install program : avoiding unnecessary chown()

[Richard Curnow]

I've run into a small problem when using GNU install.  I'm on Linux 2.2.19,
with the destination directory being mounted via smbfs.  (The remote end is
actually samba on Solaris, being used to export a ClearCase view.)  The
invocation of install is using the -m switch, but *not* the -o or -g switches.

install was exiting with an "operation not permitted" error.

Running strace, I could see the problem was coming from a call to chown() with
uid=gid=-1 (i.e. leave owner and group the same).  I've found that in the Linux
kernel, a chown call with either of these arguments =-1 is taken to mean "copy
that arg from what the file has now", rather than "don't bother changing the
file if both are -1".  That method would probably have been wrong anyway, since
the mtime needs to change at least.

The underlying problem is probably that smbfs doesn't support a chown
operation, as I doubt it's part of the SMB protocol.

So, I decided the easiest fix was in install.  If neither the -o nor -g
switches have been specified, don't bother trying to do chown() on the
destination file at all.  I've attached a patch to do this.

-- 
Richard | SuperH Core Architecture  ///                 .... At home ...
Curnow  | address@hidden    ///     address@hidden
        | http://www.superh.com/    /// http://www.rrbcurnow.freeuk.com/

install.patch
Description: Text document