The output for [[Image:Bad.jpg|thumb=Foobar.jpg|Title]] is:

<div class="thumb tright"><div class="thumbinner" style="width:1943px;"><a href="/wiki/File:Foobar.jpg" class="image"><img alt="" src="http://example.com/images/3/3a/Foobar.jpg" width="1941" height="220" class="thumbimage" srcset="http://example.com/images/0/09/Bad.jpg 1.5x, http://example.com/images/0/09/Bad.jpg 2x" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:Bad.jpg" class="internal" title="Enlarge"><img src="/skins/common/images/magnify-clip.png" width="15" height="11" alt="" /></a></div>Title</div></div></div>

This has several problems:

1. This output is from parserTests, where Bad is supposed to be a blacklisted image; that doesn't seem to be getting caught.
2. presumably the <a href> link should be to the image (ie, Bad.jpg) not to the thumbnail
3. the src and srcset are inconsistent. (Using the thumbnail for src but the original image for srcset.)

Version: 1.21.x
Severity: normal