Fix another crash when converting format of buffer-created QImage

This continues 68762151dbf45fbb44e140ac2ad13dbe8d357352

When doing format conversion, the optimized inplace codepath did not
check if the image data was external, i.e. if the QImage had been
created by the constructor taking an existing external buffer.

The previous commit fixed the readonly case. But in the case of the
QImage constructor taking non-const uchar*, data will be read-write,
but still external. This would of course crash if the converter tries
to realloc it.

Task-number: QTBUG-44610
Change-Id: I94d275d464e8af221682b538fc3e4897a59c061e
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@theqtcompany.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/tests/auto/gui/image/qimage/tst_qimage.cpp b/tests/auto/gui/image/qimage/tst_qimage.cpp
index e8da3263ae..309d3a80c5 100644
--- a/tests/auto/gui/image/qimage/tst_qimage.cpp
+++ b/tests/auto/gui/image/qimage/tst_qimage.cpp
@@ -2456,6 +2456,7 @@ void tst_QImage::inplaceConversion_data()
     QTest::addColumn<QImage::Format>("format");
     QTest::addColumn<QImage::Format>("dest_format");
 
+    QTest::newRow("Format_RGB32 -> RGB16") << QImage::Format_RGB32 << QImage::Format_RGB16;
     QTest::newRow("Format_ARGB32 -> Format_RGBA8888") << QImage::Format_ARGB32 << QImage::Format_RGBA8888;
     QTest::newRow("Format_RGB888 -> Format_ARGB6666_Premultiplied") << QImage::Format_RGB888 << QImage::Format_ARGB6666_Premultiplied;
     QTest::newRow("Format_RGB16 -> Format_RGB555") << QImage::Format_RGB16 << QImage::Format_RGB555;
@@ -2494,16 +2495,21 @@ void tst_QImage::inplaceConversion()
         QCOMPARE(imageConverted.constScanLine(0), originalPtr);
 
     {
-        // Test attempted inplace conversion of images created on existing, readonly buffer
+        // Test attempted inplace conversion of images created on existing buffer
         static const quint32 readOnlyData[] = { 0x00010203U, 0x04050607U, 0x08091011U, 0x12131415U };
+        quint32 readWriteData[] = { 0x00010203U, 0x04050607U, 0x08091011U, 0x12131415U };
 
         QImage roImage((const uchar *)readOnlyData, 2, 2, format);
-        QImage inplaceConverted = std::move(roImage).convertToFormat(dest_format);
+        QImage roInplaceConverted = std::move(roImage).convertToFormat(dest_format);
+
+        QImage rwImage((uchar *)readWriteData, 2, 2, format);
+        QImage rwInplaceConverted = std::move(rwImage).convertToFormat(dest_format);
 
         QImage roImage2((const uchar *)readOnlyData, 2, 2, format);
         QImage normalConverted = roImage2.convertToFormat(dest_format);
 
-        QCOMPARE(normalConverted, inplaceConverted);
+        QCOMPARE(normalConverted, roInplaceConverted);
+        QCOMPARE(normalConverted, rwInplaceConverted);
     }
 #endif
 }