Bug 1627823

Summary:	Strange scroll behavior in virt-manager
Product:	[Fedora] Fedora	Reporter:	User <bgzlla>
Component:	spice-gtk	Assignee:	Marc-Andre Lureau <marcandre.lureau>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	28	CC:	alon, berrange, cfergeau, crobinso, hdegoede, marcandre.lureau, sandmann, victortoso
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:	spice-gtk-0.35-3.fc29	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-10-02 19:28:28 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description User 2018-09-11 15:04:44 UTC

Description of problem:

After upgrading to F28, the first regression I noticed was that when using the mouse wheel inside a virtual machine, there is a sort of "buffer" in either direction that must be filled before it begins registering a scroll event. The buffer is 3 turns. 

For example, if I want to scroll down, it takes 3 downward turns before 1 turn is registered inside the virtual machine. From that point, any downward turn is registered. But if I then want to scroll up, it takes 3 upward turns before the turns begin to register. Scrolling up then works fine, but I must again scroll 3 times if I want to scroll downward.

I've tried using both Wayland and X on GNOME. A myriad of video settings (QXL/Spice/etc) in virt-manager. Upgrading the VMs to F28. Different mouses. No luck.

This critically destroys my workflow and I consider it a severe UI regression. Scrolling is messed up, some simple UI actions have become tedious.

Version-Release number of selected component (if applicable):
1.5.1

How reproducible:
Seems to be 100% reproducible.

Steps to Reproduce:
1. Upgrade to Fedora 28
2. Try to scroll with mouse wheel while using a virtual machine

Actual results:
Mouse wheel behavior seems to have a "dead zone" of 3 turns

Expected results:
Mouse wheel behavior mimics behavior

Additional info:

I'm not sure if virt-manager is to blame, but I'm just not sure what a better component would be. Feel free to change it.

Comment 1 Cole Robinson 2018-09-11 23:56:42 UTC

I reproduced, basically exactly what you describe, scroll doesn't move for me until the third click. But for me it's specific to spice graphics. I bisected spice-gtk and it seems to be this commit which entered Fedora with 0.35 version

commit 2212f05145c5f1d5734f0cb7d3945dc58c1d5c8c
Author: Marc-André Lureau <marcandre.lureau>
Date:   Thu Jun 7 19:32:09 2018 +0200

    widget: handle smooth-scroll events

Comment 2 User 2018-09-12 19:53:54 UTC

Very interesting. I had a suspicion it was related to Spice and came upon that very commit after searching release notes, but for some reason I thought that after switching to VNC the problem still presented itself. Testing again, it works fine now.

This seems like it will be an easy fix then, because if I remember correctly, that commit specifically deals with detecting smooth scroll events with touchpads on Wayland. It's likely a dev was just lazy and didn't correctly differentiate between events originating from a regular mouse and touchpad.

Comment 3 Christophe Fergeau 2018-09-13 09:44:44 UTC

(In reply to User from comment #2)
> It's likely a dev was just lazy and didn't
> correctly differentiate between events originating from a regular mouse and
> touchpad.

For what it's worth, this kind of comments is not particularly welcome..

Comment 4 User 2018-09-13 17:23:02 UTC

I apologize if that was inappropriate. I was just joking about the lazy bit, we all make mistakes when developing software and I appreciate all of the hard work that has gone into Spice.

Comment 5 Victor Toso 2018-09-14 12:48:14 UTC

Sent a possible fix [0] but not sure if that's great solution still. Feel free to give feedback based on scratch-build [1] below

[0] https://lists.freedesktop.org/archives/spice-devel/2018-September/045574.html
[1] https://koji.fedoraproject.org/koji/taskinfo?taskID=29669518

Comment 6 Fedora Update System 2018-09-21 12:06:02 UTC

spice-gtk-0.35-3.fc29 has been submitted as an update to Fedora 29. https://bodhi.fedoraproject.org/updates/FEDORA-2018-f2d2ea7fd9

Comment 7 Fedora Update System 2018-09-22 20:03:50 UTC

spice-gtk-0.35-3.fc29 has been pushed to the Fedora 29 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-f2d2ea7fd9

Comment 8 Fedora Update System 2018-10-02 19:28:28 UTC

spice-gtk-0.35-3.fc29 has been pushed to the Fedora 29 stable repository. If problems still persist, please make note of it in this bug report.