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-rw-r--r--src/gui/image/qimage_p.h33
1 files changed, 33 insertions, 0 deletions
diff --git a/src/gui/image/qimage_p.h b/src/gui/image/qimage_p.h
index 2fe29a88d3..e3a6c53833 100644
--- a/src/gui/image/qimage_p.h
+++ b/src/gui/image/qimage_p.h
@@ -52,6 +52,7 @@
//
#include <QtGui/private/qtguiglobal_p.h>
+#include <QtCore/private/qnumeric_p.h>
#include <QMap>
#include <QVector>
@@ -104,8 +105,40 @@ struct Q_GUI_EXPORT QImageData { // internal image data
bool doImageIO(const QImage *image, QImageWriter* io, int quality) const;
QPaintEngine *paintEngine;
+
+ struct ImageSizeParameters {
+ qsizetype bytesPerLine;
+ qsizetype totalSize;
+ };
+ static ImageSizeParameters calculateImageParameters(qsizetype width, qsizetype height, qsizetype depth);
};
+inline QImageData::ImageSizeParameters
+QImageData::calculateImageParameters(qsizetype width, qsizetype height, qsizetype depth)
+{
+ ImageSizeParameters invalid = { -1, -1 };
+ if (height <= 0)
+ return invalid;
+
+ // calculate the size, taking care of overflows
+ qsizetype bytes_per_line;
+ if (mul_overflow(width, depth, &bytes_per_line))
+ return invalid;
+ if (add_overflow(bytes_per_line, qsizetype(31), &bytes_per_line))
+ return invalid;
+ // bytes per scanline (must be multiple of 4)
+ bytes_per_line = (bytes_per_line >> 5) << 2; // can't overflow
+
+ qsizetype total_size;
+ if (mul_overflow(height, bytes_per_line, &total_size))
+ return invalid;
+ qsizetype dummy;
+ if (mul_overflow(height, qsizetype(sizeof(uchar *)), &dummy))
+ return invalid; // why is this here?
+
+ return { bytes_per_line, total_size };
+}
+
typedef void (*Image_Converter)(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags);
typedef bool (*InPlace_Image_Converter)(QImageData *data, Qt::ImageConversionFlags);