- open my $fd, "-|", "$gitbin/diff-tree", "-r", $parent, $hash;
+ open my $fd, "-|", "$gitbin/cat-file", "commit", $hash;
+ my $tree = <$fd>;
+ chomp $tree;
+ $tree =~ s/tree //;
+ close $fd;
+
+ open $fd, "-|", "$gitbin/cat-file", "commit", $parent;
+ my $parent_tree = <$fd>;
+ chomp $parent_tree;
+ $parent_tree =~ s/tree //;
+ close $fd;
+
+ open $fd, "-|", "$gitbin/diff-tree", "-r", $parent_tree, $tree;