From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 19 Jan 2017 20:30:40 +0000 (+0100)
Subject: difftool: retire the scripted version
X-Git-Tag: v2.12.0-rc0~28^2~1
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/019678d6b1f83419cdc35e3d455175adce3a379c?hp=--cc

difftool: retire the scripted version

It served its purpose, but now we have a builtin difftool. Time for the
Perl script to enjoy Florida.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

019678d6b1f83419cdc35e3d455175adce3a379c
diff --git a/.gitignore b/.gitignore
index f96e50ed40..05cb58a3d4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -76,7 +76,6 @@
 /git-init-db
 /git-interpret-trailers
 /git-instaweb
-/git-legacy-difftool
 /git-log
 /git-ls-files
 /git-ls-remote
diff --git a/Makefile b/Makefile
index 7863bc2f3d..28b6440b3c 100644
--- a/Makefile
+++ b/Makefile
@@ -527,7 +527,6 @@ SCRIPT_LIB += git-sh-setup
 SCRIPT_LIB += git-sh-i18n
 
 SCRIPT_PERL += git-add--interactive.perl
-SCRIPT_PERL += git-legacy-difftool.perl
 SCRIPT_PERL += git-archimport.perl
 SCRIPT_PERL += git-cvsexportcommit.perl
 SCRIPT_PERL += git-cvsimport.perl
diff --git a/builtin/difftool.c b/builtin/difftool.c
index 2115e548a5..42ad9e804a 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -616,30 +616,6 @@ static int run_file_diff(int prompt, const char *prefix,
 	exit(ret);
 }
 
-/*
- * NEEDSWORK: this function can go once the legacy-difftool Perl script is
- * retired.
- *
- * We intentionally avoid reading the config directly here, to avoid messing up
- * the GIT_* environment variables when we need to fall back to exec()ing the
- * Perl script.
- */
-static int use_builtin_difftool(void) {
-	struct child_process cp = CHILD_PROCESS_INIT;
-	struct strbuf out = STRBUF_INIT;
-	int ret;
-
-	argv_array_pushl(&cp.args,
-			 "config", "--bool", "difftool.usebuiltin", NULL);
-	cp.git_cmd = 1;
-	if (capture_command(&cp, &out, 6))
-		return 0;
-	strbuf_trim(&out);
-	ret = !strcmp("true", out.buf);
-	strbuf_release(&out);
-	return ret;
-}
-
 int cmd_difftool(int argc, const char **argv, const char *prefix)
 {
 	int use_gui_tool = 0, dir_diff = 0, prompt = -1, symlinks = 0,
@@ -671,23 +647,6 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	/*
-	 * NEEDSWORK: Once the builtin difftool has been tested enough
-	 * and git-legacy-difftool.perl is retired to contrib/, this preamble
-	 * can be removed.
-	 */
-	if (!use_builtin_difftool()) {
-		const char *path = mkpath("%s/git-legacy-difftool",
-					  git_exec_path());
-
-		if (sane_execvp(path, (char **)argv) < 0)
-			die_errno("could not exec %s", path);
-
-		return 0;
-	}
-	prefix = setup_git_directory();
-	trace_repo_setup(prefix);
-	setup_work_tree();
 	/* NEEDSWORK: once we no longer spawn anything, remove this */
 	setenv(GIT_DIR_ENVIRONMENT, absolute_path(get_git_dir()), 1);
 	setenv(GIT_WORK_TREE_ENVIRONMENT, absolute_path(get_git_work_tree()), 1);
diff --git a/contrib/examples/git-difftool.perl b/contrib/examples/git-difftool.perl
new file mode 100755
index 0000000000..a5790d03a0
--- /dev/null
+++ b/contrib/examples/git-difftool.perl
@@ -0,0 +1,470 @@
+#!/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;
+
+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 | ($status >> 8));
+}
+
+sub use_wt_file
+{
+	my ($workdir, $file, $sha1) = @_;
+	my $null_sha1 = '0' x 40;
+
+	if (-l "$workdir/$file" || ! -e _) {
+		return (0, $null_sha1);
+	}
+
+	my $wt_sha1 = Git::command_oneline('hash-object', "$workdir/$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 { $_ => 1 } @files;
+}
+
+sub setup_dir_diff
+{
+	my ($workdir, $symlinks) = @_;
+	my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
+	my $diffrtn = Git::command_oneline(@gitargs);
+	exit(0) unless defined($diffrtn);
+
+	# 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 @working_tree = ();
+	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 $null_mode) {
+			# Avoid duplicate working_tree entries
+			if ($working_tree_dups{$dst_path}++) {
+				next;
+			}
+			my ($use, $wt_sha1) =
+				use_wt_file($workdir, $dst_path, $rsha1);
+			if ($use) {
+				push @working_tree, $dst_path;
+				$wtindex .= "$rmode $wt_sha1\t$dst_path\0";
+			} else {
+				$rindex .= "$rmode $rsha1\t$dst_path\0";
+			}
+		}
+	}
+
+	# 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. Remove any trailing slash from $workdir
+	# before starting to avoid double slashes in symlink targets.
+	$workdir =~ s|/$||;
+	for my $file (@working_tree) {
+		my $dir = dirname($file);
+		unless (-d "$rdir/$dir") {
+			mkpath("$rdir/$dir") or
+			exit_cleanup($tmpdir, 1);
+		}
+		if ($symlinks) {
+			symlink("$workdir/$file", "$rdir/$file") or
+			exit_cleanup($tmpdir, 1);
+		} else {
+			copy("$workdir/$file", "$rdir/$file") or
+			exit_cleanup($tmpdir, 1);
+
+			my $mode = stat("$workdir/$file")->mode;
+			chmod($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, @working_tree);
+}
+
+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 $workdir = $repo->wc_path();
+	my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($workdir, $symlinks);
+
+	if (defined($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 (@worktree) {
+		next if $symlinks && -l "$b/$file";
+		next if ! -f "$b/$file";
+
+		if (!$indices_loaded) {
+			%wt_modified = changed_files(
+				$repo_path, "$tmpdir/wtindex", $workdir);
+			%tmp_modified = changed_files(
+				$repo_path, "$tmpdir/wtindex", $b);
+			$indices_loaded = 1;
+		}
+
+		if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
+			my $errmsg = "warning: Both files modified: ";
+			$errmsg .= "'$workdir/$file' and '$b/$file'.\n";
+			$errmsg .= "warning: Working tree file has been left.\n";
+			$errmsg .= "warning:\n";
+			warn $errmsg;
+			$error = 1;
+		} elsif (exists $tmp_modified{$file}) {
+			my $mode = stat("$b/$file")->mode;
+			copy("$b/$file", "$workdir/$file") or
+			exit_cleanup($tmpdir, 1);
+
+			chmod($mode, "$workdir/$file") or
+			exit_cleanup($tmpdir, 1);
+		}
+	}
+	if ($error) {
+		warn "warning: Temporary files exist in '$tmpdir'.\n";
+		warn "warning: You may want to cleanup or recover these.\n";
+		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();
diff --git a/git-legacy-difftool.perl b/git-legacy-difftool.perl
deleted file mode 100755
index a5790d03a0..0000000000
--- a/git-legacy-difftool.perl
+++ /dev/null
@@ -1,470 +0,0 @@
-#!/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;
-
-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 | ($status >> 8));
-}
-
-sub use_wt_file
-{
-	my ($workdir, $file, $sha1) = @_;
-	my $null_sha1 = '0' x 40;
-
-	if (-l "$workdir/$file" || ! -e _) {
-		return (0, $null_sha1);
-	}
-
-	my $wt_sha1 = Git::command_oneline('hash-object', "$workdir/$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 { $_ => 1 } @files;
-}
-
-sub setup_dir_diff
-{
-	my ($workdir, $symlinks) = @_;
-	my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
-	my $diffrtn = Git::command_oneline(@gitargs);
-	exit(0) unless defined($diffrtn);
-
-	# 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 @working_tree = ();
-	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 $null_mode) {
-			# Avoid duplicate working_tree entries
-			if ($working_tree_dups{$dst_path}++) {
-				next;
-			}
-			my ($use, $wt_sha1) =
-				use_wt_file($workdir, $dst_path, $rsha1);
-			if ($use) {
-				push @working_tree, $dst_path;
-				$wtindex .= "$rmode $wt_sha1\t$dst_path\0";
-			} else {
-				$rindex .= "$rmode $rsha1\t$dst_path\0";
-			}
-		}
-	}
-
-	# 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. Remove any trailing slash from $workdir
-	# before starting to avoid double slashes in symlink targets.
-	$workdir =~ s|/$||;
-	for my $file (@working_tree) {
-		my $dir = dirname($file);
-		unless (-d "$rdir/$dir") {
-			mkpath("$rdir/$dir") or
-			exit_cleanup($tmpdir, 1);
-		}
-		if ($symlinks) {
-			symlink("$workdir/$file", "$rdir/$file") or
-			exit_cleanup($tmpdir, 1);
-		} else {
-			copy("$workdir/$file", "$rdir/$file") or
-			exit_cleanup($tmpdir, 1);
-
-			my $mode = stat("$workdir/$file")->mode;
-			chmod($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, @working_tree);
-}
-
-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 $workdir = $repo->wc_path();
-	my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($workdir, $symlinks);
-
-	if (defined($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 (@worktree) {
-		next if $symlinks && -l "$b/$file";
-		next if ! -f "$b/$file";
-
-		if (!$indices_loaded) {
-			%wt_modified = changed_files(
-				$repo_path, "$tmpdir/wtindex", $workdir);
-			%tmp_modified = changed_files(
-				$repo_path, "$tmpdir/wtindex", $b);
-			$indices_loaded = 1;
-		}
-
-		if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
-			my $errmsg = "warning: Both files modified: ";
-			$errmsg .= "'$workdir/$file' and '$b/$file'.\n";
-			$errmsg .= "warning: Working tree file has been left.\n";
-			$errmsg .= "warning:\n";
-			warn $errmsg;
-			$error = 1;
-		} elsif (exists $tmp_modified{$file}) {
-			my $mode = stat("$b/$file")->mode;
-			copy("$b/$file", "$workdir/$file") or
-			exit_cleanup($tmpdir, 1);
-
-			chmod($mode, "$workdir/$file") or
-			exit_cleanup($tmpdir, 1);
-		}
-	}
-	if ($error) {
-		warn "warning: Temporary files exist in '$tmpdir'.\n";
-		warn "warning: You may want to cleanup or recover these.\n";
-		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 | ($rc >> 8));
-}
-
-main();
diff --git a/git.c b/git.c
index a8e6a15657..e68b6ebec6 100644
--- a/git.c
+++ b/git.c
@@ -424,12 +424,7 @@ static struct cmd_struct commands[] = {
 	{ "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 	{ "diff-index", cmd_diff_index, RUN_SETUP },
 	{ "diff-tree", cmd_diff_tree, RUN_SETUP },
-	/*
-	 * NEEDSWORK: Once the redirection to git-legacy-difftool.perl in
-	 * builtin/difftool.c has been removed, this entry should be changed to
-	 * RUN_SETUP | NEED_WORK_TREE
-	 */
-	{ "difftool", cmd_difftool },
+	{ "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
 	{ "fast-export", cmd_fast_export, RUN_SETUP },
 	{ "fetch", cmd_fetch, RUN_SETUP },
 	{ "fetch-pack", cmd_fetch_pack, RUN_SETUP },
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index b6a6c30f24..81a2de2b9d 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -23,10 +23,8 @@ prompt_given ()
 	test "$prompt" = "Launch 'test-tool' [Y/n]? branch"
 }
 
-# NEEDSWORK: lose all the PERL prereqs once legacy-difftool is retired.
-
 # Create a file on master and change it on branch
-test_expect_success PERL 'setup' '
+test_expect_success 'setup' '
 	echo master >file &&
 	git add file &&
 	git commit -m "added file" &&
@@ -38,7 +36,7 @@ test_expect_success PERL 'setup' '
 '
 
 # Configure a custom difftool.<tool>.cmd and use it
-test_expect_success PERL 'custom commands' '
+test_expect_success 'custom commands' '
 	difftool_test_setup &&
 	test_config difftool.test-tool.cmd "cat \"\$REMOTE\"" &&
 	echo master >expect &&
@@ -51,21 +49,21 @@ test_expect_success PERL 'custom commands' '
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'custom tool commands override built-ins' '
+test_expect_success 'custom tool commands override built-ins' '
 	test_config difftool.vimdiff.cmd "cat \"\$REMOTE\"" &&
 	echo master >expect &&
 	git difftool --tool vimdiff --no-prompt branch >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool ignores bad --tool values' '
+test_expect_success 'difftool ignores bad --tool values' '
 	: >expect &&
 	test_must_fail \
 		git difftool --no-prompt --tool=bad-tool branch >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool forwards arguments to diff' '
+test_expect_success 'difftool forwards arguments to diff' '
 	difftool_test_setup &&
 	>for-diff &&
 	git add for-diff &&
@@ -78,40 +76,40 @@ test_expect_success PERL 'difftool forwards arguments to diff' '
 	rm for-diff
 '
 
-test_expect_success PERL 'difftool ignores exit code' '
+test_expect_success 'difftool ignores exit code' '
 	test_config difftool.error.cmd false &&
 	git difftool -y -t error branch
 '
 
-test_expect_success PERL 'difftool forwards exit code with --trust-exit-code' '
+test_expect_success 'difftool forwards exit code with --trust-exit-code' '
 	test_config difftool.error.cmd false &&
 	test_must_fail git difftool -y --trust-exit-code -t error branch
 '
 
-test_expect_success PERL 'difftool forwards exit code with --trust-exit-code for built-ins' '
+test_expect_success 'difftool forwards exit code with --trust-exit-code for built-ins' '
 	test_config difftool.vimdiff.path false &&
 	test_must_fail git difftool -y --trust-exit-code -t vimdiff branch
 '
 
-test_expect_success PERL 'difftool honors difftool.trustExitCode = true' '
+test_expect_success 'difftool honors difftool.trustExitCode = true' '
 	test_config difftool.error.cmd false &&
 	test_config difftool.trustExitCode true &&
 	test_must_fail git difftool -y -t error branch
 '
 
-test_expect_success PERL 'difftool honors difftool.trustExitCode = false' '
+test_expect_success 'difftool honors difftool.trustExitCode = false' '
 	test_config difftool.error.cmd false &&
 	test_config difftool.trustExitCode false &&
 	git difftool -y -t error branch
 '
 
-test_expect_success PERL 'difftool ignores exit code with --no-trust-exit-code' '
+test_expect_success 'difftool ignores exit code with --no-trust-exit-code' '
 	test_config difftool.error.cmd false &&
 	test_config difftool.trustExitCode true &&
 	git difftool -y --no-trust-exit-code -t error branch
 '
 
-test_expect_success PERL 'difftool stops on error with --trust-exit-code' '
+test_expect_success 'difftool stops on error with --trust-exit-code' '
 	test_when_finished "rm -f for-diff .git/fail-right-file" &&
 	test_when_finished "git reset -- for-diff" &&
 	write_script .git/fail-right-file <<-\EOF &&
@@ -126,13 +124,13 @@ test_expect_success PERL 'difftool stops on error with --trust-exit-code' '
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool honors exit status if command not found' '
+test_expect_success 'difftool honors exit status if command not found' '
 	test_config difftool.nonexistent.cmd i-dont-exist &&
 	test_config difftool.trustExitCode false &&
 	test_must_fail git difftool -y -t nonexistent branch
 '
 
-test_expect_success PERL 'difftool honors --gui' '
+test_expect_success 'difftool honors --gui' '
 	difftool_test_setup &&
 	test_config merge.tool bogus-tool &&
 	test_config diff.tool bogus-tool &&
@@ -143,7 +141,7 @@ test_expect_success PERL 'difftool honors --gui' '
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool --gui last setting wins' '
+test_expect_success 'difftool --gui last setting wins' '
 	difftool_test_setup &&
 	: >expect &&
 	git difftool --no-prompt --gui --no-gui >actual &&
@@ -157,7 +155,7 @@ test_expect_success PERL 'difftool --gui last setting wins' '
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool --gui works without configured diff.guitool' '
+test_expect_success 'difftool --gui works without configured diff.guitool' '
 	difftool_test_setup &&
 	echo branch >expect &&
 	git difftool --no-prompt --gui branch >actual &&
@@ -165,7 +163,7 @@ test_expect_success PERL 'difftool --gui works without configured diff.guitool'
 '
 
 # Specify the diff tool using $GIT_DIFF_TOOL
-test_expect_success PERL 'GIT_DIFF_TOOL variable' '
+test_expect_success 'GIT_DIFF_TOOL variable' '
 	difftool_test_setup &&
 	git config --unset diff.tool &&
 	echo branch >expect &&
@@ -175,7 +173,7 @@ test_expect_success PERL 'GIT_DIFF_TOOL variable' '
 
 # Test the $GIT_*_TOOL variables and ensure
 # that $GIT_DIFF_TOOL always wins unless --tool is specified
-test_expect_success PERL 'GIT_DIFF_TOOL overrides' '
+test_expect_success 'GIT_DIFF_TOOL overrides' '
 	difftool_test_setup &&
 	test_config diff.tool bogus-tool &&
 	test_config merge.tool bogus-tool &&
@@ -193,7 +191,7 @@ test_expect_success PERL 'GIT_DIFF_TOOL overrides' '
 
 # Test that we don't have to pass --no-prompt to difftool
 # when $GIT_DIFFTOOL_NO_PROMPT is true
-test_expect_success PERL 'GIT_DIFFTOOL_NO_PROMPT variable' '
+test_expect_success 'GIT_DIFFTOOL_NO_PROMPT variable' '
 	difftool_test_setup &&
 	echo branch >expect &&
 	GIT_DIFFTOOL_NO_PROMPT=true git difftool branch >actual &&
@@ -202,7 +200,7 @@ test_expect_success PERL 'GIT_DIFFTOOL_NO_PROMPT variable' '
 
 # git-difftool supports the difftool.prompt variable.
 # Test that GIT_DIFFTOOL_PROMPT can override difftool.prompt = false
-test_expect_success PERL 'GIT_DIFFTOOL_PROMPT variable' '
+test_expect_success 'GIT_DIFFTOOL_PROMPT variable' '
 	difftool_test_setup &&
 	test_config difftool.prompt false &&
 	echo >input &&
@@ -212,7 +210,7 @@ test_expect_success PERL 'GIT_DIFFTOOL_PROMPT variable' '
 '
 
 # Test that we don't have to pass --no-prompt when difftool.prompt is false
-test_expect_success PERL 'difftool.prompt config variable is false' '
+test_expect_success 'difftool.prompt config variable is false' '
 	difftool_test_setup &&
 	test_config difftool.prompt false &&
 	echo branch >expect &&
@@ -221,7 +219,7 @@ test_expect_success PERL 'difftool.prompt config variable is false' '
 '
 
 # Test that we don't have to pass --no-prompt when mergetool.prompt is false
-test_expect_success PERL 'difftool merge.prompt = false' '
+test_expect_success 'difftool merge.prompt = false' '
 	difftool_test_setup &&
 	test_might_fail git config --unset difftool.prompt &&
 	test_config mergetool.prompt false &&
@@ -231,7 +229,7 @@ test_expect_success PERL 'difftool merge.prompt = false' '
 '
 
 # Test that the -y flag can override difftool.prompt = true
-test_expect_success PERL 'difftool.prompt can overridden with -y' '
+test_expect_success 'difftool.prompt can overridden with -y' '
 	difftool_test_setup &&
 	test_config difftool.prompt true &&
 	echo branch >expect &&
@@ -240,7 +238,7 @@ test_expect_success PERL 'difftool.prompt can overridden with -y' '
 '
 
 # Test that the --prompt flag can override difftool.prompt = false
-test_expect_success PERL 'difftool.prompt can overridden with --prompt' '
+test_expect_success 'difftool.prompt can overridden with --prompt' '
 	difftool_test_setup &&
 	test_config difftool.prompt false &&
 	echo >input &&
@@ -250,7 +248,7 @@ test_expect_success PERL 'difftool.prompt can overridden with --prompt' '
 '
 
 # Test that the last flag passed on the command-line wins
-test_expect_success PERL 'difftool last flag wins' '
+test_expect_success 'difftool last flag wins' '
 	difftool_test_setup &&
 	echo branch >expect &&
 	git difftool --prompt --no-prompt branch >actual &&
@@ -263,7 +261,7 @@ test_expect_success PERL 'difftool last flag wins' '
 
 # git-difftool falls back to git-mergetool config variables
 # so test that behavior here
-test_expect_success PERL 'difftool + mergetool config variables' '
+test_expect_success 'difftool + mergetool config variables' '
 	test_config merge.tool test-tool &&
 	test_config mergetool.test-tool.cmd "cat \$LOCAL" &&
 	echo branch >expect &&
@@ -277,49 +275,49 @@ test_expect_success PERL 'difftool + mergetool config variables' '
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool.<tool>.path' '
+test_expect_success 'difftool.<tool>.path' '
 	test_config difftool.tkdiff.path echo &&
 	git difftool --tool=tkdiff --no-prompt branch >output &&
 	lines=$(grep file output | wc -l) &&
 	test "$lines" -eq 1
 '
 
-test_expect_success PERL 'difftool --extcmd=cat' '
+test_expect_success 'difftool --extcmd=cat' '
 	echo branch >expect &&
 	echo master >>expect &&
 	git difftool --no-prompt --extcmd=cat branch >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool --extcmd cat' '
+test_expect_success 'difftool --extcmd cat' '
 	echo branch >expect &&
 	echo master >>expect &&
 	git difftool --no-prompt --extcmd=cat branch >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool -x cat' '
+test_expect_success 'difftool -x cat' '
 	echo branch >expect &&
 	echo master >>expect &&
 	git difftool --no-prompt -x cat branch >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool --extcmd echo arg1' '
+test_expect_success 'difftool --extcmd echo arg1' '
 	echo file >expect &&
 	git difftool --no-prompt \
 		--extcmd sh\ -c\ \"echo\ \$1\" branch >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool --extcmd cat arg1' '
+test_expect_success 'difftool --extcmd cat arg1' '
 	echo master >expect &&
 	git difftool --no-prompt \
 		--extcmd sh\ -c\ \"cat\ \$1\" branch >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success PERL 'difftool --extcmd cat arg2' '
+test_expect_success 'difftool --extcmd cat arg2' '
 	echo branch >expect &&
 	git difftool --no-prompt \
 		--extcmd sh\ -c\ \"cat\ \$2\" branch >actual &&
@@ -327,7 +325,7 @@ test_expect_success PERL 'difftool --extcmd cat arg2' '
 '
 
 # Create a second file on master and a different version on branch
-test_expect_success PERL 'setup with 2 files different' '
+test_expect_success 'setup with 2 files different' '
 	echo m2 >file2 &&
 	git add file2 &&
 	git commit -m "added file2" &&
@@ -339,7 +337,7 @@ test_expect_success PERL 'setup with 2 files different' '
 	git checkout master
 '
 
-test_expect_success PERL 'say no to the first file' '
+test_expect_success 'say no to the first file' '
 	(echo n && echo) >input &&
 	git difftool -x cat branch <input >output &&
 	grep m2 output &&
@@ -348,7 +346,7 @@ test_expect_success PERL 'say no to the first file' '
 	! grep branch output
 '
 
-test_expect_success PERL 'say no to the second file' '
+test_expect_success 'say no to the second file' '
 	(echo && echo n) >input &&
 	git difftool -x cat branch <input >output &&
 	grep master output &&
@@ -357,7 +355,7 @@ test_expect_success PERL 'say no to the second file' '
 	! grep br2 output
 '
 
-test_expect_success PERL 'ending prompt input with EOF' '
+test_expect_success 'ending prompt input with EOF' '
 	git difftool -x cat branch </dev/null >output &&
 	! grep master output &&
 	! grep branch output &&
@@ -365,12 +363,12 @@ test_expect_success PERL 'ending prompt input with EOF' '
 	! grep br2 output
 '
 
-test_expect_success PERL 'difftool --tool-help' '
+test_expect_success 'difftool --tool-help' '
 	git difftool --tool-help >output &&
 	grep tool output
 '
 
-test_expect_success PERL 'setup change in subdirectory' '
+test_expect_success 'setup change in subdirectory' '
 	git checkout master &&
 	mkdir sub &&
 	echo master >sub/sub &&
@@ -383,11 +381,11 @@ test_expect_success PERL 'setup change in subdirectory' '
 '
 
 run_dir_diff_test () {
-	test_expect_success PERL "$1 --no-symlinks" "
+	test_expect_success "$1 --no-symlinks" "
 		symlinks=--no-symlinks &&
 		$2
 	"
-	test_expect_success PERL,SYMLINKS "$1 --symlinks" "
+	test_expect_success SYMLINKS "$1 --symlinks" "
 		symlinks=--symlinks &&
 		$2
 	"
@@ -472,7 +470,7 @@ do
 done >actual
 EOF
 
-test_expect_success PERL,SYMLINKS 'difftool --dir-diff --symlink without unstaged changes' '
+test_expect_success SYMLINKS 'difftool --dir-diff --symlink without unstaged changes' '
 	cat >expect <<-EOF &&
 	file
 	$PWD/file
@@ -509,7 +507,7 @@ write_script modify-file <<\EOF
 echo "new content" >file
 EOF
 
-test_expect_success PERL 'difftool --no-symlinks does not overwrite working tree file ' '
+test_expect_success 'difftool --no-symlinks does not overwrite working tree file ' '
 	echo "orig content" >file &&
 	git difftool --dir-diff --no-symlinks --extcmd "$PWD/modify-file" branch &&
 	echo "new content" >expect &&
@@ -522,7 +520,7 @@ echo "tmp content" >"$2/file" &&
 echo "$2" >tmpdir
 EOF
 
-test_expect_success PERL 'difftool --no-symlinks detects conflict ' '
+test_expect_success 'difftool --no-symlinks detects conflict ' '
 	(
 		TMPDIR=$TRASH_DIRECTORY &&
 		export TMPDIR &&
@@ -535,7 +533,7 @@ test_expect_success PERL 'difftool --no-symlinks detects conflict ' '
 	)
 '
 
-test_expect_success PERL 'difftool properly honors gitlink and core.worktree' '
+test_expect_success 'difftool properly honors gitlink and core.worktree' '
 	git submodule add ./. submod/ule &&
 	test_config -C submod/ule diff.tool checktrees &&
 	test_config -C submod/ule difftool.checktrees.cmd '\''
@@ -549,7 +547,7 @@ test_expect_success PERL 'difftool properly honors gitlink and core.worktree' '
 	)
 '
 
-test_expect_success PERL,SYMLINKS 'difftool --dir-diff symlinked directories' '
+test_expect_success SYMLINKS 'difftool --dir-diff symlinked directories' '
 	git init dirlinks &&
 	(
 		cd dirlinks &&