Bug 574182

Summary:

[GTK3] Label: Incorrect image drawing with 200% zoom

Product:

[Eclipse Project] Platform

Reporter:

Thomas Singer <ts-swt>

Component:

SWT

Assignee:

Sravan Kumar Lakkimsetti <sravankumarl>

Status:

NEW ---

QA Contact:

Severity:

critical

Priority:

CC:

akurtakov, alexandr.miloslavskiy, sdamrong, sravankumarl, ts-swt

Version:

4.21

Target Milestone:

---

Hardware:

OS:

Linux

Whiteboard:

Attachments:

Description	Flags
Snippet to reproduce	none
Screenshot from Manjaro	none
Screenshot on Windows 10	none
Screenshot from Fedora 34 Wayland	none

Description Thomas Singer

2021-06-14 05:01:37 EDT

Please launch the attached snippet on Linux (tried Ubuntu 20.04 and latest Manjaro/Gnome). I expect to see a cyan image drawn where the whole background is filled. But on Linux I see a black image drawn where the left upper quarter is just cyan.

Comment 1 Thomas Singer

2021-06-14 05:02:18 EDT

Created attachment 286590 [details]
Snippet to reproduce

Comment 2 Thomas Singer

2021-06-14 05:02:45 EDT

Created attachment 286591 [details]
Screenshot from Manjaro

Comment 3 Thomas Singer

2021-06-14 05:03:56 EDT

Created attachment 286592 [details]
Screenshot on Windows 10

Comment 4 Sravan Kumar Lakkimsetti

2021-06-16 02:46:42 EDT

I can reproduce this problem. I am investigating.

Comment 5 Sravan Kumar Lakkimsetti

2021-06-16 05:55:30 EDT

@paul, 

Can you please check whether you can reproduce this on RHEL/fedora/centos?

This is reproducible on Ubuntu. My feeling is some thing wrong with cairo libraries on Ubuntu.

Comment 6 Soraphol (Paul) Damrongpiriyapong

2021-06-29 16:32:14 EDT

Created attachment 286703 [details]
Screenshot from Fedora 34 Wayland

@Sravan

Sorry for the late reply. 

On Fedora 34 Wayland with scale set to 200% in the Displays setting, I don't experience the black rectangle around the cyan. Attached is a screenshot.

Comment 7 Sravan Kumar Lakkimsetti

2021-07-01 08:43:52 EDT

(In reply to Soraphol (Paul) Damrongpiriyapong from comment #6)
> Created attachment 286703 [details]
> Screenshot from Fedora 34 Wayland
> 
> @Sravan
> 
> Sorry for the late reply. 
> 
> On Fedora 34 Wayland with scale set to 200% in the Displays setting, I don't
> experience the black rectangle around the cyan. Attached is a screenshot.

That means its a problem with Ubuntu only.

Comment 8 Thomas Singer

2021-07-01 09:24:06 EDT

> That means its a problem with Ubuntu only.

It happens for Manjaro, too. But we need to use GDK_BACKEND=x11 to work around some other GTK bugs I have forgotten.

Comment 9 Alexander Kurtakov

2021-08-17 14:16:27 EDT

What are the wayland bug you workaround by falling back to x11?

Comment 10 Thomas Singer

2021-08-19 08:59:07 EDT

I don't know any more and haven't recorded it in our launcher script. I will remove the lines

if [ "$XDG_SESSION_TYPE" = "wayland" ]; then
	export GDK_BACKEND=x11
fi

and let you know what problems occur.