Instead of 17 XFillPolygon() calls we now use 5.

Was wrong when scale was different from 1

It is not needed elsewhere.

They are not used from the outside.

was offset to the right and downwards before

Fixes ArcticaProject/nx-libs#892

The problem we are fixing (or better "working around") here has also
been seen in XQuartz, but no-one has found the reason yet.

Point to bugreport so that anyone stumbling over this in future can
check if there's a better fix and possibly implement that one.

Backport of this xorg-xserver commit:

  commit cfd3443fe81685e91a53063dee58e24a5684dc29
  Author: Peter Hutterer <peter.hutterer@who-t.net>
  Date:   Wed Jan 28 13:34:10 2009 +1000

    Xext: rename saver's EventType to SaverEventType.

    Avoid namespace clashing with the internal events.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

Backport of this xorg-xserver patch:

  commit 3083c5d0c4386cdd7083b7a83ac72fdad2f1e61e
  Author: Michel Dänzer <daenzer@vmware.com>
  Date:   Mon Mar 22 18:01:17 2010 +0100

    Xext: Fix cursor reference counting hazard.

    Make sure the reference count of the new cursor is increased before the old
    one is decreased, otherwise bad things will happen if they're one and the
    same and the reference count is 1 initially. Not sure this can actually happen
    here, but better safe than sorry.
Signed-off-by: Michel Dänzer <daenzer@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Signed-off-by: Keith Packard <keithp@keithp.com>

(from nxagent changelog)

It is better to create the values array once and not on every iteration..

Does not require two parameters. It could be replaced by
RegionDestroy() entirely but we leave it to have a match to
nxagentCreateRegion().

Now all cleanup code at the end of the function is gone so there's no
need for the gotos anymore. Just return directly.

move common code into helper function that also takes care of the ugly
alloc/free stuff.

Otherwise we will never be able to free the list because we do not know
if free() is allowed or not.

add else clauses, improve debugging, add comments

not a real memleak since it is followed by a FatalError...

The FIXME just described what the following function actually implements...

Attributes GH PR #922: https://github.com/ArcticaProject/nx-libs/pull/922

if neither NX_CLIENT ist provided nor /usr/NX/bin/nxclient is existing
try /usr/bin/nxdialog.

Currently the path is hardcoded.

Attributes GH PR #917: https://github.com/ArcticaProject/nx-libs/pull/917