Bug 245848

We’ve discovered an issue playing mobile web videos served from parent domain https://www. espn.com on an iPhone device running iOS16. Whenever we attempt to expand a playing video into full screen, the video expands for a brief moment but immediately contracts out of full screen. We’ve done various validations and have ruled out our client code as well as our video provider (bright cove) client code. Our findings have lead us to believe this defect is specific to our https://www.espn.com domain. To reproduce this defect: - navigate to https://www.espn.com on an iPhone running iOS 16. - remain within the mobile web experience - find a video on the site - initiate playback of the video - post ad, and once the video is playing, click on the full-screen option You should see the video launch into full-screen mode but immediately retract in size. Post these events the browser will become unstable and will eventually crash. This has been reproduced on iOS16 devices: iPhone -13, 11 pro max, XS max Browsers - Safari, Chrome Below is the test we set up that leads us to reach out to Apple for help. Below is a Brightcove test ruling out our front-end client code base. It is a simple Html file with the Brightcove video player framed in. https://www.espn.com/test/videos/bc.html To rule out Brightcove video player a similar Html file was created, but this time a YouTube video was embedded. https://www.espn.com/test/videos/yt_video.html To further validate our working theory, running the same test against our QA domains works as expected. https://www.espnqa.com/test/videos/bc.html?espn=cloud Https://www.espnqa.com/test/videos/yt_video.html?espn=cloud This has led us to believe that there is something specific to our apex domain and iOS16 and has resulted in this defect. In digging through the git repo we stumbled across the following https://github.com/WebKit/WebKit/blob/249fdd9c0f8bf064190f69a2791917b762922bee/Source/WebCore/page/Quirks.cpp#L1516 it is not clear why this is needed but seems to be a likely culprit.