Won't respect --no-playlist at youtube playlist url

[fakio]

• I'm reporting a broken site support
• I've verified that I'm running youtube-dl version 2019.04.30
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar issues including closed ones

Verbose log

[youtube:playlist] PLKc2XOQp0dMwj9zAXD5LlWpriIXIrGaNb: Downloading webpage
[download] Downloading playlist: Calculus: Single Variable by Professor Robert Ghrist
[youtube:playlist] playlist Calculus: Single Variable by Professor Robert Ghrist: Downloading 81 videos
[download] Downloading video 1 of 81
[youtube] nqDVJFlahpU: Downloading webpage
[youtube] nqDVJFlahpU: Downloading video info webpage
[youtube] Downloading just video nqDVJFlahpU because of --no-playlist
[download] Destination: Calculus Chapter 1 Lecture 0-nqDVJFlahpU.mp4
[download] 100% of 49.33MiB in 00:09
[download] Downloading video 2 of 81
[youtube] LYCwHcHRhCg: Downloading webpage
[youtube] LYCwHcHRhCg: Downloading video info webpage
[youtube] Downloading just video LYCwHcHRhCg because of --no-playlist
WARNING: unable to extract channel id; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
[download] Destination: Calculus Chapter 1 Lecture 1 Functions-LYCwHcHRhCg.mp4
[download] 100% of 39.37MiB in 00:07
[download] Downloading video 3 of 81
[youtube] M7Q8pkQ1msg: Downloading webpage
[youtube] M7Q8pkQ1msg: Downloading video info webpage
[youtube] Downloading just video M7Q8pkQ1msg because of --no-playlist
WARNING: unable to extract channel id; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
[download] Destination: Calculus Chapter 1 Lecture 2 Exponentials-M7Q8pkQ1msg.mp4
[download]   8.5% of 36.45MiB at  1.56MiB/s ETA 00:21

Description

Playlist: https://www.youtube.com/playlist?list=PLKc2XOQp0dMwj9zAXD5LlWpriIXIrGaNb

I suppose that using --no-playlist at playlist url shouldn't download the entire playlist, maybe just the first video, but it is not exactly clear to me the expected behavior. Youtube-dl outputs both:

[youtube:playlist] playlist Calculus: Single Variable by Professor Robert Ghrist: Downloading 81 videos

and

[youtube] Downloading just video nqDVJFlahpU because of --no-playlist

[dstftw]

This is expected behavior. Read command description.

[fakio]

The documentation doesn't mention when the url is a playlist

--no-playlist                    Download only the video, if the URL refers
                                 to a video and a playlist.

I was looking for a parameter to limit the number of videos youtube-dl could download to at most 1, even for a playlist. I'll try using --playlist-end.