Backport of this commit:

  commit 7ba7085b4f01f3cd72008712a5333ea3f0edfd88
  Author: walter harms <wharms@bfs.de>
  Date:   Sat Oct 28 19:14:22 2017 +0200

    AuRead.c: remove redundant null check on calling free()

    this removes simply unneeded code from XauReadAuth
Signed-off-by: Walter Harms <wharms@bfs.de>
Reviewed-by: Daniel Martin <consume.noise@gmail.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

libXau is integrated into libNX_X11, but the differences to libXau
original code where not explicitly marked. This path adds some ifdefs
and also restores the original code.

Attributes to ArcticaProject/nx-libs#850

 This has already been started while replacing copyright info in file
 headers and has now been completed with this commit.

 In the process of building nxagent against more and more system-wide installed
 X.org libraries, we come to the limit of including structs from this (bundled
 nx-X11) and that (system-wide X.Org) library.

 This commit introduces a clear namespace separation of headers provided by
 nx-X11 and headers provided by X.Org. This approach is only temporary as we
 want to drop all nx-X11 bundled libraries from nx-libs.

 However, for a while we need to make this separation clear and also ship
 some reduced fake X.Org headers that avoid pulling in libX* and libNX_X*
 symbols at the same time.

 This patch has been tested on Debian jessie and unstable and requires no
 overall testing on various distros and distro versions, as we finally will
 drop all libNX_X* libraries and build against X.org's client libs.

 For now, this hack eases our development / cleanup process.

Summary: Imported nx-X11-3.1.0-1.tar.gz
Keywords:

Imported nx-X11-3.1.0-1.tar.gz
into Git repository