The existing code was difficult to follow, it contained some code
duplication, inconsistencies and legacy code (mwm/dtwm support).
Most of this code was copied over from Qt 4 as is, with some
unexplainable (accidental?) modifications.
Most of Motif code was never ported over to Qt5. In addition to the
properties and protocols described in ICCCM, Motif uses properties
and protocols of its own. In Qt4 we had an implementation of Motif
DnD protocol. This was never ported over and mentions of this support
was removed on Oct 2012, 4c41cb48d0.
Nobody has complained for all these years, so it is safe to remove
the remaining leftovers. Motif style support also was removed around
the same time 4c41cb48d0.
Keeping only those Motif hints that do not have any replacement in
modern window manager specifications - decorations hints.
MWM_INPUT_*MODEL* in modern specs was replaced by _NET_WM_STATE_MODAL
The existing code was setting _MOTIF_WM_HINTS from 2 places - from
QWindow setter (::setWindowFlags) and again before mapping the window
(::show). We don't need the logic from updateMotifWmHintsBeforeMap().
That function read the current value of _MOTIF_WM_HINTS and merged in
few additional hints, hints that are not relevant based on all the
reasons from above.
Change-Id: I9cb10bcad9bfac8762e3909895c2e9de613e622c
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
b4bd5f9df3