Re: pkg/59072: Can't delete vim backup on NetBSD with msdos filesystem

["Frédéric Fauberteau via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR pkg/59072; it has been noted by GNATS.

From: =?UTF-8?B?RnLDqWTDqXJpYyBGYXViZXJ0ZWF1?= <triaxx@triaxx.online>
To: gnats-bugs%NetBSD.org@localhost
Cc: Michael van Elst <mlelstv%serpens.de@localhost>
Subject: Re: pkg/59072: Can't delete vim backup on NetBSD with msdos
 filesystem
Date: Thu, 13 Feb 2025 10:19:51 +0100

 > It's a problem of all, vim, the FAT filesystem and how NetBSD
 > tries to work around the FAT limitations.
 > 
 > You use msdosfs without long names (see the substitute
 > names containing a tilde).
 > 
 > vim saves the original file boot.cfg by renaming it to boot.cfg~. But
 > that's not a valid MS-DOS filename and instead the substitute boot~1.cfg
 > is generated. But when vim tries to delete boot.cfg~ again, no such
 > substitution can be used, because boot~1.cfg could be a different file.
 > The substitution cannot be reverted.
 > 
 > If you use msdosfs with long names (or better with UTF-8 long names),
 > this doesn't happen as vim can create a file with the long name
 > boot.cfg~, the substitute is hidden. And that file can also be deleted.
 > 
 > I'm not sure if you actually mount the filesystem with the '-s' option
 > to disable long names. I suspect, you don't specify any mode and then
 > msdosfs tries to guess. If all files follow the short 8.3 name pattern,
 > then it assumes to have a pre-Win95 filesystem and will automatically
 > chose the '-s' option, otherwise it will chose '-l'.
 > 
 > Best solution for you is to specify the mount option '-U' (implies -l)
 > for UTF-8 mode to be compatible with Windows.
 > 
 > A fstab entry would look like:
 > 
 > NAME=efi  /efi   msdos   rw,-U,-M755,-m644       1 2
 
 Your suspicion is right, I didn't specify any mode to mount the involved 
 msdos filesystem.
 
 I remount my partition with the suggested options:
      # umount /mnt/boot
      # mount -tmsdos -orw,-U,-M755,-m644 /dev/dk2 /mnt/boot
 
 I create a file with a long name:
      # touch /mnt/boot/toolongfilename
 
 But the file name is still truncated:
      # ls /mnt/boot
      efi      toolon~1