User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:220.127.116.11) Gecko/20070309 Firefox/18.104.22.168 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:22.214.171.124) Gecko/20070309 Firefox/126.96.36.199 After what appears to be just removing a linebreak in an editor window, the text from the line before the break ends up after the text from the line after the break. This appears to only occur when a <span> contains a <div>. The <div> contents end up before the <span> contents. Reproducible: Always Steps to Reproduce: 1. Load the test case that will be attached. 2. Place the caret at the end of the "(Start" line. 3. Hit the delete key to remove the linebreak and join the lines. Actual Results: The text in the editor now appears as: end)(Start Expected Results: The text should appear as (Start end) on a single line.