I'm on Plasma 5.12.3 in KDE Neon. If I activate Show Desktop (Meta-D on my setup), all windows are swiped to the corners (but not minimized). If I then click on a program in the task manager that is open, that window does not get focus. Instead, Show Desktop un-does itself, but leaves the last active window focused. A simple way to reproduce is as follows: 1. Open a program, let's say Firefox. Keep it non-minimized 2. Open a different program, let's say Dolphin. Keep this non-minimized 3. Give Dolphin focus 4. Hit Ctrl-F12 to show desktop 5. Now click on the Firefox icon in the task manager 6. Windows come back, Dolphin still has focus. There are some strange exceptions to this behavior: 1. If Dolphin is active, but Firefox is minimized, then when you click Firefox after showing desktop, Firefox *does* get focus (and un-minimizes). 2. If Dolphin is active and Firefox isn't open at all, just "pinned" to the task manager, then clicking Firefox opens the program and gives it focus. I've tried this with both the icons-only task manager and the regular one. This should be changed so that clicking a window gives it focus no matter what.
I put this as "general" for now as I wasn't sure if it should go to the Task Manager widget, or the Icons-Only Task Manager widget, or somewhere else. Please feel free to change.
Can reproduce the issue in: Plasma: 5.12.3 Apps: 17.12.3 Frameworks: 5.44.0 Qt: 5.10.1 Kernel: 4.14.27-1-MANJARO OS: Netrunner Rolling
The same behavior can be repdoduced with "minimize all windows" widget on neon dev unstable under X11.
Looks like this bug belongs to kwin and was introduced by a fix to bug 375993. When calling Workspace::activateClient(), Workspace::setShowingDesktop() is called and with the code from that fix added it ends up activating a wrong window.
*** Bug 419156 has been marked as a duplicate of this bug. ***
Can confirm. Would you like to submit a fix, Alexander?
This is fixed now.