Bug#944964: dh-make-perl: Module accesses internal dpkg database

[gregor herrmann]

On Sun, 17 Nov 2019 21:38:24 +0100, Guillem Jover wrote:

>  [M] lib/Debian/DpkgLists.pm
> 
> The function _cat_lists() accesses the file list files directly, and
> should be switched to use either «dpkg-query --listfiles» instead, or the
> dpkg-query db-fsys:Files virtual field with --show.

Thanks for the bug report and the hint about db-fsys:Files.

I've now come up with a first patch (pushed to git) which seems to
work and which is not terribly slow.

t/DpkgLists.t still passes and takes ~9 seconds; with the original
_cat_lists() it was more like 2.5 seconds but well.


For convenience, here's the current proposal for _cat_lists():

#v+
sub _cat_lists
{
    my ( $class, $callback ) = @_;
    my $query_list = 'dpkg-query --show --showformat "\${Package}\n\${db-fsys:Files}"';
    open( my $fh, '-|', $query_list )
        or warn "failed to run dpkg-query: $!\n";
    my ( $pkg, $filename );
    while ( defined( my $line = <$fh> ) ) {
        chomp $line;
        if ( $line =~ /^[a-z0-9]/ ) {    # package names start in first column
            $pkg = $line;
            next;
        }
        elsif ( $line =~ /^ \// ) {      # filenames have a leading space
            ( $filename = $line ) =~ s/^\s+//;
        }
        else {
            warn "Unrecognized line '$line'\n";
            next;
        }
        &$callback( $pkg, $filename );
    }
    close($fh);
}
#v-

I wait a bit for comments or improvements before uploading.


Cheers,
gregor

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