resizing loop on high-dpi screen

[Andreas E.]

When the global scaling factor is set to 2, some dialogs occasionally start changing their window size causing very high CPU activity.

This occurs for example in dconf-editor while searching: It appears dconf-editor tries to adjust the window dimensions to the size of the content and reduces the window size until it is unusable. This causes very high CPU activity and freezes the window content.
It also happens when (then) resizing the window width (→) or height (↓) afterwards, it tries to revert to the previous window size. However, the only way to resize the window back so that it doesn't reduce its size is by dragging the window corner (↓→).

This issue happens also in other applications, for example in apport-dialogs when expanding the collapsed details view.

This does not happen when the global scaling factor is set to 1. It could be related to the new window resizing method that updates the window content.

org.gnome.desktop.interface.scaling-factor = 2

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.1.2+14.04.20140321-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-17.37-generic 3.13.6
Uname: Linux 3.13.0-17-generic x86_64
ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Fri Mar 28 16:07:47 2014
EcryptfsInUse: Yes
InstallationDate: Installed on 2014-02-02 (53 days ago)
InstallationMedia: Ubuntu-GNOME 14.04 "Trusty Tahr" - Alpha amd64 (20140201)
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)

[Andreas E. (andreas-e)]

Does nobody else see this issue??
It happens in quite many applications: apport-gtk, bluetooth configuration, gnome-sudoku, dconf-editor, control center / input methods, a couple of file save dialogs.
It happens on a new user account as well, so I assume it is not caused by any configuration files.

[Andreas E. (andreas-e)]

Does nobody else experience this, or does nobody else have a high resolution device for being able to experience it?

I get this issue also in the daily utopic unicorn (28.7.) with Unity 7.3.
I believe it is due to some flexible box gtk component, but I don't have enough technical knowledge for a better guess.

[Andreas E. (andreas-e)]

This does still occurs frequently in Ubuntu 14.10 official release with Unity 7.3.1+14.10.20141016-0ubuntu1.

Some application windows freeze and "shrink" slowly for 10-30 seconds while turning the cpu up to 100%. When these windows have reached the smallest possible size, they remain unusable. When trying to resize them to a usable size, they continue freezing and shrinking.

[Launchpad Janitor (janitor)]

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

[Stephen M. Webb (bregma)]

I get this every time I click on the "show details" button of the "application has crashed" dialog that pops up when I log in. If you need an example.

[Stephen M. Webb (bregma)]

Oh, and my scaling is set to 1.88, so it's not related to the GTK scaling >= 2 problems.