qmake5_base.bbclass: set qt.conf by environment variable again

Qt update to 5.8 caused fallout in meta-qt5-extra. It turned out that
qmake pulled in many pointers to native sysroot. Native sysroot is qmake's
default in case no configuration file qt.conf is set.
The problem with the new way of setting qt.conf by cmd parameter is that is has
to be set explicitly. For instance all the packages coming from [1] use
autotools for configuration. These ask qmake for paths during configuration
and build further Makefiles during compile. To patch these for additional cmd
parameter is nasty business.
Setting qt.conf when building all qtbase's causes errors during configuration.
To fix this we set the filename to a non existent file so that Qt's default is
used. This dirty hack was necessary because there was no way found to export
an empty variable OE_QMAKE_QTCONF_PATH.

This patch was tested by building huge parts of meta-qt5-extra. The meta-layers
did not yet contain oe-core's recipe-specific-sysroot changes so master build
might fail for missing dependencies.

[1] http://www.rncbc.org/drupal/

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/recipes-qt/qt5/qtbase/0002-qlibraryinfo-allow-to-set-qt.conf-from-the-outside-u.patch b/recipes-qt/qt5/qtbase/0002-qlibraryinfo-allow-to-set-qt.conf-from-the-outside-u.patch
new file mode 100644
index 00000000..4b72ebf1
--- /dev/null
+++ b/recipes-qt/qt5/qtbase/0002-qlibraryinfo-allow-to-set-qt.conf-from-the-outside-u.patch
@@ -0,0 +1,38 @@
+From e5f8607cfa1d2bcc798686cdf7c87ea0c6577d30 Mon Sep 17 00:00:00 2001
+From: Holger Freyther <zecke@selfish.org>
+Date: Wed, 26 Sep 2012 17:22:30 +0200
+Subject: [PATCH] qlibraryinfo: allow to set qt.conf from the outside using the
+ environment
+
+Allow to set a qt.conf from the outside using the environment. This allows
+to inject new prefixes and other paths into qmake. This is needed when using
+the same qmake binary to build qt/x11 and qt/embedded
+
+Upstream-Status: Inappropriate [embedded specific]
+  again very OE specific to read everything from environment (reusing the same
+  qmake from sstate and replacing all configured paths in it with qt.conf from
+  environment).
+
+Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
+---
+ src/corelib/global/qlibraryinfo.cpp | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
+index 27fe10a..29ffcda 100644
+--- a/src/corelib/global/qlibraryinfo.cpp
++++ b/src/corelib/global/qlibraryinfo.cpp
+@@ -164,7 +164,10 @@ void QLibrarySettings::load()
+ QSettings *QLibraryInfoPrivate::findConfiguration()
+ {
+ #ifdef QT_BUILD_QMAKE
+-    QString qtconfig = qmake_libraryInfoFile();
++    QByteArray config = getenv("OE_QMAKE_QTCONF_PATH");
++    QString qtconfig = QFile::decodeName(config);
++    if(!QFile::exists(qtconfig))
++        qtconfig = qmake_libraryInfoFile();
+     if (QFile::exists(qtconfig))
+         return new QSettings(qtconfig, QSettings::IniFormat);
+ #else
+-- 
+2.9.3