Make isSharing() reset to false when context no longer sharing

The documentation for QGLContext::isSharing() indicates that
the function returns true only when the context is sharing.
However, previously the sharing flag would stay on if the
context was created as sharing but is no longer sharing.

Task-number: QTBUG-5578
Reviewed-by: Sarah Smith

2 files changed, 2 insertions, 1 deletions

diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 8063fc8..f8a2ea4 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -3030,7 +3030,7 @@ void QGLContext::setValid(bool valid)
 bool QGLContext::isSharing() const
 {
     Q_D(const QGLContext);
-    return d->sharing;
+    return d->group->isSharing();
 }
 
 QGLFormat QGLContext::format() const
diff --git a/src/opengl/qgl_p.h b/src/opengl/qgl_p.h
index 9a17c67..45b2942 100644
--- a/src/opengl/qgl_p.h
+++ b/src/opengl/qgl_p.h
@@ -233,6 +233,7 @@ public:
 
     QGLExtensionFuncs &extensionFuncs() {return m_extensionFuncs;}
     const QGLContext *context() const {return m_context;}
+    bool isSharing() const { return m_shares.size() >= 2; }
 
     void addGuard(QGLSharedResourceGuard *guard);
     void removeGuard(QGLSharedResourceGuard *guard);