Special characters in playlist title causes unexpected behaviour

[CaptainBlagbird]

How to reproduce:

1. Set OUTPUT_TEMPLATE to %(playlist_title)s_%(title)s.%(ext)s or similar
2. Download the following youtube playlist: https://www.youtube.com/playlist?list=PLHhbws8qZazp4u0l_SrdDHOKhjW4g9r4a (it contains only one short video)

Expected behaviour

The playlist title is "A/B" and the video title is "C/D", so I expect the name of the output file to be "A/B_C/D" in the download directory.

Actual behaviour

A file with name "B_C/D" is created in a subdirectory named "A". So apparently the slash is interpreted as directory symbol, however only in the playlist title and not the video title.

Other info

• I created the following python script and ran it in the same docker container:

  from yt_dlp import YoutubeDL
  
  opts = {"outtmpl":{"default":"%(playlist_title)s_%(title)s.%(ext)s"}}
  
  with YoutubeDL(opts) as ydl:
      ydl.download("https://www.youtube.com/playlist?list=PLHhbws8qZazp4u0l_SrdDHOKhjW4g9r4a")

  Here, the problem does not happen and the result is according to the expected behavour.

• When using option restrictfilenames, the directory A is still created and the file is called "B_C_D". (With the script: No directory and file name "A_B_C_D").

[CaptainBlagbird]

It has probably something to do with this line.

[PikuZheng]

no issue with mine

[CaptainBlagbird]

@PikuZheng In your screenshot the "M/V" and "C/D" are part of %(title)s, this works. However it does not work for %(playlist_title)s, which I can not see in your screenshot.

[PikuZheng]

I see.
"/" in %(title)s and %(playlist_title)s is "\u29F8", which is correct in yt-dlp