Merge remote-tracking branch 'origin/5.4' into dev

Conflicts:
	src/core/browser_context_qt.cpp
	src/webengine/api/qquickwebengineview_p.h

Change-Id: I73bdec03b627b282851d7dda12006d4ab631072c

1 files changed, 13 insertions, 4 deletions

diff --git a/src/webengine/api/qtwebengineglobal.cpp b/src/webengine/api/qtwebengineglobal.cpp
index ea119bba6..b179da2fe 100644
--- a/src/webengine/api/qtwebengineglobal.cpp
+++ b/src/webengine/api/qtwebengineglobal.cpp
@@ -43,6 +43,7 @@
 QT_BEGIN_NAMESPACE
 
 Q_GUI_EXPORT void qt_gl_set_global_share_context(QOpenGLContext *context);
+Q_GUI_EXPORT QOpenGLContext *qt_gl_global_share_context();
 
 namespace QtWebEngine {
 
@@ -54,8 +55,20 @@ static void deleteShareContext()
     shareContext = 0;
 }
 
+// ### Qt 6: unify this logic and Qt::AA_ShareOpenGLContexts.
+// QtWebEngine::initialize was introduced first and meant to be called
+// after the QGuiApplication creation, when AA_ShareOpenGLContexts fills
+// the same need but the flag has to be set earlier.
 void initialize()
 {
+#ifdef Q_OS_WIN32
+    qputenv("QT_D3DCREATE_MULTITHREADED", "1");
+#endif
+
+    // No need to override the shared context if QApplication already set one (e.g with Qt::AA_ShareOpenGLContexts).
+    if (qt_gl_global_share_context())
+        return;
+
     QCoreApplication *app = QCoreApplication::instance();
     if (!app) {
         qFatal("QWebEngine(Widgets)::initialize() must be called after the construction of the application object.");
@@ -69,10 +82,6 @@ void initialize()
     if (shareContext)
         return;
 
-#ifdef Q_OS_WIN32
-    qputenv("QT_D3DCREATE_MULTITHREADED", "1");
-#endif
-
     shareContext = new QOpenGLContext;
     shareContext->create();
     qAddPostRoutine(deleteShareContext);