From 91120599aee881bd1021087bae91fd1d5de46a4c Mon Sep 17 00:00:00 2001
From: Friedemann Kleint <Friedemann.Kleint@qt.io>
Date: Mon, 6 Feb 2017 12:55:55 +0100
Subject: [PATCH] QRasterPlatformPixmap::createPixmapForImage(): preserve DPR

Remove the line setting the DPR from the source; the image
is moved.

Task-number: QTBUG-58653
Task-number: QTBUG-58645
Change-Id: I2de94681459dba1d69dee06da44617fb9fa35bcc
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
---
 src/gui/image/qpixmap_raster.cpp             |  2 --
 tests/auto/gui/image/qpixmap/tst_qpixmap.cpp | 14 ++++++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/gui/image/qpixmap_raster.cpp b/src/gui/image/qpixmap_raster.cpp
index 54a5b94840..7eb61adb2d 100644
--- a/src/gui/image/qpixmap_raster.cpp
+++ b/src/gui/image/qpixmap_raster.cpp
@@ -349,8 +349,6 @@ void QRasterPlatformPixmap::createPixmapForImage(QImage sourceImage, Qt::ImageCo
     }
     is_null = (w <= 0 || h <= 0);
 
-    if (image.d)
-        image.d->devicePixelRatio = sourceImage.devicePixelRatio();
     //ensure the pixmap and the image resulting from toImage() have the same cacheKey();
     setSerialNumber(image.cacheKey() >> 32);
     if (image.d)
diff --git a/tests/auto/gui/image/qpixmap/tst_qpixmap.cpp b/tests/auto/gui/image/qpixmap/tst_qpixmap.cpp
index 72609d4095..e3bda6c2df 100644
--- a/tests/auto/gui/image/qpixmap/tst_qpixmap.cpp
+++ b/tests/auto/gui/image/qpixmap/tst_qpixmap.cpp
@@ -119,6 +119,7 @@ private slots:
     void refUnref();
 
     void copy();
+    void deepCopyPreservesDpr();
     void depthOfNullObjects();
 
     void transformed();
@@ -1133,6 +1134,19 @@ void tst_QPixmap::copy()
     QCOMPARE(trans, transCopy);
 }
 
+// QTBUG-58653: Force a deep copy of a pixmap by
+// having a QPainter and check whether DevicePixelRatio is preserved
+void tst_QPixmap::deepCopyPreservesDpr()
+{
+    const qreal dpr = 2;
+    QPixmap src(32, 32);
+    src.setDevicePixelRatio(dpr);
+    src.fill(Qt::red);
+    QPainter painter(&src);
+    const QPixmap dest = src.copy();
+    QCOMPARE(dest.devicePixelRatio(), dpr);
+}
+
 void tst_QPixmap::depthOfNullObjects()
 {
     QBitmap b1;