Bug 257368 – [GTK] WebView content keeps disappearing on Rawhide (Evolution 3.48.1, webkit 2.41.3)

• Component: WebKitGTK
• Status: RESOLVED FIXED

[Milan Crha]

This is reported downstream at:
https://bugzilla.redhat.com/show_bug.cgi?id=2192408
More info can be found there.

On current Fedora Rawhide, with evolution-3.48.1-1.fc39.x86_64 and webkit2gtk4.1-2.41.3-1.fc39.x86_64 , the content of the preview pane often suddenly disappears. It still reacts as if it's there - if you blindly click on a link it will open - but you can't see it. Clicking anywhere in the preview pane after this happens brings it back, so it's not fatal, just annoying.

Steps to reproduce reliably, which worked at least for me, within Evolution:
a) select a different message to be viewed - it's shown in the preview panel below the message list
b) right-click the selected folder in the folder tree on the left and pick Properties
c) click three times on a checkbox "Copy for offline use" (I have the folder set to do the copy)
d) click the Close button - the mouse cursor is now roughly in the middle of the preview panel,
   which still shows the message content
e) move mouse cursor away from the web view - I usually move it to the top,
   but to the left worked as well

As soon as the mouse moves away from the web view the web view turns into grey. The items inside are still there, I can move the cursor abot the scrollbar and it suddenly appears. If the page has any buttons (like when there's an attachent), the buttons are shown too after moveing above them. This does not apply to the links. When I click to the message body, like if I'd like to focus the web view, the whole page redraws and everything is fine again.

All the steps are needed here, skipping any of them does not reproduce the problem. Even the a), selecting a new message to be viewed, is required.

It happens also when I run Evolution as:

   WEBKIT_DISABLE_DMABUF_RENDERER=1 evolution

I run the rawhide in a virtual machine. There is this printed after the evolution start:

   libEGL warning: pci id for fd 16: 1b36:0100, driver (null)

I do not know whether it's related. I saw different libEGL notices in the virtual machines, but none have any visible impact. This warning is shown shortly after start, before the bug exhibits.

[Adam Williamson]

Just to be clear on the reproducer steps - those are steps Milan found which *reliably* trigger the problem. But you don't need to do anything that complex to encounter it - it happens to me constantly just while I'm using my system normally. This isn't an obscure problem that can only be triggered by a complex series of actions.

[Michael Catanzaro]

Is this still happening with 2.41.90?

[Adam Williamson]

2.41.90 doesn't seem to be built for Fedora yet.

[Milan Crha]

For what it's worth, running:

   /usr/libexec/webkit2gtk-4.1/MiniBrowser https://yahoo.uservoice.com/forums/382977

from webkit2gtk4.1-2.40.5-1.fc38.x86_64 under GNOME Wayland shows an empty page, which can be scrolled up/down, thus the content is there, only not visible.

None of the WEBKIT_DISABLE_DMABUF_RENDERER=1, WEBKIT_DISABLE_COMPOSITING_MODE=1 nor WEBKIT_DISABLE_SANDBOX_THIS_IS_DANGEROUS=1 helps.

I tried also GNOME on X.org and it also doesn't pain the page content, the only difference is that the MiniBrowser prints on the console:

   libEGL warning: DRI2: failed to authenticate

Using webkit2gtk4.1-2.41.91-3.fc40.x86_64 the MiniBrowser shows the page content, but it also prints a lot more warnings on the console:

   /usr/libexec/webkit2gtk-4.1/MiniBrowser https://yahoo.uservoice.com/forums/382977
   libEGL warning: failed to get driver name for fd 0

   libEGL warning: MESA-LOADER: failed to retrieve device information

   libEGL warning: failed to get driver name for fd 0

   libEGL warning: egl: failed to create dri2 screen

The above is printed for the Wayland session, while the X.org session shows only these two lines:

   libEGL warning: DRI2: failed to authenticate
   libEGL warning: egl: failed to create dri2 screen

[Michael Catanzaro]

(In reply to Milan Crha from comment #4)
> Using webkit2gtk4.1-2.41.91-3.fc40.x86_64 the MiniBrowser shows the page
> content, but it also prints a lot more warnings on the console:

So this bug is fixed then, right? Can we close it?

All the warnings are bugs too, which should of course be fixed, but if the web content is not disappearing they are not this bug.

[Milan Crha]

It's fixed for the page I discovered misbehaves for me. I've not been able to reproduce the problem with pages/mails the other users faced the problem with. I'd say it's 50:50 fixed in the latest development version of the WebKitGTK.

[Michael Catanzaro]

Well, you reported this bug, so it's fixed.

If other users are still having trouble, they'll need to report it here. We can't play telephone game with graphics bugs. :)

[Adam Williamson]

It's me, hi.

I reported the bug, and I'm still here. :P

It's still happening in current F39, for me, with 2.41.91-2.fc39.

[Michael Catanzaro]

Sorry for missing this. Please do check if it's still happening with 2.44.0. If so, I'll reopen.

[Adam Williamson]

Nah, it's all good now. Don't recall when this got fixed, but it did.

[Xi Ruoyao]

It's not happening with 2.44.0 (at least to me).