform" class="searchform" action="https://wpthemes.edwardcaissie.com/" method="get" role="search">
<div>
<label class="screen-reader-text" for="s">Search for:</label>
<input id="s" type="text" name="s" value="">
<input id="searchsubmit" type="submit" value="Search">
</div>
</form>
</li>

… while the second instance of the plugins uses this:

<li id="monster-widget-placeholder-26" class="widget widget_search">
<h2 class="widgettitle">Search</h2>
<form class="searchform" action="https://wpthemes.edwardcaissie.com/" method="get" role="search">
<div>
<label class="screen-reader-text" for="s-1">Search for:</label>
<input id="s-1" type="text" name="s" value="">
<input type="submit" value="Search">
</div>
</form>
</li>

I haven’t looked into the plugin code, yet, just tested with a few different themes to see if it occurs elsewhere.

https://www.ads-software.com/extend/plugins/monster-widget/