+# this drives the editor
+sub apply_diff {
+ my ($self, $tree_a, $tree_b) = @_;
+ my @diff_tree = qw(diff-tree -z -r);
+ if ($::_cp_similarity) {
+ push @diff_tree, "-C$::_cp_similarity";
+ } else {
+ push @diff_tree, '-C';
+ }
+ push @diff_tree, '--find-copies-harder' if $::_find_copies_harder;
+ push @diff_tree, "-l$::_l" if defined $::_l;
+ push @diff_tree, $tree_a, $tree_b;
+ my ($diff_fh, $ctx) = command_output_pipe(@diff_tree);
+ my $nl = $/;
+ local $/ = "\0";
+ my $state = 'meta';
+ my @mods;
+ while (<$diff_fh>) {
+ chomp $_; # this gets rid of the trailing "\0"
+ if ($state eq 'meta' && /^:(\d{6})\s(\d{6})\s
+ $::sha1\s($::sha1)\s
+ ([MTCRAD])\d*$/xo) {
+ push @mods, { mode_a => $1, mode_b => $2,
+ sha1_b => $3, chg => $4 };
+ if ($4 =~ /^(?:C|R)$/) {
+ $state = 'file_a';
+ } else {
+ $state = 'file_b';
+ }
+ } elsif ($state eq 'file_a') {
+ my $x = $mods[$#mods] or croak "Empty array\n";
+ if ($x->{chg} !~ /^(?:C|R)$/) {
+ croak "Error parsing $_, $x->{chg}\n";
+ }
+ $x->{file_a} = $_;
+ $state = 'file_b';
+ } elsif ($state eq 'file_b') {
+ my $x = $mods[$#mods] or croak "Empty array\n";
+ if (exists $x->{file_a} && $x->{chg} !~ /^(?:C|R)$/) {
+ croak "Error parsing $_, $x->{chg}\n";
+ }
+ if (!exists $x->{file_a} && $x->{chg} =~ /^(?:C|R)$/) {
+ croak "Error parsing $_, $x->{chg}\n";
+ }
+ $x->{file_b} = $_;
+ $state = 'meta';
+ } else {
+ croak "Error parsing $_\n";
+ }
+ }
+ command_close_pipe($diff_fh, $ctx);
+ $/ = $nl;
+
+ my %o = ( D => 1, R => 0, C => -1, A => 3, M => 3, T => 3 );
+ foreach my $m (sort { $o{$a->{chg}} <=> $o{$b->{chg}} } @mods) {
+ my $f = $m->{chg};
+ if (defined $o{$f}) {
+ $self->$f($m);
+ } else {
+ fatal("Invalid change type: $f\n");
+ }
+ }
+ $self->rmdirs($tree_b) if $::_rmdir;
+ if (@mods == 0) {
+ $self->abort_edit;
+ } else {
+ $self->close_edit;
+ }
+ \@mods;
+}
+