User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0 Build ID: 20150903030225 Steps to reproduce: 1. Add a new rule in the ruleview 2. Use -moz-locale-dir pseudo class Actual results: -moz-locale-dir is unavailable as turns gray, but -moz-dir is available Expected results: -moz-locale-dir should be available in the ruleview

As far as I know, Nighly only uses en locale, which is ltr, and for ltr languages your screenshot matches the expectations. Please provide full list of locales where you tested it, indicating which of ":-moz-locale-dir(rtl)" and ":-moz-locale-dir(ltr)" turned gray for you on each locale. (locale is the value of the "general.useragent.locale" pref in about:config)

(In reply to arni2033 from comment #1) > As far as I know, Nighly only uses en locale, which is ltr, and for ltr > languages your screenshot matches the expectations. Please provide full list > of locales where you tested it, indicating which of ":-moz-locale-dir(rtl)" > and ":-moz-locale-dir(ltr)" turned gray for you on each locale. > (locale is the value of the "general.useragent.locale" pref in about:config) You are right! My user story is wrong. Why I have been confusing... I reconfirm this, then added a new image. Please find attached file. The left side is body[dir=ltr], The right side is body[dir=rtl]. Is this pseudo class behavior right? If this is no problem, could you please close this bug? Thank you in advance.

There're too many valid bugs, so I agree that sometimes such mistakes are possible :) For now I can tell that -moz-locale-dir pseudoclass is only used in chrome, so please don't touch it (lol). Let's just pretend that you encountered bug 588996 (it's really looks like enhancement)