User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.9.1b4) Gecko/20090522 Gentoo Shireoko/3.5b4 Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.9.1b4) Gecko/20090522 Gentoo Shireoko/3.5b4 In the to-be-attached example, the left border is supposed to be dotted, but it shows up as solid. It displays correctly in Firefox 2, and not quite correctly in Firefox 3.0 and 3.5. The DOM inspector shows that Firefox does understand it should be dotted, but it doesn't show up that way. Reproducible: Always I had added this to bug 491256, but reporting now as a new bug as requested.

This regressed from Bug 368247.

I would be interested to know if the latest patch (attachment 385934 [details] [diff] [review]) in bug 19963 helps with this bug.

User Agent Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:49.0) Gecko/20100101 Firefox/49.0 Build ID 20160526082533 I tested this on latest Nightly (49.0a1) and the left border is dotted. However I observed another strange behavior in the testcase regarding the bottom edges of the borders. For better understanding I will attach a screenshot showing the issue and how other browsers render the testcase.

This seems to work fine now.