On Fri, Apr 30, 2021 at 10:23 AM Hans de Goede <hdegoede(a)redhat.com> wrote:
Hi,
On 4/30/21 3:33 PM, Vitaly Zaitsev via devel wrote:
> On 30.04.2021 12:23, Germano Massullo wrote:
>> There are many Fedora GNOME Wayland users experiencing quirks in using
KeepassXC. Textboxes not showing text that is being written, other quirks with GNOME,
etc.
>
> There are a lot of issues with Mutter and Qt5[1]. That's why the Qt upstream
forces XCB backend for the Gnome 3, but Fedora removes it in downstream[2], as approved by
the system-wide proposal[3].
>
> Please try the following:
> QT_QPA_PLATFORM=xcb /usr/bin/keepassxc
Ah interesting, I use calibre regularly under a GNOME3 wayland sessions and
I have noticed some weird issues there too, like the "completion" pop-ups
for things like the Author and Series fields which allow you to select an
Author / Series already used for other books showing up in completely
the wrong places, as well as right-click context(sub)menus also showing up
in completely the wrong places too.
I also use the audacious media-player for music in its x11amp compatible
skinned mode and that is has serious issues when used without
QT_QPA_PLATFORM=xcb under GNOME3. I thought this was just a special case
because of the skinned UI, but I now see that it is part of a wider pattern.
I was going to write the following here:
"""
I can understand if the KDE SIG wants to use Wayland by default when running
a KDE Wayland session, but under GNOME3 this indeed seems like a bad idea for now.
Maybe instead the QT_QPA_PLATFORM environment option can be set in the
KDE wayland session, so that Wayland is used there while leaving GNOME3
alone ?
"""
Which seems like a reasonable compromise to me, but then I looked at the
patch from [2] and it seems that that is the upstream default and the
Fedora packages are actually overriding this sensible upstream default.
> I think this downstream patch should be dropped from Fedora.
I tend to agree, it seems this downstream patch breaks at least 3 apps:
1. KeepassXC
2. calibre
3. audacious
And I have a feeling it breaks all Qt apps to at least some extend, now the
changes process page [3] does list a couple of reasons why this is necessary,
but I just checked and calibre looks fine with the mutter provided window
decorations for X11 windows instead of using CSD, so this does not seem like
a strong argument.
I can understand that it is desirable to make this change, but it seems that
QT5 just is not completely ready for this yet. For me the patch[2] breaks
2/2 Qt apps which I regularly used, so it seems that it would be best to drop
this downstream modification for now.
Note it only looks fine as long as you're not using fractional
scaling. Once framebuffer/fractional scaling is enabled in Mutter, it
looks absolutely terrible, because X11 applications are not scaled
properly. There are also other glitches if Qt5 applications run as X11
apps, and I'm not sure if some prominent Qt5 applications expose the
correct functionality in X11 mode (e.g. OBS Studio uses PipeWire for
screencasting when it is in Wayland mode).
In general, I'd like to see if we can figure out *why* Mutter isn't
doing the right thing for Qt applications and why they're breaking
this way, because the fact that they're fine in Plasma Wayland and not
on GNOME Wayland points to Mutter needing work here.
--
真実はいつも一つ!/ Always, there's only one truth!