Created attachment 380752 [details]
**What steps will reproduce the problem?**
This doesn't seem noticeable right now because markers can only be numbers or symbols.
However, in bug 167729 I plan to add list-style-type:<string>, which will make it possible to use arbitrary strings in markers.
The problem is when that string has mixed-bidi:
<li style="list-style-type: '\31\627\644\32'">list-item</li>
**What is the expected result?**
The marker should be rendered with U+0031 (1), U+0032 (2), U+0644 (ل), U+0627 (ا).
**What happens instead?**
The marker is rendered with U+0031 (1), U+FEFB (ﻻ), U+0032 (2).