Super+s accelerator key not activate with Mate 1.18 indicator applet menu

[Attila Hammer]

Dear developers,

I would like congratulate the Mate GTK3 migrated 1.18 version, this is a fantastic release.
I founded a bug with Mate Indicator Applet GTK3 version related:
Oldest Mate versions when I pressed the Super+s keystroke, right activated the indicator applet menu system when the Mate Indicator Applet compiled with GTK2 toolkit.
I now installed Ubuntu 17.04 development version from the Mate Edition ISO file.
Everithing is working right me virtual machine, except the indicator applet, with I unable to activate with the old Super+s accelerator key only with keyboard.
I using Ubuntu system only with screen reader and keyboard.

This is an important bug with Orca screen reader users when using the GTK3 migrated Mate 1.18 release. I tryed screen reader supported various techniques when I llocated the Indicator applet in my bottom panel (simulate a left mouse click in the applet, press space key the applet, press context menu button my keyboard, but the indicator menu system unfortunatelly doesn't present my screen.
Visually impaired users doesn't use the mouse, only using any desktop environment with keyboard if entire doesn't see the screen.

Reproducation steps, if you would like testing this bug:
1. Launch Orca screen reader, for example with orca --replace command, if you would like using only temporary the screen reader.
2. Click for example the bottom panel.
3. Click "add to panel..." menu item, and choose the complete indicator applet.
4. Try activating indicator applet with SUPER+S, or any supported accelerator key combination with previous GTK2 port Mate indicator applet supported.
Expected result:
When using for example with SUPER+S accelerator key combination, need presenting the indicator menu system, independent you have the panel, or any Mate application.

Actual result:
If I press the SUPER+S keystroke, nothing happening.

Attila

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: mate-indicator-applet 1.18.0-0ubuntu1
ProcVersionSignature: Ubuntu 4.10.0-11.13-generic 4.10.1
Uname: Linux 4.10.0-11-generic i686
ApportVersion: 2.20.4-0ubuntu2
Architecture: i386
CurrentDesktop: MATE
Date: Thu Mar 16 08:33:39 2017
InstallationDate: Installed on 2017-03-16 (0 days ago)
InstallationMedia: Ubuntu-MATE 17.04 "Zesty Zapus" - Alpha i386 (20170316)
SourcePackage: mate-indicator-applet
UpgradeStatus: No upgrade log present (probably fresh install)

[Attila Hammer (hammera)]

Unfortunatelly latest Ubuntu Mate development release affected too this issue related.
I now installed with Ubuntu Mate Bionic code named development release my KVM virtual machine.

[Launchpad Janitor (janitor)]

[Expired for mate-indicator-applet (Ubuntu) because there has been no activity for 60 days.]