Unity menus aren't initially populated (xenial, bionic)

[Alistair Cunningham]

If you navigate using the mouse to a menu that has a submenu, for example View -> Toolbars, sometimes the first time you do so, the submenu is empty and only shows as a very small grey rectangle. If you then move the mouse pointer away from the menu, click in the middle of a web page, wait a few seconds, and then try the submenu again, the submenu is appears correctly.

Thunderbird 68.2.1 is also affected by this problem.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: firefox 70.0.1+build1-0ubuntu0.19.10.1
ProcVersionSignature: Ubuntu 5.3.0-23.25-generic 5.3.7
Uname: Linux 5.3.0-23-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
AddonCompatCheckDisabled: False
ApportVersion: 2.20.11-0ubuntu8.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: alistair 2189 F.... pulseaudio
BuildID: 20191031091608
Channel: Unavailable
CurrentDesktop: Unity:Unity7:ubuntu
Date: Mon Dec 2 10:31:01 2019
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
 dns-search integrics.com
IncompatibleExtensions:
 English (GB) Language Pack - <email address hidden>
 English (South Africa) Language Pack - <email address hidden>
 Default - {972ce4c6-7e08-4474-a285-3208198ce6fd}
InstallationDate: Installed on 2017-08-16 (837 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
IpRoute:
 default via 172.20.0.1 dev wlp58s0 proto dhcp metric 600
 169.254.0.0/16 dev wlp58s0 scope link metric 1000
 172.20.0.0/20 dev wlp58s0 proto kernel scope link src 172.20.0.120 metric 600
MostRecentCrashID: bp-3d145359-2f62-4b35-a046-86be50191125
PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/firefox/omni.ja:greprefs.js:930
PrefSources: prefs.js
Profiles: Profile0 (Default) - LastVersion=70.0.1/20191031091608 (In use)
RunningIncompatibleAddons: True
SourcePackage: firefox
UpgradeStatus: Upgraded to eoan on 2019-10-04 (58 days ago)
dmi.bios.date: 08/30/2019
dmi.bios.vendor: LENOVO
dmi.bios.version: N1WET56W (1.35 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20HFCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN1WET56W(1.35):bd08/30/2019:svnLENOVO:pn20HFCTO1WW:pvrThinkPadT470s:rvnLENOVO:rn20HFCTO1WW:rvrNotDefined:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad T470s
dmi.product.name: 20HFCTO1WW
dmi.product.sku: LENOVO_MT_20HF_BU_Think_FM_ThinkPad T470s
dmi.product.version: ThinkPad T470s
dmi.sys.vendor: LENOVO

[Alistair Cunningham (acunningham)]

Also reported for Thunderbird in bug 1854756.

[Olivier Tilloy (osomon)]

I'm seeing something slightly different to what you're describing in a xenial VM: submenus do open empty indeed, however after a fraction of a second they are redrawn with the correct menu entries.

Can you confirm that in your case you need to close the menu and re-open it again to make its content appear?

[Alistair Cunningham (acunningham)]

That's interesting. It sounds like there's a race condition that's affecting us differently. In my case, the submenus definitely aren't being populated, even if I hover the mouse pointer over the parent menu item for 30 seconds. If I then move the mouse pointer away and back again, only then is the submenu populated correctly.

[Alistair Cunningham (acunningham)]

Olivier, any news on this? It's still happening.

[c4pp4 (c4pp4)]

It's related to https://gitlab.gnome.org/GNOME/gtk/issues/1651

[c4pp4 (c4pp4)]

revert against gtk+3.0_3.24.12

[c4pp4 (c4pp4)]

The list of commits causing the issue #1651 from https://gitlab.gnome.org/GNOME/gtk/issues/1651
https://github.com/GNOME/gtk/commit/00486efd51b29e234cfb180b814dd584805ebae5
https://github.com/GNOME/gtk/commit/3e586a82e6cc563a84f7f16341c63743b0c62762
https://github.com/GNOME/gtk/commit/c35878ecf1e9ee960b72b213b73c15f92b64afe5

The list of commits fixing the issue 1651 and causing this issue (LP #1854753) related to firefox/thunderbird global/titlebar menu (debian/patches/unity-menubar.patch):
https://github.com/GNOME/gtk/commit/edb57a9202907ff6f54390bdc7ae02e42de87cfe
https://github.com/GNOME/gtk/commit/461f5fde0340137678416422a026c4369d5dcff8
https://github.com/GNOME/gtk/commit/7298e73c445dc06e9840c47667501e1cb5dd5a71
https://github.com/GNOME/gtk/commit/57300b49602b856b53f5d30ab3174591c0fb2845

[Alistair Cunningham (acunningham)]

This problem still happens on Ubuntu 20.04 beta. Is there any progress in fixing it?

[Olivier Tilloy (osomon)]

The patch to export the firefox/thunderbird menus to the global menu was removed in 20.04.
I expect 16.04 and 18.04 are still affected though, but I haven't had a chance to look into the problem further.