Created attachment 8787695 [details] test_screen_orientation_angle.html User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.89 Safari/537.36 Steps to reproduce: 1. Hold device in portrait-primary orientation. 2. Listen for the screen.orientation change event. 3. Trigger requestFullScreen. 4. Trigger screen.orientation.lock('landscape-primary') 5. Read the screen.orientation.angle value. Tested on a Nexus 5X running Android 6.0.1 and Firefox 48.0. Actual results: The screen.orientation.angle value is 0. This would make sense if the orientation was still portrait-primary, but not for landscape-primary on this device. Expected results: The screen.orientation.angle value should be 90 for this device, as the orientation has changed to landscape-primary. See Section 4.1 of the Screen Orientation API for expected behaviour of the angle value: https://www.w3.org/TR/screen-orientation/#reading-the-screen-orientation
Thank you Cameron for the detailed steps you provided, I was able to reproduce it. However I'll make it a duplicate of bug 1112531.