Post #996712

@mwk@donotsta.re Had a similar experience when writing JPEG XL header parsing. There's so little invalid states, that the only way I could see that I made a mistake was by trying to read past the end of the file if I got some ridiculously large number on one of like 3 string fields - in every other case you had to slowly go through the entire structure comparing to a known-good parse of the header and seeing where it stops matching up.