Bug 234850 – [GTK] Drag and drop operations within an Epiphany web app (such as Google Calendar) are unreliable / fail randomly

• Component: WebKitGTK
• Status: NEW

[Jeff Fortin]

Created attachment 448304 [details]
Screencast video

From https://gitlab.gnome.org/GNOME/epiphany/-/issues/1675 :

The test case for this is https://calendar.google.com

In that web app, drag & drop functionality to create multi-day events does not work reliably.

As you can see in the attached screencast video, when it fails, the drag is not interpreted as a drag, and instead as a selection, so it selects the text of the monthly calendar days' date numbers, and then Google only interprets the last day (on mouse release) as a click to create a new event. It turns out that in this situation, region drag can work, but it's just very unreliable. It's unclear to me what causes this.

I thought it was Epiphany going into a "bad state" after a while or upon computer suspend/resume, but upon further testing I'm realizing now that this happens even on a fresh start, it was simply unreliable to begin with but I was just lucky with whatever sub-pixel position my mouse drag happened to start with.

I've tested this on both Epiphany 3.38.x and 41, on both the GNOME Xorg session and under the GNOME Wayland session, both as a web app and a regular GNOME Web browser window, with a traditional mouse or a trackpoint or touchpad. It occurs in all cases.