Dock icon not shown when run from within AppImage

[probonopd]

On Ubuntu 16.04:

me@host:~$ sudo strace -eopen -f ./qtquickapp-git.bacf740-x86-64.appimage 2>&1 | grep pix
[pid  3517] open("/tmp/.mount_9gxq2L/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 7
[pid  3517] open("/tmp/.mount_9gxq2L/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 7

Strangely, when we extract the AppImage and run it then, then it works:

me@host:~$ ./qtquickapp-git.bacf740-x86-64.appimage --appimage-extract
me@host:~$ sudo strace -eopen -f squashfs-root/AppRun 2>&1 | grep pix
[pid  3710] open("/home/me/squashfs-root/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 6
[pid  3710] open("/home/me/squashfs-root/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 6

I cannot currently explain this behaviour.

[crayxt]

Hi, it think it is an app icon, not tray icon? And I just tried Ubuntu 17.04 beta, and app icon appears just fine when run from appimage directly.

[probonopd]

Technically it is the icon of the window which we are setting here.

[probonopd]

@crayxt out of curiosity, do you get open() ... = 6 or = 7 when you run the above commands?

[crayxt]

@probonopd It is much stranger now, when the appimage in ~ directory, app icon does not show up, but when launched from ~/Downloads, then it does appear. strace gives 7 for both cases.

[crayxt]

I mean when you launch appimage from regular DE, there is nothing in tray area, that's why I pointed out that it is not a tray icon. Nevermind ;)

[probonopd]

Do you have appimaged running?

[crayxt]

Nope it is a live cd

[probonopd]

me@host:~$ ./qtquickapp-git.bacf740-x86-64.appimage --appimage-mount
/tmp/.mount_5DG5bM
me@host:~$ /tmp/.mount_5DG5bM/AppRun

DOES show the icon on ubuntu-16.04-desktop-amd64.iso whereas

me@host:~$ ./qtquickapp-git.bacf740-x86-64.appimage

does not.

[TheAssassin]

open() returns a file descriptor, and that's nothing but a simple integer.
See e.g. http://man7.org/linux/man-pages/man2/open.2.html for more information (or consult your local man 2 open).

I assume that the fd counter is increased whenever a new file is opened. That leads to the assumption that Qt internally opens one file less when it doesn't work.

[probonopd]

A fuller strace:

## Not working when running directly

root@host:/home/me# strace -eopen -f ./qtquickapp-git.bacf740-x86-64.appimage  2>&1 | grep pix -C 5
[pid 12208] open("/usr/share/X11/xkb/symbols/level3", O_RDONLY) = 7
[pid 12208] open("/usr/share/X11/xkb/symbols/level3", O_RDONLY) = 7
[pid 12208] open("/tmp/.mount_b7CyL4/usr/plugins/xcbglintegrations", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 7
[pid 12208] open("/tmp/.mount_b7CyL4/usr/plugins/xcbglintegrations/libqxcb-glx-integration.so", O_RDONLY|O_CLOEXEC) = 7
[pid 12208] open("/tmp/.mount_b7CyL4/usr/plugins/xcbglintegrations/libqxcb-glx-integration.so", O_RDONLY|O_CLOEXEC) = 7
[pid 12208] open("/tmp/.mount_b7CyL4/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 7
[pid 12208] open("/usr/share/mime/mime.cache", O_RDONLY|O_CLOEXEC) = 8
[pid 12208] open("/etc/localtime", O_RDONLY|O_CLOEXEC) = 9
[pid 12208] open("/usr/share/mime/types", O_RDONLY|O_CLOEXEC) = 9
[pid 12208] open("/usr/share/mime/image/png.xml", O_RDONLY|O_CLOEXEC) = 7
[pid 12208] open("/tmp/.mount_b7CyL4/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 7
[pid 12208] open("/tmp/.mount_b7CyL4/usr/plugins/imageformats", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 9
[pid 12208] open("/tmp/.mount_b7CyL4/usr/plugins/imageformats/libqgif.so", O_RDONLY|O_CLOEXEC) = 9
[pid 12208] open("/tmp/.mount_b7CyL4/usr/plugins/imageformats/libqico.so", O_RDONLY|O_CLOEXEC) = 9
[pid 12208] open("/tmp/.mount_b7CyL4/usr/plugins/imageformats/libqjpeg.so", O_RDONLY|O_CLOEXEC) = 9
[pid 12208] open("/tmp/.mount_b7CyL4/usr/plugins/imageformats/libqgif.so", O_RDONLY|O_CLOEXEC) = 9

## Working when running from mounted AppImage

root@host:/home/me# strace -eopen -f /tmp/.mount_5A4ecZ/AppRun 2>&1 | grep pix -C 5
[pid 12172] open("/usr/share/X11/xkb/symbols/level3", O_RDONLY) = 6
[pid 12172] open("/usr/share/X11/xkb/symbols/level3", O_RDONLY) = 6
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/plugins/xcbglintegrations", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 6
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/plugins/xcbglintegrations/libqxcb-glx-integration.so", O_RDONLY|O_CLOEXEC) = 6
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/plugins/xcbglintegrations/libqxcb-glx-integration.so", O_RDONLY|O_CLOEXEC) = 6
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 6
[pid 12172] open("/usr/share/mime/mime.cache", O_RDONLY|O_CLOEXEC) = 7
[pid 12172] open("/etc/localtime", O_RDONLY|O_CLOEXEC) = 8
[pid 12172] open("/usr/share/mime/types", O_RDONLY|O_CLOEXEC) = 8
[pid 12172] open("/usr/share/mime/image/png.xml", O_RDONLY|O_CLOEXEC) = 6
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 6
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/plugins/imageformats", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 8
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/plugins/imageformats/libqgif.so", O_RDONLY|O_CLOEXEC) = 8
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/plugins/imageformats/libqico.so", O_RDONLY|O_CLOEXEC) = 8
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/plugins/imageformats/libqjpeg.so", O_RDONLY|O_CLOEXEC) = 8
[pid 12172] open("/tmp/.mount_5A4ecZ/usr/plugins/imageformats/libqgif.so", O_RDONLY|O_CLOEXEC) = 8

[TheAssassin]

Both logs are equal, except for the mountpoint name (which we can ignore for now) and the return values of the open() calls. An interesting fact: They're all off by one, i.e. the working one's return values are -1.

[TheAssassin]

Just tested the file produced by Travis on my Xubuntu 16.04 desktop. In both cases, I can see QtQuickApp's icon in my task bar.
We should test this with other desktop environments, too, and see if we can narrow down the bug to Ubuntu's Unity DE.

[TheAssassin]

$ sudo strace -eopen -f ./QtQuickApp-git.bacf740-x86_64.AppImage   2>&1  | grep pix
[pid 25675] open("/tmp/.mount_8mwIOm/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 7
[pid 25675] open("/tmp/.mount_8mwIOm/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 7
[pid 25675] open("/usr/share/pixmaps/default/cursors/left_ptr", O_RDONLY) = -1 ENOENT (No such file or directory)

To sum up: I get the same return values for the open() calls, but the icon works perfectly fine.

[probonopd]

For what it is worth, it is working correctly from inside the AppImage on KDE neon User Edition 5.9:

me@host:~/Downloads$ sudo strace -eopen -f ./qtquickapp-git.bacf740-x86-64.appimage 2>&1  | grep pix
[pid  6152] open("/tmp/.mount_IY43lg/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 7
[pid  6152] open("/tmp/.mount_IY43lg/usr/share/pixmaps/qtquickapp.png", O_RDONLY|O_CLOEXEC) = 7

[probonopd]

So in summary, this may be related to Ubuntu Unity only. But why?

[probonopd]

@Phoerius reports here:

But we are also having similar issues with our Snap package which we haven't yet solved. I suppose this is a general problem with Ubuntu and self-contained app containers.

[probonopd]

Note to self: Try to set/unset XDG_DATA_DIRS.

[probonopd]

It also works on Ubuntu 14.04 GNOME Edition:

[Loxodromics]

In the latest version the icon works for me in virtual machines with Debian_8.6.0 (Gnome), openSUSE Tumbleweed (KDE) and Ubuntu 16.10 (Unity). But in no case does the icon show in the file manager – even after a restart.

[probonopd]

@Loxodromics the icon in the filemanager is not implemented for type 2 AppImages, see AppImage/AppImageKit#346

[Loxodromics]

@probonopd okay, I see, thank you

[probonopd]

@phoerious nailed it in
keepassxreboot/keepassxc#194 (comment)

I finally managed to fix this issue. It appears that Qt resolves icons also in the program's working directory, but Unity doesn't. So when Qt found the icon there, it passes it on to the tray which tries to resolve the path again, but can't find it. I fixed it by enforcing absolute icon paths for tray icons.

So, absoluteFilePath in this code

QFileInfo fi(app.applicationDirPath() + "/../share/pixmaps/qtquickapp.png");
QGuiApplication::setWindowIcon(QIcon(fi.absoluteFilePath()));

makes it work on Ubuntu Unity. Thanks @phoerious