Fix alpha handling of QImage::setPixel

It was treated differently depending on format, made it consistently
behave the same for all formats (following the behavior of the primary
formats).

Change-Id: Ie24e19957d076fdf3ebd333074e26ede187489eb
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
(cherry picked from commit c32cd44d34910cfd42e32537578e4a573138a282)

2 files changed, 26 insertions, 7 deletions

diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index 7fe7914c0c..4d3255661e 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -2497,7 +2497,7 @@ void QImage::setPixel(int x, int y, uint index_or_rgb)
         ((uint *)s)[x] = index_or_rgb;
         return;
     case Format_RGB16:
-        ((quint16 *)s)[x] = qConvertRgb32To16(qUnpremultiply(index_or_rgb));
+        ((quint16 *)s)[x] = qConvertRgb32To16(index_or_rgb);
         return;
     case Format_RGBX8888:
         ((uint *)s)[x] = ARGB2RGBA(0xff000000 | index_or_rgb);
@@ -2518,6 +2518,10 @@ void QImage::setPixel(int x, int y, uint index_or_rgb)
     case Format_A2RGB30_Premultiplied:
         ((uint *)s)[x] = qConvertArgb32ToA2rgb30<PixelOrderRGB>(index_or_rgb);
         return;
+    case Format_RGBA64:
+    case Format_RGBA64_Premultiplied:
+        ((QRgba64 *)s)[x] = QRgba64::fromArgb32(index_or_rgb);
+        return;
     case Format_Invalid:
     case NImageFormats:
         Q_ASSERT(false);
@@ -2527,7 +2531,10 @@ void QImage::setPixel(int x, int y, uint index_or_rgb)
     }
 
     const QPixelLayout *layout = &qPixelLayouts[d->format];
-    layout->storeFromARGB32PM(s, &index_or_rgb, x, 1, nullptr, nullptr);
+    if (!hasAlphaChannel())
+        layout->storeFromRGB32(s, &index_or_rgb, x, 1, nullptr, nullptr);
+    else
+        layout->storeFromARGB32PM(s, &index_or_rgb, x, 1, nullptr, nullptr);
 }
 
 /*!
diff --git a/src/gui/painting/qdrawhelper.cpp b/src/gui/painting/qdrawhelper.cpp
index 3b680b3f3f..71168e901f 100644
--- a/src/gui/painting/qdrawhelper.cpp
+++ b/src/gui/painting/qdrawhelper.cpp
@@ -1419,7 +1419,7 @@ static void QT_FASTCALL storeRGB64FromRGB32(uchar *dest, const uint *src, int in
 {
     QRgba64 *d = reinterpret_cast<QRgba64 *>(dest) + index;
     for (int i = 0; i < count; ++i)
-        d[i] = QRgba64::fromArgb32(src[i]);
+        d[i] = QRgba64::fromArgb32(src[i] | 0xff000000);
 }
 
 static const uint *QT_FASTCALL fetchRGBA64ToARGB32PM(uint *buffer, const uchar *src, int index, int count,
@@ -1431,12 +1431,24 @@ static const uint *QT_FASTCALL fetchRGBA64ToARGB32PM(uint *buffer, const uchar *
     return buffer;
 }
 
+template<bool Mask>
 static void QT_FASTCALL storeRGBA64FromARGB32PM(uchar *dest, const uint *src, int index, int count,
                                                 const QVector<QRgb> *, QDitherInfo *)
 {
     QRgba64 *d = reinterpret_cast<QRgba64 *>(dest) + index;
-    for (int i = 0; i < count; ++i)
+    for (int i = 0; i < count; ++i) {
         d[i] = QRgba64::fromArgb32(src[i]).unpremultiplied();
+        if (Mask)
+            d[i].setAlpha(65535);
+    }
+}
+
+static void QT_FASTCALL storeRGBA64FromARGB32(uchar *dest, const uint *src, int index, int count,
+                                              const QVector<QRgb> *, QDitherInfo *)
+{
+    QRgba64 *d = reinterpret_cast<QRgba64 *>(dest) + index;
+    for (int i = 0; i < count; ++i)
+        d[i] = QRgba64::fromArgb32(src[i]);
 }
 
 // Note:
@@ -1523,15 +1535,15 @@ QPixelLayout qPixelLayouts[QImage::NImageFormats] = {
     { false, false, QPixelLayout::BPP64, nullptr,
       convertPassThrough, nullptr,
       fetchRGB64ToRGB32, fetchPassThrough64,
-      storeRGB64FromRGB32, storeRGB64FromRGB32 }, // Format_RGBX64
+      storeRGBA64FromARGB32PM<true>, storeRGB64FromRGB32 }, // Format_RGBX64
     { true, false, QPixelLayout::BPP64, nullptr,
       convertARGB32ToARGB32PM, nullptr,
       fetchRGBA64ToARGB32PM, fetchRGBA64ToRGBA64PM,
-      storeRGBA64FromARGB32PM, storeRGB64FromRGB32 }, // Format_RGBA64
+      storeRGBA64FromARGB32PM<false>, storeRGB64FromRGB32 }, // Format_RGBA64
     { true, true, QPixelLayout::BPP64, nullptr,
       convertPassThrough, nullptr,
       fetchRGB64ToRGB32, fetchPassThrough64,
-      storeRGB64FromRGB32, storeRGB64FromRGB32 }, // Format_RGBA64_Premultiplied
+      storeRGBA64FromARGB32, storeRGB64FromRGB32 }, // Format_RGBA64_Premultiplied
     { false, false, QPixelLayout::BPP16, nullptr,
       convertGrayscale16ToRGB32, convertGrayscale16ToRGBA64,
       fetchGrayscale16ToRGB32, fetchGrayscale16ToRGBA64,