Scaling is not reverted properly (appears shrunk) when disabling fractional scaling

[Iain Lane]

* Impact

Scaling is not reverted properly (appears shrunk) when disabling fractional scaling

* Test Case

Do this in an Ubuntu/Xorg session:

0. Be on a "clean" system wrt. fractional scaling, i.e. disabled & scaling at 100%
1. Open gnome-control-center → displays
2. Turn on fractional scaling
3. Select 125%
4. Press apply (the scaling should correctly change now)
5. Turn off fractional scaling by changing the toggle

Now everything is shrunk - it's not been returned to 100% properly. See the attached screenshot where the text is tiny instead of regular 100% size. If you do this instead of step 5:

5. Select 100% scaling
7. Press apply
8. Turn off fractional scaling by changing the toggle

Then everything returns to the normal size.

Repeat the same selecting 200% at 5., (or 100% if 200% was your default) and ensure it's applied.

I'm on nvidia(-440), but Séb said that he saw this on his Intel machine too.

* Regression potential

Verify that scaling changes are correctly applied on different setup

ProblemType: BugDistroRelease: Ubuntu 20.04
Package: mutter 3.36.1-3ubuntu3
ProcVersionSignature: Ubuntu 5.4.0-28.32-generic 5.4.30
Uname: Linux 5.4.0-28-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: GNOME
Date: Tue May 5 10:57:40 2020
InstallationDate: Installed on 2012-10-07 (2766 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Beta amd64 (20121007)SourcePackage: mutter
UpgradeStatus: Upgraded to focal on 2020-01-16 (109 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Wilfred (wxwee)]

Can we set the importance on this bug as 'High' since bug 1873403 relies on this and that bug is High?

[Launchpad Janitor (janitor)]

This bug was fixed in the package gnome-control-center - 1:3.36.3-1ubuntu1

---------------
gnome-control-center (1:3.36.3-1ubuntu1) groovy; urgency=medium

  * New upstream version rebased on Debian (lp: #1884063)

  [ Gunnar Hjalmarsson ]
  * debian/patches/0030-temporarily-revert-alt-char-key.patch:
    - Change po/POTFILES.in too, so dh_translations can create
      gnome-control-center-2.0.pot.
  * d/p/0015-connectivity-add-network-connectivity-checking-toggl.patch:
    - Add "privacy" to Keywords in the .desktop file in line with
      https://gitlab.gnome.org/GNOME/gnome-control-center/-/commit/05f3cb67
      (LP: #1869288)

  [ Marco Trevisan (Treviño) ]
  * d/p/0008-Allow-tweaking-some-settings-for-Ubuntu-Dock.patch:
    - Ensure dock position is respected in RTL (LP: #1876937)
    - Add proper matching the dock monitor ID (LP: #1877108)
  * d/p/0024-display-Allow-fractional-scaling-to-be-enabled.patch:
    - Improve fractional scaling toggling (LP: #1876891, #1876894)
    - Look for proper fractional scaling key in Wayland and X11 (LP: #1871864)
  * d/p/0031-fingerprint-dialog-Don-t-limit-the-number-of-maximum.patch:
    - Don't make flowbox children selectable (LP: #1877441)

 -- Sebastien Bacher <email address hidden> Thu, 18 Jun 2020 13:44:56 +0200

[Brian Murray (brian-murray)]

Hello Iain, or anyone else affected,

Accepted gnome-control-center into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/gnome-control-center/1:3.36.3-0ubuntu1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Sebastien Bacher (seb128)]

Testing 1:3.36.3-0ubuntu1 there is no scaling to a tiny ration, marking as verified

[Launchpad Janitor (janitor)]

This bug was fixed in the package mutter - 3.36.3-1ubuntu2

---------------
mutter (3.36.3-1ubuntu2) groovy; urgency=medium

  * debian/control:
    - Revert BD on adwaita-icon-theme 3.36.1-2ubuntu3. It was just temporary fix.
  * d/p/x11-Add-support-for-fractional-scaling-using-Randr.patch:
    - Use pre-computed CRTC layout size for computing screen size (LP: #1874567,
      LP: #1873403)
    - Decouple the output mode from layout mode capabilities (LP: #1876894,
      LP: #1886996)
    - Ensure we notify CRTC changes on integer scaling changes (LP: #1876894)
    - Apply proper layout monitor config when using fractional scaling
      (LP: #1884754)
    - Restore the fractional settings when reverting to fractional layout
      (LP: #1886996)
  * debian/libmutter-6-0.symbols: Add new private symbol

 -- Marco Trevisan (Treviño) <email address hidden> Sat, 11 Jul 2020 00:44:33 +0200

[Launchpad Janitor (janitor)]

This bug was fixed in the package gnome-control-center - 1:3.36.3-0ubuntu1

---------------
gnome-control-center (1:3.36.3-0ubuntu1) focal; urgency=medium

  * New stable version (lp: #1884063)

  [ Gunnar Hjalmarsson ]
  * debian/patches/0030-temporarily-revert-alt-char-key.patch:
    - Change po/POTFILES.in too, so dh_translations can create
      gnome-control-center-2.0.pot.

  [ Marco Trevisan (Treviño) ]
  * d/p/0008-Allow-tweaking-some-settings-for-Ubuntu-Dock.patch:
    - Ensure dock position is respected in RTL (LP: #1876937)
    - Add proper matching the dock monitor ID (LP: #1877108)
  * d/p/0024-display-Allow-fractional-scaling-to-be-enabled.patch:
    - Improve fractional scaling toggling (LP: #1876891, #1876894)
    - Look for proper fractional scaling key in Wayland and X11 (LP: #1871864)
  * d/p/0031-fingerprint-dialog-Don-t-limit-the-number-of-maximum.patch:
    - Don't make flowbox children selectable (LP: #1877441)

 -- Sebastien Bacher <email address hidden> Tue, 23 Jun 2020 17:50:27 +0200

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for gnome-control-center has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Brian Murray (brian-murray)]

Hello Iain, or anyone else affected,

Accepted mutter into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/mutter/3.36.4-0ubuntu0.20.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Łukasz Zemczak (sil2100)]

Hello Iain, or anyone else affected,

Accepted mutter into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/mutter/3.36.4-0ubuntu0.20.04.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Marco Trevisan (Treviño) (3v1n0)]

Reverting to both 100% and 200% works fine, without issues. g-c-c now requires a further "apply" to turn it off, and mutter reacts properly when setting it back to both 200% and 100%.

marco-ThinkPad-X1-Carbon-7th ~ 13:22:00
❯ apt-cache policy libmutter-6-0
libmutter-6-0:
  Installed: 3.36.4-0ubuntu0.20.04.2
  Candidate: 3.36.4-0ubuntu0.20.04.2
  Version table:
 *** 3.36.4-0ubuntu0.20.04.2 500
        500 http://it.archive.ubuntu.com/ubuntu focal-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     3.36.3-0ubuntu0.20.04.1 500
        500 http://it.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
     3.36.1-3ubuntu3 500
        500 http://it.archive.ubuntu.com/ubuntu focal/main amd64 Packages

marco-ThinkPad-X1-Carbon-7th ~ 13:22:02
❯ apt-cache policy gnome-control-center
gnome-control-center:
  Installed: 1:3.36.4-0ubuntu1
  Candidate: 1:3.36.4-0ubuntu1
  Version table:
 *** 1:3.36.4-0ubuntu1 500
        500 http://it.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1:3.36.1-1ubuntu5 500
        500 http://it.archive.ubuntu.com/ubuntu focal/main amd64 Packages

[Launchpad Janitor (janitor)]

This bug was fixed in the package mutter - 3.36.4-0ubuntu0.20.04.2

---------------
mutter (3.36.4-0ubuntu0.20.04.2) focal; urgency=medium

  * xrandr-scaling: Never try to set invalid screen sizes (LP: #1889090)

mutter (3.36.4-0ubuntu0.20.04.1) focal; urgency=medium

  * New upstream stable release (LP: #1887998)
    - Fix crash on area screenshots with fractional scaling
    - Do not paint textures of fully obscured windows
    - Turn off CRTCs as well when enabling DPMS
    - Improve selection support
    - Use a more appropriate combine function on opaque areas
    - Fix remote desktop being broken without screencast session
    - Fix popovers disappearing on wayland and HiDPI
    - Fixed crashes (LP: #1870867, LP: #1857947)
    - Plugged memory leaks
  * d/p/screen-cast-Let-the-reason-for-recording-determine-what-t.patch,
    d/p/screen-cast-src-Add-flag-to-maybe_record.patch,
    d/p/screen-cast-src-Fix-signedness-of-timestamp-field.patch,
    d/p/screen-cast-src-Make-record-functions-return-an-error-whe.patch,
    d/p/screen-cast-src-Make-the-two-record-vfuncs-more-similarly.patch,
    d/p/screen-cast-src-Record-follow-up-frame-after-timeout.patch,
    d/p/screen-cast-src-Remove-follow-up-timeout-source-on-disabl.patch,
    d/p/screen-cast-src-Use-G_USEC_PER_SEC-instead-of-1000000.patch,
    d/p/screen-cast-window-stream-src-Fix-indentation.patch:
    - Import more fixes for screencasting and remote desktop
  * d/p/x11-Add-support-for-fractional-scaling-using-Randr.patch:
    - Don't export patch-only private symbol
  * debian/libmutter-6-0.symbols:
    - Remove ubuntu-only private symbol

mutter (3.36.3-0ubuntu0.20.04.2) focal; urgency=medium

  * debian/control:
    - Revert BD on adwaita-icon-theme 3.36.1-2ubuntu3. It was just temporary fix
  * d/p/x11-Add-support-for-fractional-scaling-using-Randr.patch:
    - Use pre-computed CRTC layout size for computing screen size (LP: #1874567,
      LP: #1873403)
    - Decouple the output mode from layout mode capabilities (LP: #1876894,
      LP: #1886996)
    - Ensure we notify CRTC changes on integer scaling changes (LP: #1876894)
    - Apply proper layout monitor config when using fractional scaling
      (LP: #1884754)
    - Restore the fractional settings when reverting to fractional layout
      (LP: #1886996)
  * debian/libmutter-6-0.symbols: Add new private symbol

 -- Marco Trevisan (Treviño) <email address hidden> Mon, 27 Jul 2020 17:04:41 +0200