Jonathan Nieder wrote: > Adam D. Barratt wrote: >> * the preinst isn't idempotent >> - from a few quick tests, it looks like this could be resolved by changing >> the execution order to "cp, ln, divert" rather than "divert, cp, ln"; I >> may have missed something, however > > Technically one would need > > # nothing except dash prerm seems to care about the .distrib > # file, so this is relatively safe. > cp -dp $dfile $distrib > > # ln -sf is not idempotent, though ln -s to temporary + mv is. > ln -sf $ltarget $tmpfile > mv -f $tmpfile $dfile > > dpkg-divert --package dash --divert $distrib --add $dfile > > The window when this can happen is very short, and the failure modes > are not so bad (except if ln -sf is interrupted in the middle. That > one would mean no /bin/sh).
To be precise, of course "ln -sf dash /bin/sh" is idempotent; it's just that it's not safe to interrupt it because it works by calling unlink() followed by symlink(). Sorry for the lack of clarify. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
