Output incorrect `PictType`

[jessielw]

5.0 and 5.0-RC4 have wrong _PictType while 5.0-RC3 is ok.

This was discovered on this comment HomeOfAviSynthPlusEvolution/L-SMASH-Works#67 (comment)

[arch1t3cht]

Do you have a sample file and steps to reproduce? How do you know which PictType is correct and which is incorrect?

[jessielw]

This isn't quite a sample, it's the entire source file. I don't have much time to split it apart this morning, but if you can't wait until later here is the full source link.

https://drive.google.com/file/d/16gVyoD4LbZn6nQNjYBX89_ODaAVQGbIT/view?usp=drive_link
Password is lsmash.

Edit:
Here is a smaller sample of the file where the problem exists
https://drive.google.com/file/d/1MxTDH3XG3uquMpix4idhRRbIVavk8uxR/view?usp=sharing