Fix compilation on libxcb 1.5

libxkbcommon-x11 uses xcb_discard_reply() function which was
introduced in libxcb 1.6, this brakes the compilation in
src/3rdparty/xkbcommon/src/x11/util.c when linking with libxcb 1.5 :

linking ../../../../plugins/platforms/libqxcb.so
.obj/util.o: In function `adopt_atoms':
util.c:(.text+0x347): undefined reference to `xcb_discard_reply'
collect2: error: ld returned 1 exit status

We can use an alternative approach to discard uncollected replies
and in addition add a fix for out-of-bounds error [1]

[1] https://github.com/xkbcommon/libxkbcommon/commit/e3f751be660e28e48d1477660e99e5456c864296

Task-number: QTBUG-38952
Change-Id: Ide90f9a2e75fc79d2bab0b81adb282c8cc81c345
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>
Direct2D QPA: Fix version check

It turns out that the version we were testing against was more recent than
basic Windows 7 SP1 + Platform Update. The direct2d version that
combination produces without any other updates is 6.2.9200.16492, and it
is sufficient for us.

Change-Id: Ib9840647371e2bb5c71bf74486348444ed4b4c19
Reviewed-by: Risto Avila <risto.avila@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Direct2D QPA: Stroke using direct2d primitives

Use native direct2d stroking instead of falling back to
QPaintEngineEx::stroke which in turn calls the pure virtual
QPaintEngineEx::fill which is reimplemented in QWindowsDirect2DPaintEngine.

In some cases like arc stroking this is significantly faster (up to 3x in
my measurements) and results in better visual quality.

Change-Id: I1c86ff772ba591432ff6550c7c59704ace4f0e0f
Reviewed-by: Risto Avila <risto.avila@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Direct2D QPA: Use correct buffer size constant

Change-Id: I2d8ec5faed959d6d642242b3e26ee0f185ee3d53
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Fix crash in QNetworkAccessManager.

Recreating QCoreApplication could cause a crash in QNetworkAccessManager
constructor. That was caused by an invalid shutdown detection introduced
in f273d6fbc02055ff3999adc0df76360ca0670435.

Task-number: QTBUG-36897
Change-Id: Ib5bba773a2a4fcde690a3a93680aef551aae3a5b
Reviewed-by: Peter Hartmann <phartmann@blackberry.com>
Fix potential null pointer access

Change-Id: I7516ce88b38609ab9851419566141ba93a59aed3
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
CMake: Don't FATAL_ERROR if GL libraries can not be found.

For Windows builds, the necessary libraries are not found
in the sdk if the wrong environment is used, which is quite
common.

Task-number: QTBUG-34940
Change-Id: I7d844649790cbfacab3154a717d318fd570c4149
Reviewed-by: Brad King <brad.king@kitware.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>
Windows QPA: Remove dependency on swprintf_s() pulled in via _com_error::ErrorMessage().

Task-number: QTBUG-35617
Change-Id: I0ad926ac564612ebd0eb38f16b3e69cbcd48e62f
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Avoid accessing the internals of the SSL_CIPHER struct.

Avoid accessing the internals of the SSL_CIPHER struct since this has
changed size etc. over time leading to binary incompatibilities.

Task-number: QTBUG-32423
Task-number: QTBUG-23363
Change-Id: I8cb399484e3a62be7d511f4b8b22c876825c87d4
Reviewed-by: Peter Hartmann <phartmann@blackberry.com>
Reviewed-by: Daniel Molkentin <daniel@molkentin.de>