Paste "foo<div>bar</div>" into <div><br></div> and you'll get an extraneous line break.
Created attachment 7992 [details] patch, layout tests and changelog entries this helps me get set up for other changes
Created attachment 7993 [details] patch, layout tests and changelog entries fixed typos
Comment on attachment 7993 [details] patch, layout tests and changelog entries r=me
fixed in r14086