To reproduce:

1. Open the attached file (editor-bold-justifyleft.html) in the browser
2. Click the "bold" link at the top of the page
3. Type "foo" in the text area below
4. Click the "bold" link again
5. Press ENTER
6. Click the "justifyleft" link
7. Type "bar" in the text area

Or:

1. Uncomment the lines below the "Automated test" comment in the attached file and open the file in the browser

Expected result: The second line, "bar", should appear in normal, non-bold font.

Actual result: The second line, "bar", unexpectedly appears in bold font.

Note that if you do not click the "justifyleft" link, the second line appears in normal, non-bold font, as expected.