Original Bootstrap bug report: https://github.com/twbs/bootstrap/issues/17546
The parser fails to display correctly some CSS hacks for IE, like "#000\9", see bug 787981. http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9a6d708faf3f&tochange=b959971b8219 Before: Expected color but found '#000 '. After: Expected color but found '#\30 00\9 '.
Inside that changeset from comment#2 is http://hg.mozilla.org/mozilla-central/rev/b11550b854e8 bug#229827 escape unprintable characters in CSS parser diagnostics. r=dbaron When you link Bug#787981 do you know that is the cause, or just that the problem was introduced in that changeset ? Also how did you bisect back to 2012 so fast? kudos to you :)
Missed that bug, anyway, even before 2012-11, the parsing is wrong, it should display \9.
The '\30 ' is happening because the diagnostic printer (specifically, nsCSSToken::AppendToString) doesn't bother distinguishing eCSSToken_ID and eCSSToken_Ref -- the only difference between them is that one can have an unescaped digit as the first character after the '#' and one can't. (I don't remember off the top of my head which is which.) That will be easy to fix. The '\9' is necessary (do I understand correctly that it appears in the code?) The space after the '\9' will be hard to get rid of, since the logic that prints these messages does not have access to the original source text and does not know what will be printed *after* the escape. I might be able to kludge in a correction for escapes at the very end of the token being printed, but I'll have to convince myself it's always safe. Anyway, I can find time to write the code change to fix this, but I can *not* find time to minimize a test case. I need one of you to do that. Please give me something that can be dropped directly into the test suite. There are similar tests somewhere in layout/style mochitests and dbaron will be happier if you reuse existing infrastructure ;-)
It would be interesting to see what this prints in a Firefox nightly that has layout.css.servo.enabled set to true.
The output is the same: Expected color but found ‘#\30 00\9 ’. Error in parsing value for ‘color’. Declaration dropped. http://software.hixie.ch/utilities/js/live-dom-viewer/?%3C!DOCTYPE%20html%3E%0A%3Cstyle%3Ex%7Bcolor%3A%23000%5C9%7D%3C%2Fstyle%3E%20
On the new console frontend, I do see the following : `Expected color but found ‘#000\9 ’. Error in parsing value for ‘background-color’. Declaration dropped.`