Transmission fails to use webseed if any file in the torrent has a colon in its name

[Siguza]

What is the issue?

For any torrent that contains even one file whose name contains a colon, Transmission seems to be completely unable to download from webseeds.
Downloading from peers works fine.

Example torrent from archive.org that triggers the issue: https://archive.org/download/install-assistant-12.0-dp-4-pb-3/install-assistant-12.0-dp-4-pb-3_archive.torrent

(Note that on macOS, Finder will show colons in file names as / instead.)

Which application of Transmission?

macOS app

Which version of Transmission?

3.00 (f4489c9)

[tearfur]

Fixed by #3823.