Fix two errors in RGB30 conversions

The one converters from RGB30 was misplaced in the method table, and
the unpremultiplication from A2RGB30 to RGB30 had an underflow mistake
when alpha was 2.

Change-Id: I92c11ede28611a3dbdce72aca1898845c120c209
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/auto/gui/image/qimage/tst_qimage.cpp b/tests/auto/gui/image/qimage/tst_qimage.cpp
index 51e4c6233e..266230de38 100644
--- a/tests/auto/gui/image/qimage/tst_qimage.cpp
+++ b/tests/auto/gui/image/qimage/tst_qimage.cpp
@@ -183,6 +183,7 @@ private slots:
     void cleanupFunctions();
 
     void devicePixelRatio();
+    void rgb30Unpremul();
 
     void metadataPassthrough();
 
@@ -2829,6 +2830,20 @@ void tst_QImage::devicePixelRatio()
     QCOMPARE(b.devicePixelRatio(), qreal(1.0));
 }
 
+void tst_QImage::rgb30Unpremul()
+{
+    QImage a(3, 1, QImage::Format_A2RGB30_Premultiplied);
+    ((uint*)a.bits())[0] = (3U << 30) | (128 << 20) | (256 << 10) | 512;
+    ((uint*)a.bits())[1] = (2U << 30) | (131 << 20) | (259 << 10) | 515;
+    ((uint*)a.bits())[2] = (1U << 30) | ( 67 << 20) | (131 << 10) | 259;
+
+    QImage b = a.convertToFormat(QImage::Format_RGB30);
+    const uint* bbits = (const uint*)b.bits();
+    QCOMPARE(bbits[0], (3U << 30) | (128 << 20) | (256 << 10) | 512);
+    QCOMPARE(bbits[1], (3U << 30) | (196 << 20) | (388 << 10) | 772);
+    QCOMPARE(bbits[2], (3U << 30) | (201 << 20) | (393 << 10) | 777);
+}
+
 void tst_QImage::metadataPassthrough()
 {
     QImage a(64, 64, QImage::Format_ARGB32);