QImage crashes on save when bytesPerLine is larger than "width" 32 aligned

After more research here is what I have found:

Documentation for 

QImage::QImage(const uchar *data, int width, int height, QImage::Format format, QImageCleanupFunction cleanupFunction = nullptr, void *cleanupInfo = nullptr)

should be updated not only the bytesPerLine  must be aligned on 32 but must be equal to "width" aligned on 32 and no larger.

Original problem:

Qt lib crashes when saving images created from user buffer with bytesPerLine aligned on 32 and larger than width (for example width: 300, bytesPerLine: 320) with format QImage::Format_Grayscale8

At some point during saving Qt allocates temp image with bytesPerLine that is less than the user-created image then later on this code crases:

memcpy(dest->data, src->data, src->bytes_per_line * src->height);

Test code:

static void conversionBufferFree(void *info)\{ _aligned_free(info);} 

void TestQImage()

{ int width = 300; int height = 200; int stride = 320; unsigned char* buff = (unsigned char*)_aligned_malloc(size_t(stride*height), size_t(32)); Q_ASSERT((reinterpret_cast<uintptr_t>(buff) & 3) == 0); memset(buff, 0, stride*height); QImage image(buff, width, height, stride, QImage::Format_Grayscale8, conversionBufferFree, buff); image.save("D:\\0000A.bmp", "bmp");}

problematic code in QT: the problem is that dest->bytes_per_line is 300 and src->bytes_per_line is 320 ; memcpy overwrites memory ->crash

dest is a temp image allocated by Qt for conversion;

static void convert_Grayscale8_to_Indexed8(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags)

{ Q_ASSERT(src->format == QImage::Format_Grayscale8); Q_ASSERT(dest->format == QImage::Format_Indexed8); memcpy(dest->data, src->data, src->bytes_per_line * src->height); <<< CRASH >>>> dest->colortable = defaultColorTables->gray; }