Empty inline leak

[Frederico Caldeira Knabben]

1. Go to source and paste this:

<p>One Two</p>

2. Back to wysiwyg, put the caret right after "One".
3. CTRL+B to bold the collapsed selection.
4. Without typing, switch to source. We'll have this:

<p>One<strong>​</strong> Two</p>

The weird thing is that this doesn't happen if you simply type "One Two" in step 1. You must go source and back.

[Piotrek Koszuliński]

Will be fixed by #10315.