User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:37.0) Gecko/20100101 Firefox/37.0 Build ID: 20170329150849 Steps to reproduce: 1. Go to userstyles.org 2. Middle-click "Help" or "Contact" in the footer Actual results: The current tab is navigated, despite this being a middle-click on an <a> element with a valid "href". (Indicating a regression to Chrome-like click event-handling behaviour) Expected results: The middle-click should have an effect identical to right-clicking and choosing "Open Link in New Tab" and the site should not be able to override this.
Whoops. I just realized that I forgot to manually set my version information to 52 ESR. (I'm using User-Agent randomization to mitigate browser fingerprinting.) Could someone please correct that?
It's not specific to userstyles.org nor a bug in Firefox; it's possible for websites to override the standard click behaviour. Some sites are tracking link clicks for analytics purposes, and such issues can happen when they don't consider right- or middle-click. Please report the issue to the site.
It's a regression in Firefox. Firefox didn't used to require sites to handle middle clicks specially in their progressive enhancement code. That was a very noticeable difference from Chrome that I would call attention to and demonstrate.