A problem we actually have with Peertube is we used the playlist's display name to check if a playlist exists.
But the name for a playlist could only contains 20 characters, minuscule, no spaces and no special char, where the display name is totally free.
So, it's possible we get playlist with identical names BUT different display name, so prismedia will try to create a playlist with a name that already exists (thus getting an HTTP error 409)
To reproduce, create a playlist with name:
Then, create a new playlist with name:
While the display name is different, the name would be
thisatestplaylistwi for both, which create conflicts...
To fix, we could use name instead of display name to check if playlist exists :-)