#!/usr/bin/perl -w
# changelog-file -- lintian collector script

# Copyright (C) 1998 Richard Braakman
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, you can find it on the World Wide
# Web at http://www.gnu.org/copyleft/gpl.html, or write to the Free
# Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
# MA 02110-1301, USA.

package Lintian::coll::changelog_file;

use strict;
use warnings;
use autodie;

use File::Copy qw(copy);

use lib "$ENV{'LINTIAN_ROOT'}/lib";
use Lintian::Util qw(fail gunzip_file is_ancestor_of);

sub collect {
    my ($pkg, $type, $dir) = @_;

    unlink("$dir/changelog")
      if -e "$dir/changelog" or -l "$dir/changelog";

    # Extract NEWS.Debian files as well, with similar precautious.
    # Ignore any symlinks to other packages here; in that case, we
    # just won't check the file.
    unlink("$dir/NEWS.Debian")
      if -e "$dir/NEWS.Debian"
      or -l "$dir/NEWS.Debian";

    # Pick the first of these files that exists.
    my @changelogs = (
        "$dir/unpacked/usr/share/doc/$pkg/changelog.Debian.gz",
        "$dir/unpacked/usr/share/doc/$pkg/changelog.Debian",
        "$dir/unpacked/usr/share/doc/$pkg/changelog.debian.gz",
        "$dir/unpacked/usr/share/doc/$pkg/changelog.debian",
        "$dir/unpacked/usr/share/doc/$pkg/changelog.gz",
        "$dir/unpacked/usr/share/doc/$pkg/changelog",
    );

    my $chl;

    if (-d "$dir/unpacked/usr/share/doc/$pkg"
        && !is_ancestor_of("$dir/unpacked", "$dir/unpacked/usr/share/doc/$pkg")
      ) {
        # If the parent dir is outside this package, pretend we didn't find
        # anything.
        return;
    }

    for (@changelogs) {
        if (-l $_ || -f $_) {
            $chl = $_;
            last;
        }
    }

    # If the changelog file we found was a symlink, we have to be
    # careful.  It could be a symlink to some file outside of the
    # laboratory and we don't want to end up reading that file by
    # mistake.  Relative links within the same directory or to a
    # subdirectory we accept; anything else is replaced by an
    # intentinally broken symlink so that checks can do the right
    # thing.
    if (defined($chl) && -l $chl) {
        my $link = readlink($chl);
        if ($link =~ /\.\./
            || ($link =~ m%/% && $link !~ m%^[^/]+(?:/+[^/]+)*\z%)) {
            symlink("$dir/file-is-in-another-package", "$dir/changelog");
            undef $chl;
        } elsif (!-f $chl) {
            undef $chl;
        }
    }

    # If the changelog was a broken symlink, it will be undefined and we'll now
    # treat it the same as if we didn't find a changelog and do nothing.  If it
    # was a symlink, copy the file, since otherwise the relative symlinks are
    # going to break things.
    if (not defined $chl) {
        # no changelog found
    } elsif ($chl =~ /\.gz$/) {
        gunzip_file($chl, "$dir/changelog");
    } elsif (-f $chl && -l $chl) {
        copy($chl, "$dir/changelog") or fail "cannot copy $chl: $!";
    } else {
        link($chl, "$dir/changelog");
    }

    if ($chl && $chl !~ m/changelog\.debian/i) {
        # Either this is a native package OR a non-native package where the
        # debian changelog is missing.  checks/changelog is not too happy
        # with the latter case, so check looks like a Debian changelog.
        open(my $fd, '<', "$dir/changelog");
        my $ok = 0;
        while (my $line = <$fd>) {
            next if $line =~ m/^\s*+$/o;
            # look for something like
            # lintian (2.5.3) UNRELEASED; urgency=low
            if ($line
                =~ m/^\S+\s*\([^\)]+\)\s*(?:UNRELEASED|(?:[^ \t;]+\s*)+)\;/o) {
                $ok = 1;
            }
            last;
        }
        close($fd);
        # Remove it if it not the Debian changelog.
        unlink("$dir/changelog") unless $ok;
    }

    my $news = "$dir/unpacked/usr/share/doc/$pkg/NEWS.Debian.gz";
    if (-f $news) {
        if (-l $news) {
            my $link = readlink($news);
            if ($link =~ /\.\./
                || ($link =~ m%/% && $link !~ m%^[^/]+(?:/+[^/]+)*\z%)) {
                undef $news;
            } elsif (!-f $news) {
                undef $news;
            }
        }
        if ($news) {
            gunzip_file($news, "$dir/NEWS.Debian");
        }
    }

    return;
}

collect(@ARGV) if $0 =~ m,(?:^|/)changelog-file$,;

1;

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