[thirdparty/git.git] / git-difftool.perl

#!/usr/bin/perl
# Copyright (c) 2009, 2010 David Aguilar
# Copyright (c) 2012 Tim Henigan
#
# This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
# git-difftool--helper script.
#
# This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
# The GIT_DIFF* variables are exported for use by git-difftool--helper.
#
# Any arguments that are unknown to this script are forwarded to 'git diff'.

use 5.008;
use strict;
use warnings;
use Error qw(:try);
use File::Basename qw(dirname);
use File::Copy;
use File::Find;
use File::stat;
use File::Path qw(mkpath rmtree);
use File::Temp qw(tempdir);
use Getopt::Long qw(:config pass_through);
use Git;
use Git::I18N;

sub usage
{
	my $exitcode = shift;
	print << 'USAGE';
usage: git difftool [-t|--tool=<tool>] [--tool-help]
                    [-x|--extcmd=<cmd>]
                    [-g|--gui] [--no-gui]
                    [--prompt] [-y|--no-prompt]
                    [-d|--dir-diff]
                    ['git diff' options]
USAGE
	exit($exitcode);
}

sub print_tool_help
{
	# See the comment at the bottom of file_diff() for the reason behind
	# using system() followed by exit() instead of exec().
	my $rc = system(qw(git mergetool --tool-help=diff));
	exit($rc | ($rc >> 8));
}

sub exit_cleanup
{
	my ($tmpdir, $status) = @_;
	my $errno = $!;
	rmtree($tmpdir);
	if ($status and $errno) {
		my ($package, $file, $line) = caller();
		warn "$file line $line: $errno\n";
	}
	exit($status | ($status >> 8));
}

sub use_wt_file
{
	my ($file, $sha1) = @_;
	my $null_sha1 = '0' x 40;

	if (-l $file || ! -e _) {
		return (0, $null_sha1);
	}

	my $wt_sha1 = Git::command_oneline('hash-object', $file);
	my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
	return ($use, $wt_sha1);
}

sub changed_files
{
	my ($repo_path, $index, $worktree) = @_;
	$ENV{GIT_INDEX_FILE} = $index;

	my @gitargs = ('--git-dir', $repo_path, '--work-tree', $worktree);
	my @refreshargs = (
		@gitargs, 'update-index',
		'--really-refresh', '-q', '--unmerged');
	try {
		Git::command_oneline(@refreshargs);
	} catch Git::Error::Command with {};

	my @diffargs = (@gitargs, 'diff-files', '--name-only', '-z');
	my $line = Git::command_oneline(@diffargs);
	my @files;
	if (defined $line) {
		@files = split('\0', $line);
	} else {
		@files = ();
	}

	delete($ENV{GIT_INDEX_FILE});

	return map { $_ => 1 } @files;
}

sub setup_dir_diff
{
	my ($worktree, $symlinks) = @_;
	my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
	my $diffrtn = Git::command_oneline(@gitargs);
	exit(0) unless defined($diffrtn);

	# Go to the root of the worktree now that we've captured the list of
	# changed files.  The paths returned by diff --raw are relative to the
	# top-level of the repository, but we defer changing directories so
	# that @ARGV can perform pathspec limiting in the current directory.
	chdir($worktree);

	# Build index info for left and right sides of the diff
	my $submodule_mode = '160000';
	my $symlink_mode = '120000';
	my $null_mode = '0' x 6;
	my $null_sha1 = '0' x 40;
	my $lindex = '';
	my $rindex = '';
	my $wtindex = '';
	my %submodule;
	my %symlink;
	my @files = ();
	my %working_tree_dups = ();
	my @rawdiff = split('\0', $diffrtn);

	my $i = 0;
	while ($i < $#rawdiff) {
		if ($rawdiff[$i] =~ /^::/) {
			warn __ <<'EOF';
Combined diff formats ('-c' and '--cc') are not supported in
directory diff mode ('-d' and '--dir-diff').
EOF
			exit(1);
		}

		my ($lmode, $rmode, $lsha1, $rsha1, $status) =
			split(' ', substr($rawdiff[$i], 1));
		my $src_path = $rawdiff[$i + 1];
		my $dst_path;

		if ($status =~ /^[CR]/) {
			$dst_path = $rawdiff[$i + 2];
			$i += 3;
		} else {
			$dst_path = $src_path;
			$i += 2;
		}

		if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
			$submodule{$src_path}{left} = $lsha1;
			if ($lsha1 ne $rsha1) {
				$submodule{$dst_path}{right} = $rsha1;
			} else {
				$submodule{$dst_path}{right} = "$rsha1-dirty";
			}
			next;
		}

		if ($lmode eq $symlink_mode) {
			$symlink{$src_path}{left} =
				Git::command_oneline('show', $lsha1);
		}

		if ($rmode eq $symlink_mode) {
			$symlink{$dst_path}{right} =
				Git::command_oneline('show', $rsha1);
		}

		if ($lmode ne $null_mode and $status !~ /^C/) {
			$lindex .= "$lmode $lsha1\t$src_path\0";
		}

		if ($rmode ne $null_mode) {
			# Avoid duplicate entries
			if ($working_tree_dups{$dst_path}++) {
				next;
			}
			my ($use, $wt_sha1) =
				use_wt_file($dst_path, $rsha1);
			if ($use) {
				push @files, $dst_path;
				$wtindex .= "$rmode $wt_sha1\t$dst_path\0";
			} else {
				$rindex .= "$rmode $rsha1\t$dst_path\0";
			}
		}
	}

	# Go to the root of the worktree so that the left index files
	# are properly setup -- the index is toplevel-relative.
	chdir($worktree);

	# Setup temp directories
	my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
	my $ldir = "$tmpdir/left";
	my $rdir = "$tmpdir/right";
	mkpath($ldir) or exit_cleanup($tmpdir, 1);
	mkpath($rdir) or exit_cleanup($tmpdir, 1);

	# Populate the left and right directories based on each index file
	my ($inpipe, $ctx);
	$ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
	($inpipe, $ctx) =
		Git::command_input_pipe('update-index', '-z', '--index-info');
	print($inpipe $lindex);
	Git::command_close_pipe($inpipe, $ctx);

	my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
	exit_cleanup($tmpdir, $rc) if $rc != 0;

	$ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
	($inpipe, $ctx) =
		Git::command_input_pipe('update-index', '-z', '--index-info');
	print($inpipe $rindex);
	Git::command_close_pipe($inpipe, $ctx);

	$rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
	exit_cleanup($tmpdir, $rc) if $rc != 0;

	$ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
	($inpipe, $ctx) =
		Git::command_input_pipe('update-index', '--info-only', '-z', '--index-info');
	print($inpipe $wtindex);
	Git::command_close_pipe($inpipe, $ctx);

	# If $GIT_DIR was explicitly set just for the update/checkout
	# commands, then it should be unset before continuing.
	delete($ENV{GIT_INDEX_FILE});

	# Changes in the working tree need special treatment since they are
	# not part of the index.
	for my $file (@files) {
		my $dir = dirname($file);
		unless (-d "$rdir/$dir") {
			mkpath("$rdir/$dir") or
			exit_cleanup($tmpdir, 1);
		}
		if ($symlinks) {
			symlink("$worktree/$file", "$rdir/$file") or
			exit_cleanup($tmpdir, 1);
		} else {
			copy($file, "$rdir/$file") or
			exit_cleanup($tmpdir, 1);

			my $mode = stat($file)->mode;
			chmod($mode, "$rdir/$file") or
			exit_cleanup($tmpdir, 1);
		}
	}

	# Changes to submodules require special treatment. This loop writes a
	# temporary file to both the left and right directories to show the
	# change in the recorded SHA1 for the submodule.
	for my $path (keys %submodule) {
		my $ok = 0;
		if (defined($submodule{$path}{left})) {
			$ok = write_to_file("$ldir/$path",
				"Subproject commit $submodule{$path}{left}");
		}
		if (defined($submodule{$path}{right})) {
			$ok = write_to_file("$rdir/$path",
				"Subproject commit $submodule{$path}{right}");
		}
		exit_cleanup($tmpdir, 1) if not $ok;
	}

	# Symbolic links require special treatment. The standard "git diff"
	# shows only the link itself, not the contents of the link target.
	# This loop replicates that behavior.
	for my $path (keys %symlink) {
		my $ok = 0;
		if (defined($symlink{$path}{left})) {
			$ok = write_to_file("$ldir/$path",
					$symlink{$path}{left});
		}
		if (defined($symlink{$path}{right})) {
			$ok = write_to_file("$rdir/$path",
					$symlink{$path}{right});
		}
		exit_cleanup($tmpdir, 1) if not $ok;
	}

	return ($ldir, $rdir, $tmpdir, @files);
}

sub write_to_file
{
	my $path = shift;
	my $value = shift;

	# Make sure the path to the file exists
	my $dir = dirname($path);
	unless (-d "$dir") {
		mkpath("$dir") or return 0;
	}

	# If the file already exists in that location, delete it.  This
	# is required in the case of symbolic links.
	unlink($path);

	open(my $fh, '>', $path) or return 0;
	print($fh $value);
	close($fh);

	return 1;
}

sub main
{
	# parse command-line options. all unrecognized options and arguments
	# are passed through to the 'git diff' command.
	my %opts = (
		difftool_cmd => undef,
		dirdiff => undef,
		extcmd => undef,
		gui => undef,
		help => undef,
		prompt => undef,
		symlinks => $^O ne 'cygwin' &&
				$^O ne 'MSWin32' && $^O ne 'msys',
		tool_help => undef,
		trust_exit_code => undef,
	);
	GetOptions('g|gui!' => \$opts{gui},
		'd|dir-diff' => \$opts{dirdiff},
		'h' => \$opts{help},
		'prompt!' => \$opts{prompt},
		'y' => sub { $opts{prompt} = 0; },
		'symlinks' => \$opts{symlinks},
		'no-symlinks' => sub { $opts{symlinks} = 0; },
		't|tool:s' => \$opts{difftool_cmd},
		'tool-help' => \$opts{tool_help},
		'trust-exit-code' => \$opts{trust_exit_code},
		'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
		'x|extcmd:s' => \$opts{extcmd});

	if (defined($opts{help})) {
		usage(0);
	}
	if (defined($opts{tool_help})) {
		print_tool_help();
	}
	if (defined($opts{difftool_cmd})) {
		if (length($opts{difftool_cmd}) > 0) {
			$ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
		} else {
			print __("No <tool> given for --tool=<tool>\n");
			usage(1);
		}
	}
	if (defined($opts{extcmd})) {
		if (length($opts{extcmd}) > 0) {
			$ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
		} else {
			print __("No <cmd> given for --extcmd=<cmd>\n");
			usage(1);
		}
	}
	if ($opts{gui}) {
		my $guitool = Git::config('diff.guitool');
		if (defined($guitool) && length($guitool) > 0) {
			$ENV{GIT_DIFF_TOOL} = $guitool;
		}
	}

	if (!defined $opts{trust_exit_code}) {
		$opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
	}
	if ($opts{trust_exit_code}) {
		$ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
	} else {
		$ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
	}

	# In directory diff mode, 'git-difftool--helper' is called once
	# to compare the a/b directories.  In file diff mode, 'git diff'
	# will invoke a separate instance of 'git-difftool--helper' for
	# each file that changed.
	if (defined($opts{dirdiff})) {
		dir_diff($opts{extcmd}, $opts{symlinks});
	} else {
		file_diff($opts{prompt});
	}
}

sub dir_diff
{
	my ($extcmd, $symlinks) = @_;
	my $rc;
	my $error = 0;
	my $repo = Git->repository();
	my $repo_path = $repo->repo_path();
	my $worktree = $repo->wc_path();
	$worktree =~ s|/$||; # Avoid double slashes in symlink targets
	my ($a, $b, $tmpdir, @files) = setup_dir_diff($worktree, $symlinks);

	if (defined($extcmd)) {
		$rc = system($extcmd, $a, $b);
	} else {
		$ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
		$rc = system('git', 'difftool--helper', $a, $b);
	}
	# If the diff including working copy files and those
	# files were modified during the diff, then the changes
	# should be copied back to the working tree.
	# Do not copy back files when symlinks are used and the
	# external tool did not replace the original link with a file.
	#
	# These hashes are loaded lazily since they aren't needed
	# in the common case of --symlinks and the difftool updating
	# files through the symlink.
	my %wt_modified;
	my %tmp_modified;
	my $indices_loaded = 0;

	for my $file (@files) {
		next if $symlinks && -l "$b/$file";
		next if ! -f "$b/$file";

		if (!$indices_loaded) {
			%wt_modified = changed_files(
				$repo_path, "$tmpdir/wtindex", $worktree);
			%tmp_modified = changed_files(
				$repo_path, "$tmpdir/wtindex", $b);
			$indices_loaded = 1;
		}

		if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
			warn sprintf(__(
				"warning: Both files modified:\n" .
				"'%s/%s' and '%s/%s'.\n" .
				"warning: Working tree file has been left.\n" .
				"warning:\n"), $worktree, $file, $b, $file);
			$error = 1;
		} elsif (exists $tmp_modified{$file}) {
			my $mode = stat("$b/$file")->mode;
			copy("$b/$file", $file) or
			exit_cleanup($tmpdir, 1);

			chmod($mode, $file) or
			exit_cleanup($tmpdir, 1);
		}
	}
	if ($error) {
		warn sprintf(__(
			"warning: Temporary files exist in '%s'.\n" .
			"warning: You may want to cleanup or recover these.\n"), $tmpdir);
		exit(1);
	} else {
		exit_cleanup($tmpdir, $rc);
	}
}

sub file_diff
{
	my ($prompt) = @_;

	if (defined($prompt)) {
		if ($prompt) {
			$ENV{GIT_DIFFTOOL_PROMPT} = 'true';
		} else {
			$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
		}
	}

	$ENV{GIT_PAGER} = '';
	$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';

	# ActiveState Perl for Win32 does not implement POSIX semantics of
	# exec* system call. It just spawns the given executable and finishes
	# the starting program, exiting with code 0.
	# system will at least catch the errors returned by git diff,
	# allowing the caller of git difftool better handling of failures.
	my $rc = system('git', 'diff', @ARGV);
	exit($rc | ($rc >> 8));
}

main();
Commit	Line	Data
7e0abcec	1	#!/usr/bin/perl
f47f1e2c	2	# Copyright (c) 2009, 2010 David Aguilar
7e0abcec	3	# Copyright (c) 2012 Tim Henigan
5c38ea31 DA	4	#
5c38ea31 DA	5	# This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
a904392e DA	6	# git-difftool--helper script.
	7	#
	8	# This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
7e0abcec	9	# The GIT_DIFF* variables are exported for use by git-difftool--helper.
a904392e	10	#
5c38ea31 DA	11	# Any arguments that are unknown to this script are forwarded to 'git diff'.
5c38ea31 DA	12
d48b2841	13	use 5.008;
5c38ea31 DA	14	use strict;
5c38ea31 DA	15	use warnings;
67aa147a	16	use Error qw(:try);
7c7584b9	17	use File::Basename qw(dirname);
7e0abcec	18	use File::Copy;
7c7584b9	19	use File::Find;
7e0abcec	20	use File::stat;
ceb1497a	21	use File::Path qw(mkpath rmtree);
7e0abcec	22	use File::Temp qw(tempdir);
3f94ff75 TH	23	use Getopt::Long qw(:config pass_through);
3f94ff75 TH	24	use Git;
a948ebac	25	use Git::I18N;
5c38ea31 DA	26
	27	sub usage
	28	{
28360769	29	my $exitcode = shift;
5c38ea31	30	print << 'USAGE';
bf73fc21	31	usage: git difftool [-t\|--tool=<tool>] [--tool-help]
85089604 TH	32	[-x\|--extcmd=<cmd>]
85089604 TH	33	[-g\|--gui] [--no-gui]
3f94ff75	34	[--prompt] [-y\|--no-prompt]
7e0abcec	35	[-d\|--dir-diff]
f47f1e2c	36	['git diff' options]
5c38ea31	37	USAGE
28360769	38	exit($exitcode);
5c38ea31 DA	39	}
5c38ea31 DA	40
bf73fc21 TH	41	sub print_tool_help
bf73fc21 TH	42	{
abaf175c JK	43	# See the comment at the bottom of file_diff() for the reason behind
abaf175c JK	44	# using system() followed by exit() instead of exec().
4fb4b02d	45	my $rc = system(qw(git mergetool --tool-help=diff));
abaf175c	46	exit($rc \| ($rc >> 8));
bf73fc21 TH	47	}
bf73fc21 TH	48
ceb1497a DA	49	sub exit_cleanup
	50	{
	51	my ($tmpdir, $status) = @_;
	52	my $errno = $!;
	53	rmtree($tmpdir);
	54	if ($status and $errno) {
	55	my ($package, $file, $line) = caller();
	56	warn "$file line $line: $errno\n";
	57	}
	58	exit($status \| ($status >> 8));
	59	}
	60
02c56314 JK	61	sub use_wt_file
02c56314 JK	62	{
f242a03d	63	my ($file, $sha1) = @_;
02c56314 JK	64	my $null_sha1 = '0' x 40;
02c56314 JK	65
f242a03d	66	if (-l $file \|\| ! -e _) {
1f197a1d JK	67	return (0, $null_sha1);
	68	}
	69
f242a03d	70	my $wt_sha1 = Git::command_oneline('hash-object', $file);
67aa147a JK	71	my $use = ($sha1 eq $null_sha1) \|\| ($sha1 eq $wt_sha1);
	72	return ($use, $wt_sha1);
	73	}
	74
	75	sub changed_files
	76	{
	77	my ($repo_path, $index, $worktree) = @_;
	78	$ENV{GIT_INDEX_FILE} = $index;
67aa147a	79
98f917ed DA	80	my @gitargs = ('--git-dir', $repo_path, '--work-tree', $worktree);
	81	my @refreshargs = (
	82	@gitargs, 'update-index',
	83	'--really-refresh', '-q', '--unmerged');
67aa147a JK	84	try {
	85	Git::command_oneline(@refreshargs);
	86	} catch Git::Error::Command with {};
	87
98f917ed DA	88	my @diffargs = (@gitargs, 'diff-files', '--name-only', '-z');
98f917ed DA	89	my $line = Git::command_oneline(@diffargs);
67aa147a JK	90	my @files;
	91	if (defined $line) {
	92	@files = split('\0', $line);
	93	} else {
	94	@files = ();
	95	}
	96
	97	delete($ENV{GIT_INDEX_FILE});
67aa147a JK	98
67aa147a JK	99	return map { $_ => 1 } @files;
02c56314 JK	100	}
02c56314 JK	101
7e0abcec TH	102	sub setup_dir_diff
7e0abcec TH	103	{
ce692697	104	my ($worktree, $symlinks) = @_;
a4cd5be3	105	my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
32b8c581	106	my $diffrtn = Git::command_oneline(@gitargs);
ed36e5bd	107	exit(0) unless defined($diffrtn);
7e0abcec	108
f242a03d DA	109	# Go to the root of the worktree now that we've captured the list of
	110	# changed files. The paths returned by diff --raw are relative to the
	111	# top-level of the repository, but we defer changing directories so
	112	# that @ARGV can perform pathspec limiting in the current directory.
ce692697	113	chdir($worktree);
f242a03d	114
7e0abcec TH	115	# Build index info for left and right sides of the diff
	116	my $submodule_mode = '160000';
	117	my $symlink_mode = '120000';
	118	my $null_mode = '0' x 6;
	119	my $null_sha1 = '0' x 40;
	120	my $lindex = '';
	121	my $rindex = '';
67aa147a	122	my $wtindex = '';
7e0abcec TH	123	my %submodule;
7e0abcec TH	124	my %symlink;
ce692697	125	my @files = ();
366f9cea	126	my %working_tree_dups = ();
7e0abcec TH	127	my @rawdiff = split('\0', $diffrtn);
	128
	129	my $i = 0;
	130	while ($i < $#rawdiff) {
	131	if ($rawdiff[$i] =~ /^::/) {
a948ebac	132	warn __ <<'EOF';
a4cd5be3 DA	133	Combined diff formats ('-c' and '--cc') are not supported in
	134	directory diff mode ('-d' and '--dir-diff').
	135	EOF
7e0abcec TH	136	exit(1);
	137	}
	138
a4cd5be3 DA	139	my ($lmode, $rmode, $lsha1, $rsha1, $status) =
a4cd5be3 DA	140	split(' ', substr($rawdiff[$i], 1));
7e0abcec TH	141	my $src_path = $rawdiff[$i + 1];
	142	my $dst_path;
	143
	144	if ($status =~ /^[CR]/) {
	145	$dst_path = $rawdiff[$i + 2];
	146	$i += 3;
	147	} else {
	148	$dst_path = $src_path;
	149	$i += 2;
	150	}
	151
a4cd5be3	152	if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
7e0abcec TH	153	$submodule{$src_path}{left} = $lsha1;
	154	if ($lsha1 ne $rsha1) {
	155	$submodule{$dst_path}{right} = $rsha1;
	156	} else {
	157	$submodule{$dst_path}{right} = "$rsha1-dirty";
	158	}
	159	next;
	160	}
	161
	162	if ($lmode eq $symlink_mode) {
a4cd5be3	163	$symlink{$src_path}{left} =
32b8c581	164	Git::command_oneline('show', $lsha1);
7e0abcec TH	165	}
	166
	167	if ($rmode eq $symlink_mode) {
a4cd5be3	168	$symlink{$dst_path}{right} =
32b8c581	169	Git::command_oneline('show', $rsha1);
7e0abcec TH	170	}
7e0abcec TH	171
a4cd5be3	172	if ($lmode ne $null_mode and $status !~ /^C/) {
7e0abcec TH	173	$lindex .= "$lmode $lsha1\t$src_path\0";
	174	}
	175
	176	if ($rmode ne $null_mode) {
ce692697	177	# Avoid duplicate entries
366f9cea DA	178	if ($working_tree_dups{$dst_path}++) {
	179	next;
	180	}
32b8c581	181	my ($use, $wt_sha1) =
f242a03d	182	use_wt_file($dst_path, $rsha1);
67aa147a	183	if ($use) {
ce692697	184	push @files, $dst_path;
67aa147a	185	$wtindex .= "$rmode $wt_sha1\t$dst_path\0";
02c56314 JK	186	} else {
02c56314 JK	187	$rindex .= "$rmode $rsha1\t$dst_path\0";
7e0abcec TH	188	}
	189	}
	190	}
	191
853e10c1 DA	192	# Go to the root of the worktree so that the left index files
853e10c1 DA	193	# are properly setup -- the index is toplevel-relative.
5a5d3f1f	194	chdir($worktree);
853e10c1	195
ceb1497a DA	196	# Setup temp directories
	197	my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
	198	my $ldir = "$tmpdir/left";
	199	my $rdir = "$tmpdir/right";
	200	mkpath($ldir) or exit_cleanup($tmpdir, 1);
	201	mkpath($rdir) or exit_cleanup($tmpdir, 1);
	202
7e0abcec TH	203	# Populate the left and right directories based on each index file
	204	my ($inpipe, $ctx);
	205	$ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
a4cd5be3	206	($inpipe, $ctx) =
32b8c581	207	Git::command_input_pipe('update-index', '-z', '--index-info');
7e0abcec	208	print($inpipe $lindex);
32b8c581	209	Git::command_close_pipe($inpipe, $ctx);
ceb1497a	210
75cd7583	211	my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
ceb1497a	212	exit_cleanup($tmpdir, $rc) if $rc != 0;
7e0abcec TH	213
7e0abcec TH	214	$ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
a4cd5be3	215	($inpipe, $ctx) =
32b8c581	216	Git::command_input_pipe('update-index', '-z', '--index-info');
7e0abcec	217	print($inpipe $rindex);
32b8c581	218	Git::command_close_pipe($inpipe, $ctx);
ceb1497a	219
7e0abcec	220	$rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
ceb1497a	221	exit_cleanup($tmpdir, $rc) if $rc != 0;
7e0abcec	222
67aa147a JK	223	$ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
67aa147a JK	224	($inpipe, $ctx) =
32b8c581	225	Git::command_input_pipe('update-index', '--info-only', '-z', '--index-info');
67aa147a	226	print($inpipe $wtindex);
32b8c581	227	Git::command_close_pipe($inpipe, $ctx);
67aa147a	228
7e0abcec TH	229	# If $GIT_DIR was explicitly set just for the update/checkout
7e0abcec TH	230	# commands, then it should be unset before continuing.
7e0abcec TH	231	delete($ENV{GIT_INDEX_FILE});
	232
	233	# Changes in the working tree need special treatment since they are
e6e3e2a6	234	# not part of the index.
ce692697	235	for my $file (@files) {
7e0abcec TH	236	my $dir = dirname($file);
7e0abcec TH	237	unless (-d "$rdir/$dir") {
ceb1497a DA	238	mkpath("$rdir/$dir") or
ceb1497a DA	239	exit_cleanup($tmpdir, 1);
7e0abcec	240	}
1f229345	241	if ($symlinks) {
ce692697	242	symlink("$worktree/$file", "$rdir/$file") or
ceb1497a	243	exit_cleanup($tmpdir, 1);
1f229345	244	} else {
f242a03d	245	copy($file, "$rdir/$file") or
ceb1497a DA	246	exit_cleanup($tmpdir, 1);
ceb1497a DA	247
f242a03d	248	my $mode = stat($file)->mode;
ceb1497a DA	249	chmod($mode, "$rdir/$file") or
ceb1497a DA	250	exit_cleanup($tmpdir, 1);
1f229345	251	}
7e0abcec TH	252	}
	253
	254	# Changes to submodules require special treatment. This loop writes a
	255	# temporary file to both the left and right directories to show the
	256	# change in the recorded SHA1 for the submodule.
	257	for my $path (keys %submodule) {
951b551d	258	my $ok = 0;
7e0abcec	259	if (defined($submodule{$path}{left})) {
ceb1497a DA	260	$ok = write_to_file("$ldir/$path",
ceb1497a DA	261	"Subproject commit $submodule{$path}{left}");
7e0abcec TH	262	}
7e0abcec TH	263	if (defined($submodule{$path}{right})) {
ceb1497a DA	264	$ok = write_to_file("$rdir/$path",
ceb1497a DA	265	"Subproject commit $submodule{$path}{right}");
7e0abcec	266	}
ceb1497a	267	exit_cleanup($tmpdir, 1) if not $ok;
7e0abcec TH	268	}
	269
	270	# Symbolic links require special treatment. The standard "git diff"
	271	# shows only the link itself, not the contents of the link target.
	272	# This loop replicates that behavior.
	273	for my $path (keys %symlink) {
951b551d	274	my $ok = 0;
7e0abcec	275	if (defined($symlink{$path}{left})) {
ceb1497a DA	276	$ok = write_to_file("$ldir/$path",
ceb1497a DA	277	$symlink{$path}{left});
7e0abcec TH	278	}
7e0abcec TH	279	if (defined($symlink{$path}{right})) {
ceb1497a DA	280	$ok = write_to_file("$rdir/$path",
ceb1497a DA	281	$symlink{$path}{right});
7e0abcec	282	}
ceb1497a	283	exit_cleanup($tmpdir, 1) if not $ok;
7e0abcec TH	284	}
7e0abcec TH	285
ce692697	286	return ($ldir, $rdir, $tmpdir, @files);
7e0abcec TH	287	}
	288
	289	sub write_to_file
	290	{
	291	my $path = shift;
	292	my $value = shift;
	293
	294	# Make sure the path to the file exists
	295	my $dir = dirname($path);
	296	unless (-d "$dir") {
ceb1497a	297	mkpath("$dir") or return 0;
7e0abcec TH	298	}
	299
	300	# If the file already exists in that location, delete it. This
	301	# is required in the case of symbolic links.
ceb1497a	302	unlink($path);
7e0abcec	303
ceb1497a	304	open(my $fh, '>', $path) or return 0;
7e0abcec TH	305	print($fh $value);
7e0abcec TH	306	close($fh);
ceb1497a DA	307
ceb1497a DA	308	return 1;
7e0abcec TH	309	}
7e0abcec TH	310
75cd7583 DA	311	sub main
	312	{
	313	# parse command-line options. all unrecognized options and arguments
	314	# are passed through to the 'git diff' command.
c9bdd505 DA	315	my %opts = (
	316	difftool_cmd => undef,
	317	dirdiff => undef,
	318	extcmd => undef,
	319	gui => undef,
	320	help => undef,
	321	prompt => undef,
190f5475 DA	322	symlinks => $^O ne 'cygwin' &&
190f5475 DA	323	$^O ne 'MSWin32' && $^O ne 'msys',
c9bdd505	324	tool_help => undef,
2b52123f	325	trust_exit_code => undef,
c9bdd505 DA	326	);
	327	GetOptions('g\|gui!' => \$opts{gui},
	328	'd\|dir-diff' => \$opts{dirdiff},
	329	'h' => \$opts{help},
	330	'prompt!' => \$opts{prompt},
	331	'y' => sub { $opts{prompt} = 0; },
1f229345 DA	332	'symlinks' => \$opts{symlinks},
1f229345 DA	333	'no-symlinks' => sub { $opts{symlinks} = 0; },
c9bdd505 DA	334	't\|tool:s' => \$opts{difftool_cmd},
c9bdd505 DA	335	'tool-help' => \$opts{tool_help},
2b52123f DA	336	'trust-exit-code' => \$opts{trust_exit_code},
2b52123f DA	337	'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
c9bdd505 DA	338	'x\|extcmd:s' => \$opts{extcmd});
	339
	340	if (defined($opts{help})) {
75cd7583	341	usage(0);
5c38ea31	342	}
c9bdd505	343	if (defined($opts{tool_help})) {
75cd7583	344	print_tool_help();
3f94ff75	345	}
c9bdd505 DA	346	if (defined($opts{difftool_cmd})) {
	347	if (length($opts{difftool_cmd}) > 0) {
	348	$ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
75cd7583	349	} else {
a948ebac	350	print __("No <tool> given for --tool=<tool>\n");
75cd7583 DA	351	usage(1);
	352	}
	353	}
c9bdd505 DA	354	if (defined($opts{extcmd})) {
	355	if (length($opts{extcmd}) > 0) {
	356	$ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
75cd7583	357	} else {
a948ebac	358	print __("No <cmd> given for --extcmd=<cmd>\n");
75cd7583 DA	359	usage(1);
	360	}
	361	}
c9bdd505 DA	362	if ($opts{gui}) {
c9bdd505 DA	363	my $guitool = Git::config('diff.guitool');
af14b5cf	364	if (defined($guitool) && length($guitool) > 0) {
75cd7583 DA	365	$ENV{GIT_DIFF_TOOL} = $guitool;
	366	}
	367	}
	368
2b52123f DA	369	if (!defined $opts{trust_exit_code}) {
	370	$opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
	371	}
	372	if ($opts{trust_exit_code}) {
	373	$ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
	374	} else {
	375	$ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
	376	}
	377
75cd7583 DA	378	# In directory diff mode, 'git-difftool--helper' is called once
	379	# to compare the a/b directories. In file diff mode, 'git diff'
	380	# will invoke a separate instance of 'git-difftool--helper' for
	381	# each file that changed.
c9bdd505	382	if (defined($opts{dirdiff})) {
1f229345	383	dir_diff($opts{extcmd}, $opts{symlinks});
75cd7583	384	} else {
c9bdd505	385	file_diff($opts{prompt});
3f94ff75 TH	386	}
3f94ff75 TH	387	}
7e0abcec	388
75cd7583 DA	389	sub dir_diff
75cd7583 DA	390	{
1f229345	391	my ($extcmd, $symlinks) = @_;
75cd7583	392	my $rc;
ceb1497a	393	my $error = 0;
75cd7583	394	my $repo = Git->repository();
32b8c581	395	my $repo_path = $repo->repo_path();
ce692697 DA	396	my $worktree = $repo->wc_path();
	397	$worktree =~ s\|/$\|\|; # Avoid double slashes in symlink targets
	398	my ($a, $b, $tmpdir, @files) = setup_dir_diff($worktree, $symlinks);
ceb1497a	399
7e0abcec TH	400	if (defined($extcmd)) {
7e0abcec TH	401	$rc = system($extcmd, $a, $b);
3f94ff75	402	} else {
7e0abcec TH	403	$ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
7e0abcec TH	404	$rc = system('git', 'difftool--helper', $a, $b);
d531174f	405	}
7e0abcec TH	406	# If the diff including working copy files and those
7e0abcec TH	407	# files were modified during the diff, then the changes
1f229345 DA	408	# should be copied back to the working tree.
	409	# Do not copy back files when symlinks are used and the
	410	# external tool did not replace the original link with a file.
67aa147a JK	411	#
	412	# These hashes are loaded lazily since they aren't needed
	413	# in the common case of --symlinks and the difftool updating
	414	# files through the symlink.
	415	my %wt_modified;
	416	my %tmp_modified;
	417	my $indices_loaded = 0;
	418
ce692697	419	for my $file (@files) {
1f229345	420	next if $symlinks && -l "$b/$file";
283abb2c DA	421	next if ! -f "$b/$file";
283abb2c DA	422
67aa147a	423	if (!$indices_loaded) {
32b8c581	424	%wt_modified = changed_files(
ce692697	425	$repo_path, "$tmpdir/wtindex", $worktree);
32b8c581 DA	426	%tmp_modified = changed_files(
32b8c581 DA	427	$repo_path, "$tmpdir/wtindex", $b);
67aa147a JK	428	$indices_loaded = 1;
	429	}
	430
	431	if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
a948ebac VA	432	warn sprintf(__(
	433	"warning: Both files modified:\n" .
	434	"'%s/%s' and '%s/%s'.\n" .
	435	"warning: Working tree file has been left.\n" .
5a5d3f1f	436	"warning:\n"), $worktree, $file, $b, $file);
ceb1497a	437	$error = 1;
67aa147a	438	} elsif (exists $tmp_modified{$file}) {
1f229345	439	my $mode = stat("$b/$file")->mode;
f242a03d	440	copy("$b/$file", $file) or
ceb1497a DA	441	exit_cleanup($tmpdir, 1);
ceb1497a DA	442
f242a03d	443	chmod($mode, $file) or
ceb1497a	444	exit_cleanup($tmpdir, 1);
05df5326	445	}
7e0abcec	446	}
ceb1497a	447	if ($error) {
a948ebac VA	448	warn sprintf(__(
	449	"warning: Temporary files exist in '%s'.\n" .
	450	"warning: You may want to cleanup or recover these.\n"), $tmpdir);
ceb1497a DA	451	exit(1);
	452	} else {
	453	exit_cleanup($tmpdir, $rc);
	454	}
75cd7583 DA	455	}
	456
	457	sub file_diff
	458	{
	459	my ($prompt) = @_;
	460
7e0abcec TH	461	if (defined($prompt)) {
	462	if ($prompt) {
	463	$ENV{GIT_DIFFTOOL_PROMPT} = 'true';
	464	} else {
	465	$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
	466	}
	467	}
	468
	469	$ENV{GIT_PAGER} = '';
	470	$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
	471
	472	# ActiveState Perl for Win32 does not implement POSIX semantics of
	473	# exec* system call. It just spawns the given executable and finishes
	474	# the starting program, exiting with code 0.
	475	# system will at least catch the errors returned by git diff,
	476	# allowing the caller of git difftool better handling of failures.
	477	my $rc = system('git', 'diff', @ARGV);
	478	exit($rc \| ($rc >> 8));
	479	}
75cd7583 DA	480
75cd7583 DA	481	main();