Right click on grouped window missing for 4.14

Submitted by True Random

Assigned to Xfce Bug Triage

Created attachment 8909 correct behavior on xfce 4.12

With XFCE 4.12 it was possible to right click a single item for a grouped window.

How to reproduce?

Enable window grouping (panel-preferences > items > edit window buttons > window grouping: always)
open thunar (or any other program) 2 times
left click the stack inside the panel
a pop up opens showing the two thunar instances
right click one of them

actual behavior: right click is same as left click

expected behavior: another context menu opens e.g. for closing this instance

version: 4.14-Arch

See the attached screenshot for the correct behavior on xfce 4.12

Attachment 8909, "correct behavior on xfce 4.12":

Version: 4.14.0