Bug#643009: lintian: check for ISO-2022 encodings

[Jakub Wilk <jwilk@debian.org>]

Package: lintian
Version: 2.5.3
Severity: wishlist
Tags: patch

With the attached patch lintian will detect ISO-2022 encodings in 
copyright files, chanelogs etc.:

$ lintian fdclone_3.00j-2_i386.deb | grep national
W: fdclone: debian-copyright-file-uses-obsolete-national-encoding at line 279

--
Jakub Wilk

diff --git a/lib/Util.pm b/lib/Util.pm
--- a/lib/Util.pm
+++ b/lib/Util.pm
@@ -49,6 +49,7 @@
 	resolve_pkg_path);
 }
 
+use Encode qw();
 use FileHandle;
 use Lintian::Command qw(spawn);
 use Lintian::Output qw(string);
@@ -241,20 +242,26 @@
 	my ($file, $type, $pkg) = @_;
 	my $non_utf8 = 0;
 
-	open (ICONV, '-|', "env LC_ALL=C iconv -f utf8 -t utf8 \Q$file\E 2>&1")
+	open (ICONV, '<', $file)
 	    or fail("failure while checking encoding of $file for $type package $pkg");
-	my $line = 1;
+	my $line = 0;
 	while (<ICONV>) {
-		if (m/iconv: illegal input sequence at position \d+$/) {
-			$non_utf8 = 1;
+		if (m,\e[-!"\$%()*+./],) {
+			# ISO-2022
+			$line = $.;
 			last;
 		}
-		$line++
+		eval {
+			$_ = Encode::decode("UTF-8", $_, Encode::FB_CROAK);
+		};
+		if ($@) {
+			$line = $.;
+			last;
+		}
 	}
 	close ICONV;
 
-	return $line if $non_utf8;
-	return 0;
+	return $line;
 }
 
 # Just like system, except cleanses the environment first to avoid any strange