Since a few months, pressing the tab key in LibreOffice Calc produces an unexpected (and highly annoying) behavior if LibreOffice has been installed with the kde USE flag enabled and Calc is run from a Plasma X session.
In the situation described above, pressing the tab key moves the cursor by one cell to the right, but it doesn't allow me to write into the cell: to do so, I have to press the tab key once again. It seems that pressing the tab key the first time gives focus to the menu bar because if, after pressing tab the first time I press one of the keys corresponding to the menu accelerators, that menu is shown (that is, if I press F the file menu is shown, if I press E the edit menu is shown and so on).
I tried installing LibreOffice using several combinations of the kde, gtk and gtk2 USE flags and it seems that the only way of stopping this behavior is to disable the kde flag. Running Calc from an Enlightenment or fvwm X session doesn't cause this issue. Running it from a Plasma session and replacing KWin wih the fvwm window manager using fvwm --replace doesn't stop it. Running plasmashell from a fvwm session doesn't cause the issue to appear.
I'm running libreoffice with USE="bluetooth branding cups dbus gstreamer gtk java kde ldap mariadb" and "UI render: GL; VCL: gtk3;" without those symptoms.
But I now realize that the gtk3 there is something I set myself over a year ago in /etc/env.d/99local ...
"VCL: kde5;" (SAL_USE_VCLPLUGIN="kde5" in the environment) does indeed cause the described symptoms here too.
Confirmed, but the good news is it seems to be fixed already in the upcoming release.
188.8.131.52 was added to tree as a pre-release without keywords.