Fix QGLWidgets created with an alpha channel on X11/EGL

If the QGLWidget's QGLFormat says it should have an alpha
channel, try to find an ARGB Visual.

Reviewed-By: Trond
Task-number: QT-2602

1 files changed, 1 insertions, 1 deletions

diff --git a/src/opengl/qgl_x11egl.cpp b/src/opengl/qgl_x11egl.cpp
index b10e7e9..19026b3 100644
--- a/src/opengl/qgl_x11egl.cpp
+++ b/src/opengl/qgl_x11egl.cpp
@@ -336,7 +336,7 @@ void QGLWidget::setContext(QGLContext *context, const QGLContext* shareContext,
     // If the application has set WA_TranslucentBackground and not explicitly set
     // the alpha buffer size to zero, modify the format so it have an alpha channel
     QGLFormat& fmt = d->glcx->d_func()->glFormat;
-    const bool tryArgbVisual = testAttribute(Qt::WA_TranslucentBackground);
+    const bool tryArgbVisual = testAttribute(Qt::WA_TranslucentBackground) || fmt.alpha();
     if (tryArgbVisual && fmt.alphaBufferSize() == -1)
         fmt.setAlphaBufferSize(1);