Non image caption shortcode lost when switching from text to visual editor and back

[mark-k]

1. Add the line in text editor

   [caption caption="test" width="300"]Checkuot this text[/caption]
   

2. switch to visual editor

3. switch back to text and you get

   <dl class="wp-caption alignnone" id="" style="width: 310px;"><dt class="wp-caption-dt">Checkuot this text</dt><dd class="wp-caption-dd">test</dd></dl>
   

Reproduced in 3.4 as well. In 3.3 and earlier, only "Checkout this text" remains.

Seems related, though I haven't checked pre-3.5. If you have a normal captioned image, but remove the width attribute, for example:

[caption id="attachment_67" align="alignnone" width="300"]
<img class="size-medium wp-image-67" alt="caption" src="http://local.dev/stable/wp-content/uploads/2012/11/cropped-tree-300x149.png" height="149" /> caption[/caption]

Then switching to visual and back strips away the shortcode entirely leaving you with:

<img class="size-medium wp-image-67" alt="caption" src="http://local.dev/stable/wp-content/uploads/2012/11/cropped-tree-300x149.png" height="149" />