Bug#435656: Change in behaviour of gzreadline() caused debmirror to delete my whole mirror

[Peter Baumann]

On Fri, Aug 03, 2007 at 08:23:10AM +0300, Damyan Ivanov wrote:
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> - -=| Peter Baumann,  2.08.2007 14:55 |=-
> > 
> > After the upgrade to version 2.005-1 debmirror decided to delete my
> > whole debian mirror. And as i didn't pay attention during debmirror
> > updates this is really annoying.
> > 
> > The corresponding debmirror code is here:
> > 
> >  851     my $gunzf = gzopen($file, "rb") or die "$file: $!";
> >  852     my $line;
> >  853     my $res;
> >  854     my $loop = 1;
> >  855     while ($loop) {
> >  856       my $buf = "";
> >  857       while(($res = $gunzf->gzreadline($line) > 0)
> >  858             && !($line =~ /^$/)) {
> >  859         $buf = $buf . $line;
> >  860       }
> >  861       if ($res <= 0) { # <--------  THIS IS ALWAYS TRUE AFTER THE UPGRADE
> >  862         $loop = 0;
> >  863         next;
> >  864       }
> 
> I have a couple of guesses that you may help with:
> 
> The code above reads until either an empty $line appears, or $res is not
> positive. Could it be possible that the file in question does no contain
> empty lines and thus the inner while reads until EOF?
> 
> Or, perhaps $line needs a chomp in order to match /^$/ ?
> (yes, that would mean a behaviour change)

No. The file is fine (it is e.g dists/lenny/main/binary-i386/Packages.gz).
But this gave me the right direction. Here is the output of the slighly
changed code segment (output enclosed by '-' markers)

    my $gunzf = gzopen($file, "rb") or die "$file: $!";
    my $line;
    my $res;
    my $loop = 1;
    while ($loop) {
      my $buf = "";
      while(($res = $gunzf->gzreadline($line) > 0)
           && !($line =~ /^$/)) {
        printf "%u:%s", length($line), $line;
        exit;
        $buf = $buf . $line;
      }



previous version (1.42-2):
-
16:Package: 2vcard
-


new version (2.005-1)
-
791:Package: 2vcard
Priority: optional
Section: utils
Installed-Size: 108
Maintainer: Martin Albisetti <argentina at gmail.com>
Architecture: i386
Version: 0.5-1
Filename: pool/main/2/2vcard/2vcard_0.5-1_i386.deb
Size: 14090
MD5sum: 074de92c99657c98dff1ed42d580f84b
SHA1: ceea35694c35437ad3f8a1e06ab7d3e698efee56
SHA256: 814b27ae828b9947d63a1ce628c85e5fb36f95075f3ccdbd23c9c908e067fb6c
Description: A little perl script to convert an addressbook to VCARD file format
 2vcard is a little perl script that you can use to convert the popular vcard
 file format. Currently 2vcard can only convert adressbooks and alias files from
 the following formats: abook,eudora,juno,ldif,mutt,mh and pine.
 .
 The VCARD format is used by gnomecard, for example, which is turn is used by
 the balsa email client.

-

So it is definitly a change in behaviour of gzreadline()

Greetings,
Peter Baumann