SUMMARY
When opening a file in a new window in Nedit the new window is not activated


STEPS TO REPRODUCE
1. Install/build Nedit 5.7
2. Start Nedit
3. Disable tabbed editing (Preferences -> Default preferences -> Tabbed editing -> Disable "Open file in New tab")
4. Open "Open file" dialog (ctrl-O)
5. Select any file to open
6. [enter]

Other Motif applications that open new windows based on a Open File dialog may exhibit the same problem.

OBSERVED RESULT
The Open File dialog disappears, the original nedit window is activated, and the window with the new file is not activated or brought to top. Sometimes it is even hidden behind other windows.

EXPECTED RESULT
The new editing window should be activated and brought to top.

SOFTWARE/OS VERSIONS
OpenSUSE Leap 15.0
KDE Plasma Version: 5.12.6 ?
KDE Frameworks Version: 5.45.0
Qt Version: 5.9.4

ADDITIONAL INFORMATION
When pressing [enter] in file dialog Nedit unmaps the file dialog and then creates a new window. I suspect that kwin tries to activate the original edit window and cannot handle that a new window (even from the same application) is created+mapped while doing that. Changing "focus stealing prevention" to "none" has no effect.

This problem did not exist with kwin-4.11.2