Fix qdrawhelper function toRGB64

The function was incorrectly handling green and blue color channels
causing them to be dropped. This affects drawing non 32-bit images onto
10-bit per color channels formats such as RGB30.

Change-Id: I9211e253b1a9da0dada5c418d592a8f531265989
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/auto/gui/painting/qpainter/tst_qpainter.cpp b/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
index c729b2f94c..cf4979e291 100644
--- a/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
+++ b/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
@@ -301,6 +301,7 @@ private slots:
     void QTBUG56252();
 
     void blendNullRGB32();
+    void toRGB64();
 
 private:
     void fillData();
@@ -5159,6 +5160,21 @@ void tst_QPainter::blendNullRGB32()
         QVERIFY(image.pixel(i,0) != 0xffffffff);
 }
 
+void tst_QPainter::toRGB64()
+{
+    QImage dst(10, 1, QImage::Format_BGR30);
+    QImage src(10, 1, QImage::Format_RGB16);
+    src.fill(Qt::white);
+
+    QPainter paint(&dst);
+    paint.drawImage(0, 0, src);
+    paint.end();
+
+    for (int i=0; i < dst.width(); ++i) {
+        QVERIFY(dst.pixelColor(i,0) == QColor(Qt::white));
+    }
+}
+
 QTEST_MAIN(tst_QPainter)
 
 #include "tst_qpainter.moc"