There is a heap corruption bug that can occur when QT
processes a malformed TIFF image. It happens because the size of
the QImageData backing the image is calculated is calculated using
the format of the image, meanwhile TIFFReadScanline calculates the
length to be read based on TIFFScanlineSize, which determines the
size base on three tags in the TIFF file, width, samples per pixel
and bits per sample.
