[1]

gecko-dev/nsFtpConnectionThread.cpp at master · mozilla/gecko-dev ( (2016-06-12 17:33:43 +09:00)) https://github.com/mozilla/gecko-dev/blob/master/netwerk/protocol/ftp/nsFtpConnectionThread.cpp

rv = mChannel->PushStreamConverter("text/ftp-dir",
APPLICATION_HTTP_INDEX_FORMAT);

[2] No longer render resources requested via FTP (mikewest著, 2018-12-13 23:59:41 +09:00) https://github.com/whatwg/fetch/commit/c6b3a750f811cb4f628def0313ac317d9dcec88a

[3] Treat resources requested via FTP as binary data. by mikewest · Pull Request #839 · whatwg/fetch (2019-05-31 18:32:13 +09:00) https://github.com/whatwg/fetch/pull/839