From f882d2f443a8950a2f784fa91b3ff10a645577f7 Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@qt.io>
Date: Wed, 7 Dec 2016 13:03:44 +0100
Subject: [PATCH] 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>
---
 src/gui/painting/qdrawhelper.cpp                 |  4 ++--
 .../auto/gui/painting/qpainter/tst_qpainter.cpp  | 16 ++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/gui/painting/qdrawhelper.cpp b/src/gui/painting/qdrawhelper.cpp
index 64956d342df..8700a0fce16 100644
--- a/src/gui/painting/qdrawhelper.cpp
+++ b/src/gui/painting/qdrawhelper.cpp
@@ -217,8 +217,8 @@ static const QRgba64 *QT_FASTCALL convertToRGB64(QRgba64 *buffer, const uint *sr
         uint green = (src[i] >> greenShift<Format>()) & greenMask;
         uint blue = (src[i] >> blueShift<Format>()) & blueMask;
 
-        red = ((red << redLeftShift) | (red >> redRightShift)) << 16;
-        green = ((green << greenLeftShift) | (green >> greenRightShift)) << 8;
+        red = ((red << redLeftShift) | (red >> redRightShift));
+        green = ((green << greenLeftShift) | (green >> greenRightShift));
         blue = (blue << blueLeftShift) | (blue >> blueRightShift);
         buffer[i] = QRgba64::fromRgba(red, green, blue, 255);
     }
diff --git a/tests/auto/gui/painting/qpainter/tst_qpainter.cpp b/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
index c729b2f94c8..cf4979e2917 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"