[Pkg-clamav-devel] Bug#592322: Bug#592322: freshclam.conf: update moves DatabaseMirror line

[Stephen Gran]

This one time, at band camp, Török Edwin said:
> On Mon, 9 Aug 2010 12:55:32 +0100
> Stephen Gran <sgran at debian.org> wrote:
> 
> > This one time, at band camp, Török Edwin said:
> > > After updating clamav-freshclam I got this diff:
> > > --- /etc/clamav/freshclam.conf 2010-06-10 15:40:04.624888178 +0300
> > > +++ /var/lib/clamav/freshclam.conf 2010-08-09 12:03:46.265177327
> > > +0300
> > 
> > I agree this is most likely a bug - we're probably not popping off the
> > list in the same order we push onto it or something.
> > 
> > However:
> > 
> > > -- Package-specific info:
> > > --- configuration ---
> > > Checking configuration files in /usr/local/etc
> > 
> > Can you try without local versions installed, just to make sure
> > nothing funny is happening as a result?
> 
> Well I can't reproduce this with an apt-get --reinstall
> clamav-freshclam.
> 
> What should I do to try and reproduce this bug? Revert to older
> clamav-freshclam then upgrade again?

Just eliminating the local version, and running
dpkg-reconfigure -phigh clamav-freshclam
once or twice should do it.

Although, looking at the way the list is set up, I can see that we are
in fact setting it up wrong:

We set up the variable:

  if [ -e "$CLAMAVCONF" ]; then
    for variable in `egrep -v '^[[:space:]]*(#|$)' "$CLAMAVCONF" | awk '{print $1}'`; do
      case "$variable" in
        DatabaseMirror)
        if [ -z "$DatabaseMirror" ]; then
          for i in `grep ^$variable $CLAMAVCONF | awk '{print $2}'`; do
            value="$i $value"
          done
        else
          continue
        fi
        ;;

Then store that in debconf:

if [ -n "$DatabaseMirror" ]; then
  if [ -e /usr/share/doc/clamav-freshclam/mirror-list.gz ]; then
    if zgrep -q "$DatabaseMirror" /usr/share/doc/clamav-freshclam/mirror-list.gz;then
      db_set clamav-freshclam/local_mirror `zgrep "$DatabaseMirror" /usr/share/doc/clamav-freshclam/mirror-list.gz` || true
    else
      db_set clamav-freshclam/local_mirror "$DatabaseMirror" || true
    fi
  fi
fi

Then pull it out to construct the config file:

  db_metaget clamav-freshclam/local_mirror value || true
  [ "$RET" = "" ] || rawmirrors="$RET"
  if echo "$rawmirrors" | egrep -q '(\(|\))'; then
    mirrors=`echo "$rawmirrors" | awk '{print $1}'`
  else
    mirrors="$rawmirrors"
  fi

And then finally write out the temporary copy of the config file:
  if [ -n "$mirrors" ]; then
    for i in $mirrors; do
      echo "DatabaseMirror $i" >> $DEBCONFILE
    done
  fi
  if ! echo "$mirrors" | grep -q database.clamav.net; then
    echo "DatabaseMirror database.clamav.net" >> $DEBCONFILE
  fi
  if [ -n "$DatabaseMirror" ]; then
    for m in $DatabaseMirror; do
      grep -q "$m" "$DEBCONFILE" || echo "DatabaseMirror $m" >> $DEBCONFILE
    done
  fi

So it looks like the simple fix will be to change:
value="$i $value"
to
value="$value $i"

in /var/lib/dpkg/info/clamav-freshclam.config and 
/var/lib/dpkg/info/clamav-freshclam.postinst

If the naive first try of dpkg-reconfigure still does the wrong thing
for you after removing the local copy, can you try this fix and let me
know if it does the right thing?  I suspect that's all that's needed,
but as you have a handy test case, it would be useful to confirm it.

My fear is that it will be a more subtle bug with the way we are using
debconf to store the data (that the template expects a single value, and
we are potentially storing a space seperated multi-value list, some of
which aren't in the debconf list of things to pick from).  If the above
simple case doesn't fix it for you, I may ask you to do some more set -x
debugging to confirm that.

Cheers,
-- 
 -----------------------------------------------------------------
|   ,''`.                                            Stephen Gran |
|  : :' :                                        sgran at debian.org |
|  `. `'                        Debian user, admin, and developer |
|    `-                                     http://www.debian.org |
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