[vile] FTP URL acting strange

[Wayne Cuddy]

I maintain the slackbuild for vile, currently using rev 9.8s.

It's worked in the past for many years but something has recently
broken the FTP URL source path via curl.

Here is a build attempt that fails at the download phase:

address@hidden:/tmp# slapt-src -i vile
The following packages will be installed:
 vile 
Do you want to continue? [y/N] y
Fetching README...Done
Fetching patches/sh-filt.patch...Done
Fetching slack-desc...Done
Fetching vile.SlackBuild...Done
Fetching vile.info...Done
Fetching
ftp://ftp.invisible-island.net/vile/current/vile-9.8s.tgz...Failed

Most of these tools use libcurl to acquire the source, here is curl run
with debug enabled:
address@hidden:/tmp# curl -v -O 
'ftp://ftp.invisible-island.net/vile/current/vile-9.8t.tgz'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0* 
  Trying 216.194.196.78...
* TCP_NODELAY set
* Connected to ftp.invisible-island.net (216.194.196.78) port 21 (#0)
< 220 ProFTPD Server (ftp.invisible-island.net) [216.194.196.78]
> USER anonymous
< 331 Anonymous login ok, send your complete email address as your password
> PASS address@hidden
< 230 Anonymous access granted, restrictions apply
> PWD
< 257 "/" is the current directory
* Entry path is '/'
> CWD vile
* ftp_perform ends with SECONDARY: 0
< 550 vile: No such file or directory
* Server denied you to change to the given directory
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
* Connection #0 to host ftp.invisible-island.net left intact
curl: (9) Server denied you to change to the given directory

Here is the same URL working with wget:
address@hidden:/tmp# wget -d 
'ftp://ftp.invisible-island.net/vile/current/vile-9.8t.tgz'
DEBUG output created by Wget 1.20.3 on linux-gnu.
                
Reading HSTS entries from /root/.wget-hsts
Converted file name 'vile-9.8t.tgz' (UTF-8) -> 'vile-9.8t.tgz' (ISO-8859-1)
--2019-04-07 12:28:35--  
ftp://ftp.invisible-island.net/vile/current/vile-9.8t.tgz
           => 'vile-9.8t.tgz'
Resolving ftp.invisible-island.net... 216.194.196.78
Caching ftp.invisible-island.net => 216.194.196.78
Connecting to ftp.invisible-island.net|216.194.196.78|:21... connected.
Created socket 3.
Releasing 0x000000000096f610 (new refcount 1).
220 ProFTPD Server (ftp.invisible-island.net) [216.194.196.78]
Logging in as anonymous ...
--> USER anonymous
                
331 Anonymous login ok, send your complete email address as your password
                
--> PASS -wget@ 
                
230 Anonymous access granted, restrictions apply
Logged in!      
==> SYST ...    
--> SYST        
                
215 UNIX Type: L8
done.           
UNIX TYPE L8: I know it and I will use "LIST -a" as standard list command
==> PWD ...     
--> PWD         
                
257 "/" is the current directory
done.
==> TYPE I ...
--> TYPE I

200 Type set to I
done.  changing working directory
Prepended initial PWD to relative path:
   pwd: '/'     
   old: 'vile/current'
  new: '/vile/current'
==> CWD (1) /vile/current ...
--> CWD /vile/current
                
250 CWD command successful
done.           
==> SIZE vile-9.8t.tgz ...
--> SIZE vile-9.8t.tgz
                
213 2352119     
2352119         
conaddr is: 216.194.196.78
==> PASV ...    
--> PASV        
                
227 Entering Passive Mode (216,194,196,78,225,149).
trying to connect to 216.194.196.78 port 57749
Created socket 4.
done.    ==> RETR vile-9.8t.tgz ...
--> RETR vile-9.8t.tgz
                
150 Opening BINARY mode data connection for vile-9.8t.tgz (2352119 bytes)
done.           
Length: 2352119 (2.2M) (unauthoritative)
                
vile-9.8t.tgz                  
100%[=================================================>]   2.24M   450KB/s    
in 5.1s
                
Closed fd 4     
226 Transfer complete
Closed fd 3     
2019-04-07 12:28:41 (452 KB/s) - 'vile-9.8t.tgz' saved [2352119]


The problem appears to permissions in the intial /vile directory?

Connected to ftp.invisible-island.net (216.194.196.78).
220 ProFTPD Server (ftp.invisible-island.net) [216.194.196.78]
Name (ftp.invisible-island.net:wcuddy): anonymous
331 Anonymous login ok, send your complete email address as your password
Password:
230 Anonymous access granted, restrictions apply
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd /vile
550 /vile: No such file or directory
ftp> cd /vile/current
250 CWD command successful

Looks like curl changes directories one at time but wget performs
the complete CD at once.

I can get curl to work inserting /pub into the URL:
ftp://ftp.invisible-island.net/pub/vile/current/vile-9.8t.tgz

Should I update the slackbuild with /pub inserted or is this temporary
situation.

Wayne