sending MLSD command even if the server doesn't support it

[Rogerz Zhang]

When connecting to an internal FTP server with FileZilla Client, it was disconnected after sending a MLSD command. I don't know the server type but according to the result of FEAT, it doesn't support MLSD. FileZilla didn't provide me an option of not using MLSD.

Command: SYST
Response: 215 UNIX Type: L8
Command: FEAT
Response: 211-Features:
Response: MDTM
Response: MFMT
Response: TVFS
Response: MFF modify;UNIX.group;UNIX.mode;
Response: MLST modify*;perm*;size*;type*;unique*;UNIX.group*;UNIX.mode*;UNIX.owner*;
Response: REST STREAM
Response: SIZE
Response: 211 End
Status: Connected
Status: Retrieving directory listing...
Command: PWD
Response: 257 "/" is the current directory
Command: TYPE I
Response: 200 Type set to I
Command: PASV
Response: 227 Entering Passive Mode (10,198,155,23,201,148).
Command: MLSD
Error: Disconnected from server: ECONNABORTED - Connection aborted
Error: Failed to retrieve directory listing

[Alexander Schuch]

"Support for the LIST command will be removed. In its place MLSD will be used as defined in RFC 3659. The problem with LIST is that its output isn't specified. As such it is impossible to reliably obtain directory listings using LIST. MLSD on the other hand uses a well-defined listing format. MLSD has been introduced more than 8 years ago, by now all server administrators had have more than enough time to upgrade their servers to be MLSD capable." -- ​https://forum.filezilla-project.org/viewtopic.php?t=36597

[Alexander Schuch]

Looks like a joke, doh.

[Alexander Schuch]

Still, the server advertises MLST and MLSD.

As per RFC 3659, support for both MLST and MLSD is indicated via the MLST line in the FEAT output, see section 7.8: ​https://tools.ietf.org/html/rfc3659#page-49.