Bug 99088

Summary:	In Wayland, Endless Sky game's window drawn in the wrong place when alt-tabbing away and back again
Product:	Wayland	Reporter:	Nate Graham <nate>
Component:	wayland	Assignee:	Wayland bug list <wayland-bugs>
Status:	RESOLVED INVALID	QA Contact:
Severity:	normal
Priority:	medium	CC:	mcatanzaro, nate
Version:	1.5.0
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Nate Graham 2016-12-15 04:27:21 UTC

Fedora 25 + GNOME 3.22 + Wayland

A graphical anomaly is seen with the SDL-based video game Endless Sky on Fedora 25 with Wayland. When the game is being played full-screen, alt-tabbing away and back again results in the game's window being drawn in the wrong location: offset down and to the right. Here is a screen recording indicating the problem:

http://hommelscitadel.com/wp-content/uploads/2016/12/not_quite_right.webm

The issue is 100% reproducible with Wayland every way I try, but not seen if I log into an X session and try the same thing, so Wayland is clearly the culprit--or the way SDL or this game is interacting with it.


Note: Endless Sky is not available in any repos, but can be compiled and run thusly:

$ git clone https://github.com/endless-sky/endless-sky.git
$ sudo dnf install gcc-c++ scons SDL2-devel libpng-devel libjpeg-turbo-devel mesa-libGL-devel sglew-devel openal-soft-devel libmad-devel
$ cd endless-sky
$ scons
$ ./endless-sky

Comment 1 Nate Graham 2016-12-15 05:34:38 UTC

Hardware: Kaby Lake (late 2016) HP Spectre x360 laptop, Intel HD 620 integrated graphics card, 13.3" display, Kernel 4.8.13 (though this has happened since 4.8).

Comment 2 Michael Catanzaro 2017-01-07 19:00:02 UTC

Hi, this is the bug tracker for Wayland protocol issues. Nobody is going to fix your issue here. This is most likely a bug in GNOME Shell I would guess, so you could report it on GNOME Bugzilla, but it might be better to start on the Endless Sky bugtracker as GNOME folks would be much more likely to look at it if the game developers are involved.

Comment 3 Nate Graham 2017-01-07 19:18:18 UTC

I did report it on the Endless Sky issue tracker first: https://github.com/endless-sky/endless-sky/issues/1902

The developer said it was probably an issue with SDK or Wayland itself. So I filed a bug here. I'd rather not go on a huge wild goose chase so how can we determine whose problem it is? Again, this issue manifests in a Wayland session, but not with Xorg.

Comment 4 Michael Catanzaro 2017-01-07 19:49:47 UTC

It's either a bug in Endless Sky, or in GNOME Shell, or maybe in mutter. No clue which. Since you've already got a bug report against Endless Sky, the next step is surely GNOME Bugzilla.

Comment 5 Nate Graham 2017-01-07 20:08:59 UTC

Gotcha, thanks!

GNOME bug:https://bugzilla.gnome.org/show_bug.cgi?id=776992
SDL bug: https://bugzilla.libsdl.org/show_bug.cgi?id=3548

Comment 6 Michael Catanzaro 2017-01-07 22:49:18 UTC

So I am actually a GNOME developer, not a Wayland developer; I just happened to be passing through here. The reason I say it's not a "Wayland" bug, even though it clearly is, is that the Wayland repo is just a couple little libraries wrapping the Wayland protocol. All the bugs you find are probably going to be in either the toolkit (usually GTK+ or Qt, in this case SDL) or else compositor (GNOME) implementations. So when you find bugs running in Wayland on GNOME, report them to GNOME. Or if you're running in some other desktop, say KDE, then report them to KDE. Etc. This bug tracker is only useful if you're a developer and have found some protocol limitation. It's a shame nobody seems to have been watching it to give you a pointer to the right Bugzilla; this issue is obviously misplaced and should have been closed right away!

Comment 7 Nate Graham 2017-01-08 00:51:22 UTC

Thanks for the clarification. As you can see, I'm a bit new to this process and still learning how the whole technical infrastructure works (Apple background).

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