On Wed, Aug 09, 2017 at 04:13:35PM +0000, Mark Svancarek via UA-discuss wrote:
Actually, we recently discovered an Edge bug (via the browser review) where the order of labels in a RTL.RTL.ASCII domain name were transposed during rendering. So I like calling it out explicitly.
This has been a regularly-recurring bug in various rendering engines since at least 2008, because I recall the demonstrations of it during the idnabis WG, and then seeing it in a completely different context during the VIP work for ICANN in 2011 or '12. It's not always only Arabic: at least one of the examples was reproducible in any bidi context. I seem to recall one example where the wire order [firstlabel]RTL[secondlabel]RTL[thirdlabel]LTR[fourthlabel]NULL got rendered as RTL.LTR.RTL Which I thought was a pretty cool bug. I have no idea how it happened that way, though I recall walking mysef through the bidi algorithm at the time and figuring out what the problem must have been. Bidi is hard. I therefore think it wise not to call out Arabic especially -- but maybe point out that Arabic is perhaps the most prominent writing system that uses RTL, so that programmers aren't tempted to dismiss the problem as a "corner case". Big corner, the Arabic-using population! Best regards, A -- Andrew Sullivan ajs@anvilwalrusden.com