Steps to reproduce
- Copy some text, some of which is struck out with a <del> element and some of which isn't. For example, this sentence: "
- Try to paste it into the visual editor.
- Only the text which isn't struck out will appear.
This is particularly problematic because deleted text in Mediawiki diffs is marked up with a non-displayed <del> element. For example, the text removed in this edit will be copied as <del>He</del> <del>was</del> <del>a</del> <del>serving</del> <del>soldier</del>. If this is pasted into the visual editor, only the spaces will appear.
Verified in Firefox 41 and Chrome 44.