Re: bin/54467: new tar overwrites symlinks to directories

[Martin Husemann <martin%duskware.de@localhost>]

The following reply was made to PR bin/54467; it has been noted by GNATS.

From: Martin Husemann <martin%duskware.de@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: bin/54467: new tar overwrites symlinks to directories
Date: Sat, 17 Aug 2019 22:25:11 +0200

 On Sat, Aug 17, 2019 at 07:50:02PM +0000, Joerg Sonnenberger wrote:
 >  On Thu, Aug 15, 2019 at 04:25:00PM +0000, martin%NetBSD.org@localhost wrote:
 >  > The new tar(1) is overeager in restoring directories if those already exist
 >  > as a symlink to another directory.
 >  
 >  That's how it should behave. Seems like a bug in pax-as-tar if nothing
 >  else.
 
 It should be overridable by some option, at least.
 
 >  > This kills updates on machines that have /usr as a symlink to someplace else
 >  > with our base.tgz containing
 >  > 
 >  > 	 drwxr-xr-x  0 root   wheel        0 Jul 14 16:36 ./usr
 >  
 >  This sounds like it is asking for trouble to me. Why would you ever want
 >  to make /usr a symlink?!
 
 Why not?
 In this concrete case it is the result of history, limited size boot disk
 and maybe suboptimal admin choices a long time ago. It always has worked
 fine, now it is broken.
 
 It is a setup that may happen to others in the real world and we should be
 very carefull before breaking it, and also should prominently warn about it.
 
 Martin