From 35989c68ee5f577ae959f69281e456fd14460469 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Sun, 22 Jul 2012 20:57:07 -0700
Subject: [PATCH 01/13] difftool: Simplify print_tool_help()

Eliminate a global variable and File::Find usage by building upon
basename() and glob() instead.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 25 +++++--------------------
 1 file changed, 5 insertions(+), 20 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index c0798540a..ac0ed633b 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -13,17 +13,15 @@
 use 5.008;
 use strict;
 use warnings;
-use File::Basename qw(dirname);
+use File::Basename qw(basename dirname);
 use File::Copy;
 use File::Compare;
-use File::Find;
 use File::stat;
 use File::Path qw(mkpath);
 use File::Temp qw(tempdir);
 use Getopt::Long qw(:config pass_through);
 use Git;
 
-my @tools;
 my @working_tree;
 my $rc;
 my $repo = Git->repository();
@@ -65,26 +63,13 @@ sub find_worktree
 
 my $workdir = find_worktree();
 
-sub filter_tool_scripts
-{
-	if (-d $_) {
-		if ($_ ne ".") {
-			# Ignore files in subdirectories
-			$File::Find::prune = 1;
-		}
-	} else {
-		if ((-f $_) && ($_ ne "defaults")) {
-			push(@tools, $_);
-		}
-	}
-}
-
 sub print_tool_help
 {
 	my ($cmd, @found, @notfound);
 	my $gitpath = Git::exec_path();
 
-	find(\&filter_tool_scripts, "$gitpath/mergetools");
+	my @files = map { basename($_) } glob("$gitpath/mergetools/*");
+	my @tools = sort(grep { !m{^defaults$} } @files);
 
 	foreach my $tool (@tools) {
 		$cmd  = "TOOL_MODE=diff";
@@ -99,10 +84,10 @@ sub print_tool_help
 	}
 
 	print "'git difftool --tool=<tool>' may be set to one of the following:\n";
-	print "\t$_\n" for (sort(@found));
+	print "\t$_\n" for (@found);
 
 	print "\nThe following tools are valid, but not currently available:\n";
-	print "\t$_\n" for (sort(@notfound));
+	print "\t$_\n" for (@notfound);
 
 	print "\nNOTE: Some of the tools listed above only work in a windowed\n";
 	print "environment. If run in a terminal-only session, they will fail.\n";

From 75cd75830993e3b545f2b151d8eea2f3178f9ba4 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Sun, 22 Jul 2012 20:57:08 -0700
Subject: [PATCH 02/13] difftool: Eliminate global variables

Organize the script so that it has a single main() function which
calls out to dir_diff() and file_diff() functions. This eliminates
"dir-diff"-specific variables that do not need to be calculated when
performing a regular file-diff.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 128 +++++++++++++++++++++++++++-------------------
 1 file changed, 75 insertions(+), 53 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index ac0ed633b..41ba9323f 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -22,11 +22,6 @@
 use Getopt::Long qw(:config pass_through);
 use Git;
 
-my @working_tree;
-my $rc;
-my $repo = Git->repository();
-my $repo_path = $repo->repo_path();
-
 sub usage
 {
 	my $exitcode = shift;
@@ -43,6 +38,8 @@ sub usage
 
 sub find_worktree
 {
+	my ($repo) = @_;
+
 	# Git->repository->wc_path() does not honor changes to the working
 	# tree location made by $ENV{GIT_WORK_TREE} or the 'core.worktree'
 	# config variable.
@@ -61,8 +58,6 @@ sub find_worktree
 	return $worktree;
 }
 
-my $workdir = find_worktree();
-
 sub print_tool_help
 {
 	my ($cmd, @found, @notfound);
@@ -97,10 +92,13 @@ sub print_tool_help
 
 sub setup_dir_diff
 {
+	my ($repo, $workdir) = @_;
+
 	# Run the diff; exit immediately if no diff found
 	# 'Repository' and 'WorkingCopy' must be explicitly set to insure that
 	# if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
 	# by Git->repository->command*.
+	my $repo_path = $repo->repo_path();
 	my $diffrepo = Git->repository(Repository => $repo_path, WorkingCopy => $workdir);
 	my $diffrtn = $diffrepo->command_oneline('diff', '--raw', '--no-abbrev', '-z', @ARGV);
 	exit(0) if (length($diffrtn) == 0);
@@ -121,6 +119,7 @@ sub setup_dir_diff
 	my $rindex = '';
 	my %submodule;
 	my %symlink;
+	my @working_tree = ();
 	my @rawdiff = split('\0', $diffrtn);
 
 	my $i = 0;
@@ -188,7 +187,7 @@ sub setup_dir_diff
 	($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
 	print($inpipe $lindex);
 	$repo->command_close_pipe($inpipe, $ctx);
-	$rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
+	my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
 	exit($rc | ($rc >> 8)) if ($rc != 0);
 
 	$ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
@@ -238,7 +237,7 @@ sub setup_dir_diff
 		}
 	}
 
-	return ($ldir, $rdir);
+	return ($ldir, $rdir, @working_tree);
 }
 
 sub write_to_file
@@ -261,54 +260,70 @@ sub write_to_file
 	close($fh);
 }
 
-# parse command-line options. all unrecognized options and arguments
-# are passed through to the 'git diff' command.
-my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $prompt, $tool_help);
-GetOptions('g|gui!' => \$gui,
-	'd|dir-diff' => \$dirdiff,
-	'h' => \$help,
-	'prompt!' => \$prompt,
-	'y' => sub { $prompt = 0; },
-	't|tool:s' => \$difftool_cmd,
-	'tool-help' => \$tool_help,
-	'x|extcmd:s' => \$extcmd);
-
-if (defined($help)) {
-	usage(0);
-}
-if (defined($tool_help)) {
-	print_tool_help();
-}
-if (defined($difftool_cmd)) {
-	if (length($difftool_cmd) > 0) {
-		$ENV{GIT_DIFF_TOOL} = $difftool_cmd;
-	} else {
-		print "No <tool> given for --tool=<tool>\n";
-		usage(1);
+sub main
+{
+	# parse command-line options. all unrecognized options and arguments
+	# are passed through to the 'git diff' command.
+	my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $prompt, $tool_help);
+	GetOptions('g|gui!' => \$gui,
+		'd|dir-diff' => \$dirdiff,
+		'h' => \$help,
+		'prompt!' => \$prompt,
+		'y' => sub { $prompt = 0; },
+		't|tool:s' => \$difftool_cmd,
+		'tool-help' => \$tool_help,
+		'x|extcmd:s' => \$extcmd);
+
+	if (defined($help)) {
+		usage(0);
 	}
-}
-if (defined($extcmd)) {
-	if (length($extcmd) > 0) {
-		$ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
-	} else {
-		print "No <cmd> given for --extcmd=<cmd>\n";
-		usage(1);
+	if (defined($tool_help)) {
+		print_tool_help();
 	}
-}
-if ($gui) {
-	my $guitool = '';
-	$guitool = Git::config('diff.guitool');
-	if (length($guitool) > 0) {
-		$ENV{GIT_DIFF_TOOL} = $guitool;
+	if (defined($difftool_cmd)) {
+		if (length($difftool_cmd) > 0) {
+			$ENV{GIT_DIFF_TOOL} = $difftool_cmd;
+		} else {
+			print "No <tool> given for --tool=<tool>\n";
+			usage(1);
+		}
+	}
+	if (defined($extcmd)) {
+		if (length($extcmd) > 0) {
+			$ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
+		} else {
+			print "No <cmd> given for --extcmd=<cmd>\n";
+			usage(1);
+		}
+	}
+	if ($gui) {
+		my $guitool = '';
+		$guitool = Git::config('diff.guitool');
+		if (length($guitool) > 0) {
+			$ENV{GIT_DIFF_TOOL} = $guitool;
+		}
+	}
+
+	# In directory diff mode, 'git-difftool--helper' is called once
+	# to compare the a/b directories.  In file diff mode, 'git diff'
+	# will invoke a separate instance of 'git-difftool--helper' for
+	# each file that changed.
+	if (defined($dirdiff)) {
+		dir_diff($extcmd);
+	} else {
+		file_diff($prompt);
 	}
 }
 
-# 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($dirdiff)) {
-	my ($a, $b) = setup_dir_diff();
+sub dir_diff
+{
+	my ($extcmd) = @_;
+
+	my $rc;
+	my $repo = Git->repository();
+
+	my $workdir = find_worktree($repo);
+	my ($a, $b, @working_tree) = setup_dir_diff($repo, $workdir);
 	if (defined($extcmd)) {
 		$rc = system($extcmd, $a, $b);
 	} else {
@@ -327,7 +342,12 @@ sub write_to_file
 			chmod(stat("$b/$file")->mode, "$workdir/$file") or die $!;
 		}
 	}
-} else {
+}
+
+sub file_diff
+{
+	my ($prompt) = @_;
+
 	if (defined($prompt)) {
 		if ($prompt) {
 			$ENV{GIT_DIFFTOOL_PROMPT} = 'true';
@@ -347,3 +367,5 @@ sub write_to_file
 	my $rc = system('git', 'diff', @ARGV);
 	exit($rc | ($rc >> 8));
 }
+
+main();

From c9bdd505200120a8dab0f7417ad3fd7553e39e3f Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Sun, 22 Jul 2012 20:57:09 -0700
Subject: [PATCH 03/13] difftool: Move option values into a hash

Shorten the "my" declaration for all of the option-specific variables
by wrapping all of them in a hash.  This also gives us a place to
specify default values, should we need them.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 55 ++++++++++++++++++++++++++---------------------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 41ba9323f..0ce616840 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -264,41 +264,48 @@ sub main
 {
 	# parse command-line options. all unrecognized options and arguments
 	# are passed through to the 'git diff' command.
-	my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $prompt, $tool_help);
-	GetOptions('g|gui!' => \$gui,
-		'd|dir-diff' => \$dirdiff,
-		'h' => \$help,
-		'prompt!' => \$prompt,
-		'y' => sub { $prompt = 0; },
-		't|tool:s' => \$difftool_cmd,
-		'tool-help' => \$tool_help,
-		'x|extcmd:s' => \$extcmd);
-
-	if (defined($help)) {
+	my %opts = (
+		difftool_cmd => undef,
+		dirdiff => undef,
+		extcmd => undef,
+		gui => undef,
+		help => undef,
+		prompt => undef,
+		tool_help => undef,
+	);
+	GetOptions('g|gui!' => \$opts{gui},
+		'd|dir-diff' => \$opts{dirdiff},
+		'h' => \$opts{help},
+		'prompt!' => \$opts{prompt},
+		'y' => sub { $opts{prompt} = 0; },
+		't|tool:s' => \$opts{difftool_cmd},
+		'tool-help' => \$opts{tool_help},
+		'x|extcmd:s' => \$opts{extcmd});
+
+	if (defined($opts{help})) {
 		usage(0);
 	}
-	if (defined($tool_help)) {
+	if (defined($opts{tool_help})) {
 		print_tool_help();
 	}
-	if (defined($difftool_cmd)) {
-		if (length($difftool_cmd) > 0) {
-			$ENV{GIT_DIFF_TOOL} = $difftool_cmd;
+	if (defined($opts{difftool_cmd})) {
+		if (length($opts{difftool_cmd}) > 0) {
+			$ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
 		} else {
 			print "No <tool> given for --tool=<tool>\n";
 			usage(1);
 		}
 	}
-	if (defined($extcmd)) {
-		if (length($extcmd) > 0) {
-			$ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
+	if (defined($opts{extcmd})) {
+		if (length($opts{extcmd}) > 0) {
+			$ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
 		} else {
 			print "No <cmd> given for --extcmd=<cmd>\n";
 			usage(1);
 		}
 	}
-	if ($gui) {
-		my $guitool = '';
-		$guitool = Git::config('diff.guitool');
+	if ($opts{gui}) {
+		my $guitool = Git::config('diff.guitool');
 		if (length($guitool) > 0) {
 			$ENV{GIT_DIFF_TOOL} = $guitool;
 		}
@@ -308,10 +315,10 @@ sub main
 	# to compare the a/b directories.  In file diff mode, 'git diff'
 	# will invoke a separate instance of 'git-difftool--helper' for
 	# each file that changed.
-	if (defined($dirdiff)) {
-		dir_diff($extcmd);
+	if (defined($opts{dirdiff})) {
+		dir_diff($opts{extcmd});
 	} else {
-		file_diff($prompt);
+		file_diff($opts{prompt});
 	}
 }
 

From b965e8f44ad76a810c60406d01b45b87d6ac2701 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Sun, 22 Jul 2012 20:57:10 -0700
Subject: [PATCH 04/13] difftool: Call the temp directory "git-difftool"

The "diffall" name was left over from when this functionality was part of
the "git-diffall" script in contrib/.  Make the naming consistent.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 0ce616840..2ae344c7f 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -104,7 +104,7 @@ sub setup_dir_diff
 	exit(0) if (length($diffrtn) == 0);
 
 	# Setup temp directories
-	my $tmpdir = tempdir('git-diffall.XXXXX', CLEANUP => 1, TMPDIR => 1);
+	my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 1, TMPDIR => 1);
 	my $ldir = "$tmpdir/left";
 	my $rdir = "$tmpdir/right";
 	mkpath($ldir) or die $!;

From 1f2293457579a5bf22bb9c8324ded22b10705cc2 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Sun, 22 Jul 2012 23:05:30 -0700
Subject: [PATCH 05/13] difftool: Use symlinks when diffing against the
 worktree

Teach difftool's --dir-diff mode to use symlinks to represent
files from the working copy, and make it the default behavior
for the non-Windows platforms.

Using symlinks is simpler and safer since we do not need to
worry about copying files back into the worktree.
The old behavior is still available as --no-symlinks.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-difftool.txt |  8 ++++++++
 git-difftool.perl              | 33 +++++++++++++++++++++++----------
 2 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 31fc2e3ae..313d54e18 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -66,6 +66,14 @@ of the diff post-image.  `$MERGED` is the name of the file which is
 being compared. `$BASE` is provided for compatibility
 with custom merge tool commands and has the same value as `$MERGED`.
 
+--symlinks::
+--no-symlinks::
+	'git difftool''s default behavior is create symlinks to the
+	working tree when run in `--dir-diff` mode.
++
+	Specifying `--no-symlinks` instructs 'git difftool' to create
+	copies instead.  `--no-symlinks` is the default on Windows.
+
 --tool-help::
 	Print a list of diff tools that may be used with `--tool`.
 
diff --git a/git-difftool.perl b/git-difftool.perl
index 2ae344c7f..a5b371f72 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -92,7 +92,7 @@ sub print_tool_help
 
 sub setup_dir_diff
 {
-	my ($repo, $workdir) = @_;
+	my ($repo, $workdir, $symlinks) = @_;
 
 	# Run the diff; exit immediately if no diff found
 	# 'Repository' and 'WorkingCopy' must be explicitly set to insure that
@@ -209,8 +209,13 @@ sub setup_dir_diff
 		unless (-d "$rdir/$dir") {
 			mkpath("$rdir/$dir") or die $!;
 		}
-		copy("$workdir/$file", "$rdir/$file") or die $!;
-		chmod(stat("$workdir/$file")->mode, "$rdir/$file") or die $!;
+		if ($symlinks) {
+			symlink("$workdir/$file", "$rdir/$file") or die $!;
+		} else {
+			copy("$workdir/$file", "$rdir/$file") or die $!;
+			my $mode = stat("$workdir/$file")->mode;
+			chmod($mode, "$rdir/$file") or die $!;
+		}
 	}
 
 	# Changes to submodules require special treatment. This loop writes a
@@ -271,6 +276,7 @@ sub main
 		gui => undef,
 		help => undef,
 		prompt => undef,
+		symlinks => $^O ne 'MSWin32' && $^O ne 'msys',
 		tool_help => undef,
 	);
 	GetOptions('g|gui!' => \$opts{gui},
@@ -278,6 +284,8 @@ sub main
 		'h' => \$opts{help},
 		'prompt!' => \$opts{prompt},
 		'y' => sub { $opts{prompt} = 0; },
+		'symlinks' => \$opts{symlinks},
+		'no-symlinks' => sub { $opts{symlinks} = 0; },
 		't|tool:s' => \$opts{difftool_cmd},
 		'tool-help' => \$opts{tool_help},
 		'x|extcmd:s' => \$opts{extcmd});
@@ -316,7 +324,7 @@ sub main
 	# will invoke a separate instance of 'git-difftool--helper' for
 	# each file that changed.
 	if (defined($opts{dirdiff})) {
-		dir_diff($opts{extcmd});
+		dir_diff($opts{extcmd}, $opts{symlinks});
 	} else {
 		file_diff($opts{prompt});
 	}
@@ -324,13 +332,13 @@ sub main
 
 sub dir_diff
 {
-	my ($extcmd) = @_;
+	my ($extcmd, $symlinks) = @_;
 
 	my $rc;
 	my $repo = Git->repository();
 
 	my $workdir = find_worktree($repo);
-	my ($a, $b, @working_tree) = setup_dir_diff($repo, $workdir);
+	my ($a, $b, @worktree) = setup_dir_diff($repo, $workdir, $symlinks);
 	if (defined($extcmd)) {
 		$rc = system($extcmd, $a, $b);
 	} else {
@@ -342,13 +350,18 @@ sub dir_diff
 
 	# 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
-	for my $file (@working_tree) {
-		if (-e "$b/$file" && compare("$b/$file", "$workdir/$file")) {
+	# 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.
+	for my $file (@worktree) {
+		next if $symlinks && -l "$b/$file";
+		if (-f "$b/$file" && compare("$b/$file", "$workdir/$file")) {
 			copy("$b/$file", "$workdir/$file") or die $!;
-			chmod(stat("$b/$file")->mode, "$workdir/$file") or die $!;
+			my $mode = stat("$b/$file")->mode;
+			chmod($mode, "$workdir/$file") or die $!;
 		}
 	}
+	exit(0);
 }
 
 sub file_diff

From 7c7584b97096a168fe1236c84e5e12d7bee24476 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Tue, 24 Jul 2012 20:14:22 -0700
Subject: [PATCH 06/13] difftool: Handle finding mergetools/ in a path with
 spaces

Use the original File::Find implementation from bf73fc2 (difftool:
print list of valid tools with '--tool-help', 2012-03-29) so that we
properly handle mergetools/ being located in a path containing
spaces.

One small difference is that we avoid using a global variable by
passing a reference to the list of tools.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index a5b371f72..30574801b 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -13,9 +13,10 @@
 use 5.008;
 use strict;
 use warnings;
-use File::Basename qw(basename dirname);
+use File::Basename qw(dirname);
 use File::Copy;
 use File::Compare;
+use File::Find;
 use File::stat;
 use File::Path qw(mkpath);
 use File::Temp qw(tempdir);
@@ -58,13 +59,27 @@ sub find_worktree
 	return $worktree;
 }
 
+sub filter_tool_scripts
+{
+	my ($tools) = @_;
+	if (-d $_) {
+		if ($_ ne ".") {
+			# Ignore files in subdirectories
+			$File::Find::prune = 1;
+		}
+	} else {
+		if ((-f $_) && ($_ ne "defaults")) {
+			push(@$tools, $_);
+		}
+	}
+}
+
 sub print_tool_help
 {
-	my ($cmd, @found, @notfound);
+	my ($cmd, @found, @notfound, @tools);
 	my $gitpath = Git::exec_path();
 
-	my @files = map { basename($_) } glob("$gitpath/mergetools/*");
-	my @tools = sort(grep { !m{^defaults$} } @files);
+	find(sub { filter_tool_scripts(\@tools) }, "$gitpath/mergetools");
 
 	foreach my $tool (@tools) {
 		$cmd  = "TOOL_MODE=diff";
@@ -79,10 +94,10 @@ sub print_tool_help
 	}
 
 	print "'git difftool --tool=<tool>' may be set to one of the following:\n";
-	print "\t$_\n" for (@found);
+	print "\t$_\n" for (sort(@found));
 
 	print "\nThe following tools are valid, but not currently available:\n";
-	print "\t$_\n" for (@notfound);
+	print "\t$_\n" for (sort(@notfound));
 
 	print "\nNOTE: Some of the tools listed above only work in a windowed\n";
 	print "environment. If run in a terminal-only session, they will fail.\n";

From 283abb2c8abb3f40d8d0170ba45c2e45d40f8cdb Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Tue, 24 Jul 2012 20:14:23 -0700
Subject: [PATCH 07/13] difftool: Check all return codes from compare()

Handle the case where compare() is unable to read its inputs.
Emit a warning so that the user knows that something went wrong.

We may later want to restructure the code so that we can inhibit
tempdir cleanup when this condition is reached.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 30574801b..92f4907bb 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -370,7 +370,16 @@ sub dir_diff
 	# external tool did not replace the original link with a file.
 	for my $file (@worktree) {
 		next if $symlinks && -l "$b/$file";
-		if (-f "$b/$file" && compare("$b/$file", "$workdir/$file")) {
+		next if ! -f "$b/$file";
+
+		my $diff = compare("$b/$file", "$workdir/$file");
+		if ($diff == 0) {
+			next;
+		} elsif ($diff == -1) {
+			my $errmsg = "warning: Could not compare ";
+			$errmsg += "'$b/$file' with '$workdir/$file'\n";
+			warn $errmsg;
+		} elsif ($diff == 1) {
 			copy("$b/$file", "$workdir/$file") or die $!;
 			my $mode = stat("$b/$file")->mode;
 			chmod($mode, "$workdir/$file") or die $!;

From a4cd5be30cdd19c43908dc55d8dd39a0fe79075b Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Wed, 25 Jul 2012 23:07:57 -0700
Subject: [PATCH 08/13] difftool: Wrap long lines for readability

Keep everything within 80 columns.  Wrap the user-facing messages too.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 46 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 14 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 92f4907bb..1ec676aac 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -93,15 +93,22 @@ sub print_tool_help
 		}
 	}
 
-	print "'git difftool --tool=<tool>' may be set to one of the following:\n";
+	print << 'EOF';
+'git difftool --tool=<tool>' may be set to one of the following:
+EOF
 	print "\t$_\n" for (sort(@found));
 
-	print "\nThe following tools are valid, but not currently available:\n";
+	print << 'EOF';
+
+The following tools are valid, but not currently available:
+EOF
 	print "\t$_\n" for (sort(@notfound));
 
-	print "\nNOTE: Some of the tools listed above only work in a windowed\n";
-	print "environment. If run in a terminal-only session, they will fail.\n";
+	print << 'EOF';
 
+NOTE: Some of the tools listed above only work in a windowed
+environment. If run in a terminal-only session, they will fail.
+EOF
 	exit(0);
 }
 
@@ -114,8 +121,11 @@ sub setup_dir_diff
 	# if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
 	# by Git->repository->command*.
 	my $repo_path = $repo->repo_path();
-	my $diffrepo = Git->repository(Repository => $repo_path, WorkingCopy => $workdir);
-	my $diffrtn = $diffrepo->command_oneline('diff', '--raw', '--no-abbrev', '-z', @ARGV);
+	my %repo_args = (Repository => $repo_path, WorkingCopy => $workdir);
+	my $diffrepo = Git->repository(%repo_args);
+
+	my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
+	my $diffrtn = $diffrepo->command_oneline(@gitargs);
 	exit(0) if (length($diffrtn) == 0);
 
 	# Setup temp directories
@@ -140,11 +150,15 @@ sub setup_dir_diff
 	my $i = 0;
 	while ($i < $#rawdiff) {
 		if ($rawdiff[$i] =~ /^::/) {
-			print "Combined diff formats ('-c' and '--cc') are not supported in directory diff mode.\n";
+			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[$i], 1));
+		my ($lmode, $rmode, $lsha1, $rsha1, $status) =
+			split(' ', substr($rawdiff[$i], 1));
 		my $src_path = $rawdiff[$i + 1];
 		my $dst_path;
 
@@ -156,7 +170,7 @@ sub setup_dir_diff
 			$i += 2;
 		}
 
-		if (($lmode eq $submodule_mode) or ($rmode eq $submodule_mode)) {
+		if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
 			$submodule{$src_path}{left} = $lsha1;
 			if ($lsha1 ne $rsha1) {
 				$submodule{$dst_path}{right} = $rsha1;
@@ -167,14 +181,16 @@ sub setup_dir_diff
 		}
 
 		if ($lmode eq $symlink_mode) {
-			$symlink{$src_path}{left} = $diffrepo->command_oneline('show', "$lsha1");
+			$symlink{$src_path}{left} =
+				$diffrepo->command_oneline('show', "$lsha1");
 		}
 
 		if ($rmode eq $symlink_mode) {
-			$symlink{$dst_path}{right} = $diffrepo->command_oneline('show', "$rsha1");
+			$symlink{$dst_path}{right} =
+				$diffrepo->command_oneline('show', "$rsha1");
 		}
 
-		if (($lmode ne $null_mode) and ($status !~ /^C/)) {
+		if ($lmode ne $null_mode and $status !~ /^C/) {
 			$lindex .= "$lmode $lsha1\t$src_path\0";
 		}
 
@@ -199,14 +215,16 @@ sub setup_dir_diff
 	# Populate the left and right directories based on each index file
 	my ($inpipe, $ctx);
 	$ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
-	($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
+	($inpipe, $ctx) =
+		$repo->command_input_pipe(qw(update-index -z --index-info));
 	print($inpipe $lindex);
 	$repo->command_close_pipe($inpipe, $ctx);
 	my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
 	exit($rc | ($rc >> 8)) if ($rc != 0);
 
 	$ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
-	($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
+	($inpipe, $ctx) =
+		$repo->command_input_pipe(qw(update-index -z --index-info));
 	print($inpipe $rindex);
 	$repo->command_close_pipe($inpipe, $ctx);
 	$rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");

From ceb1497a74e75a0c9bd53716b787d33ad6e2397f Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Thu, 26 Jul 2012 12:36:19 -0700
Subject: [PATCH 09/13] difftool: Handle compare() returning -1

Keep the temporary directory around when compare()
cannot read its input files, which is indicated by -1.

Defer tempdir creation to allow an early exit in setup_dir_diff().
Wrap the rest of the entry points in an exit_cleanup() function
to handle removing temporary files and error reporting.

Print the temporary files' location so that the user can
recover them.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 99 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 68 insertions(+), 31 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 1ec676aac..6f8bb73cd 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -18,7 +18,7 @@
 use File::Compare;
 use File::Find;
 use File::stat;
-use File::Path qw(mkpath);
+use File::Path qw(mkpath rmtree);
 use File::Temp qw(tempdir);
 use Getopt::Long qw(:config pass_through);
 use Git;
@@ -112,6 +112,18 @@ sub print_tool_help
 	exit(0);
 }
 
+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 | ($status >> 8));
+}
+
 sub setup_dir_diff
 {
 	my ($repo, $workdir, $symlinks) = @_;
@@ -128,13 +140,6 @@ sub setup_dir_diff
 	my $diffrtn = $diffrepo->command_oneline(@gitargs);
 	exit(0) if (length($diffrtn) == 0);
 
-	# Setup temp directories
-	my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 1, TMPDIR => 1);
-	my $ldir = "$tmpdir/left";
-	my $rdir = "$tmpdir/right";
-	mkpath($ldir) or die $!;
-	mkpath($rdir) or die $!;
-
 	# Build index info for left and right sides of the diff
 	my $submodule_mode = '160000';
 	my $symlink_mode = '120000';
@@ -203,6 +208,13 @@ sub setup_dir_diff
 		}
 	}
 
+	# 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);
+
 	# If $GIT_DIR is not set prior to calling 'git update-index' and
 	# 'git checkout-index', then those commands will fail if difftool
 	# is called from a directory other than the repo root.
@@ -219,16 +231,18 @@ sub setup_dir_diff
 		$repo->command_input_pipe(qw(update-index -z --index-info));
 	print($inpipe $lindex);
 	$repo->command_close_pipe($inpipe, $ctx);
+
 	my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
-	exit($rc | ($rc >> 8)) if ($rc != 0);
+	exit_cleanup($tmpdir, $rc) if $rc != 0;
 
 	$ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
 	($inpipe, $ctx) =
 		$repo->command_input_pipe(qw(update-index -z --index-info));
 	print($inpipe $rindex);
 	$repo->command_close_pipe($inpipe, $ctx);
+
 	$rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
-	exit($rc | ($rc >> 8)) if ($rc != 0);
+	exit_cleanup($tmpdir, $rc) if $rc != 0;
 
 	# If $GIT_DIR was explicitly set just for the update/checkout
 	# commands, then it should be unset before continuing.
@@ -240,14 +254,19 @@ sub setup_dir_diff
 	for my $file (@working_tree) {
 		my $dir = dirname($file);
 		unless (-d "$rdir/$dir") {
-			mkpath("$rdir/$dir") or die $!;
+			mkpath("$rdir/$dir") or
+			exit_cleanup($tmpdir, 1);
 		}
 		if ($symlinks) {
-			symlink("$workdir/$file", "$rdir/$file") or die $!;
+			symlink("$workdir/$file", "$rdir/$file") or
+			exit_cleanup($tmpdir, 1);
 		} else {
-			copy("$workdir/$file", "$rdir/$file") or die $!;
+			copy("$workdir/$file", "$rdir/$file") or
+			exit_cleanup($tmpdir, 1);
+
 			my $mode = stat("$workdir/$file")->mode;
-			chmod($mode, "$rdir/$file") or die $!;
+			chmod($mode, "$rdir/$file") or
+			exit_cleanup($tmpdir, 1);
 		}
 	}
 
@@ -255,27 +274,35 @@ sub setup_dir_diff
 	# 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 $ok;
 		if (defined($submodule{$path}{left})) {
-			write_to_file("$ldir/$path", "Subproject commit $submodule{$path}{left}");
+			$ok = write_to_file("$ldir/$path",
+				"Subproject commit $submodule{$path}{left}");
 		}
 		if (defined($submodule{$path}{right})) {
-			write_to_file("$rdir/$path", "Subproject commit $submodule{$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 $ok;
 		if (defined($symlink{$path}{left})) {
-			write_to_file("$ldir/$path", $symlink{$path}{left});
+			$ok = write_to_file("$ldir/$path",
+					$symlink{$path}{left});
 		}
 		if (defined($symlink{$path}{right})) {
-			write_to_file("$rdir/$path", $symlink{$path}{right});
+			$ok = write_to_file("$rdir/$path",
+					$symlink{$path}{right});
 		}
+		exit_cleanup($tmpdir, 1) if not $ok;
 	}
 
-	return ($ldir, $rdir, @working_tree);
+	return ($ldir, $rdir, $tmpdir, @working_tree);
 }
 
 sub write_to_file
@@ -286,16 +313,18 @@ sub write_to_file
 	# Make sure the path to the file exists
 	my $dir = dirname($path);
 	unless (-d "$dir") {
-		mkpath("$dir") or die $!;
+		mkpath("$dir") or return 0;
 	}
 
 	# If the file already exists in that location, delete it.  This
 	# is required in the case of symbolic links.
-	unlink("$path");
+	unlink($path);
 
-	open(my $fh, '>', "$path") or die $!;
+	open(my $fh, '>', $path) or return 0;
 	print($fh $value);
 	close($fh);
+
+	return 1;
 }
 
 sub main
@@ -366,21 +395,19 @@ sub main
 sub dir_diff
 {
 	my ($extcmd, $symlinks) = @_;
-
 	my $rc;
+	my $error = 0;
 	my $repo = Git->repository();
-
 	my $workdir = find_worktree($repo);
-	my ($a, $b, @worktree) = setup_dir_diff($repo, $workdir, $symlinks);
+	my ($a, $b, $tmpdir, @worktree) =
+		setup_dir_diff($repo, $workdir, $symlinks);
+
 	if (defined($extcmd)) {
 		$rc = system($extcmd, $a, $b);
 	} else {
 		$ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
 		$rc = system('git', 'difftool--helper', $a, $b);
 	}
-
-	exit($rc | ($rc >> 8)) if ($rc != 0);
-
 	# 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.
@@ -397,13 +424,23 @@ sub dir_diff
 			my $errmsg = "warning: Could not compare ";
 			$errmsg += "'$b/$file' with '$workdir/$file'\n";
 			warn $errmsg;
+			$error = 1;
 		} elsif ($diff == 1) {
-			copy("$b/$file", "$workdir/$file") or die $!;
 			my $mode = stat("$b/$file")->mode;
-			chmod($mode, "$workdir/$file") or die $!;
+			copy("$b/$file", "$workdir/$file") or
+			exit_cleanup($tmpdir, 1);
+
+			chmod($mode, "$workdir/$file") or
+			exit_cleanup($tmpdir, 1);
 		}
 	}
-	exit(0);
+	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

From 190f5475f2a7edb777b65367d8796177aa13c830 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Tue, 24 Jul 2012 20:14:24 -0700
Subject: [PATCH 10/13] difftool: Disable --symlinks on cygwin

Symlinks are not ubiquitous on Windows so make --no-symlinks the default.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 6f8bb73cd..17d4de661 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -338,7 +338,8 @@ sub main
 		gui => undef,
 		help => undef,
 		prompt => undef,
-		symlinks => $^O ne 'MSWin32' && $^O ne 'msys',
+		symlinks => $^O ne 'cygwin' &&
+				$^O ne 'MSWin32' && $^O ne 'msys',
 		tool_help => undef,
 	);
 	GetOptions('g|gui!' => \$opts{gui},

From 7a30747fbacd9a2059e861cba80ebd67685ffe80 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Fri, 10 Aug 2012 00:39:22 -0700
Subject: [PATCH 11/13] mergetool,difftool: Document --tool-help consistently

Add an entry for --tool-help to the mergetool documentation.

Move --tool-help in the difftool documentation so that it is
listed immediately after --tool so that it is easier to find.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-difftool.txt  | 6 +++---
 Documentation/git-mergetool.txt | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 313d54e18..73ca7025a 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -66,6 +66,9 @@ of the diff post-image.  `$MERGED` is the name of the file which is
 being compared. `$BASE` is provided for compatibility
 with custom merge tool commands and has the same value as `$MERGED`.
 
+--tool-help::
+	Print a list of diff tools that may be used with `--tool`.
+
 --symlinks::
 --no-symlinks::
 	'git difftool''s default behavior is create symlinks to the
@@ -74,9 +77,6 @@ with custom merge tool commands and has the same value as `$MERGED`.
 	Specifying `--no-symlinks` instructs 'git difftool' to create
 	copies instead.  `--no-symlinks` is the default on Windows.
 
---tool-help::
-	Print a list of diff tools that may be used with `--tool`.
-
 -x <command>::
 --extcmd=<command>::
 	Specify a custom command for viewing diffs.
diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 2a49de7cf..77dfdab2d 100644
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -64,6 +64,9 @@ variable `mergetool.<tool>.trustExitCode` can be set to `true`.
 Otherwise, 'git mergetool' will prompt the user to indicate the
 success of the resolution after the custom tool has exited.
 
+--tool-help::
+	Print a list of merge tools that may be used with `--tool`.
+
 -y::
 --no-prompt::
 	Don't prompt before each invocation of the merge resolution

From 755e8b3f35e3991a735a6be740eda4567d45a741 Mon Sep 17 00:00:00 2001
From: Sebastian Schuberth <sschuberth@gmail.com>
Date: Fri, 10 Aug 2012 10:21:06 +0200
Subject: [PATCH 12/13] Add Code Compare v2.80.4 as a merge / diff tool for
 Windows

Code Compare is a commercial file comparison tool for Windows, see

    http://www.devart.com/codecompare/

Version 2.80.4 added support for command line arguments preceded by a
dash instead of a slash. This is required for Git for Windows because
slashes in command line arguments get mangled with according to these
rules:

    http://www.mingw.org/wiki/Posix_path_conversion

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 contrib/completion/git-completion.bash |  2 +-
 git-mergetool--lib.sh                  |  2 +-
 mergetools/codecompare                 | 25 +++++++++++++++++++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)
 create mode 100644 mergetools/codecompare

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 2e1b5e14b..820ac738c 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1319,7 +1319,7 @@ _git_diff ()
 }
 
 __git_mergetools_common="diffuse ecmerge emerge kdiff3 meld opendiff
-			tkdiff vimdiff gvimdiff xxdiff araxis p4merge bc3
+			tkdiff vimdiff gvimdiff xxdiff araxis p4merge bc3 codecompare
 "
 
 _git_difftool ()
diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index ed630b208..0bbfcb144 100644
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -126,7 +126,7 @@ guess_merge_tool () {
 		else
 			tools="opendiff kdiff3 tkdiff xxdiff meld $tools"
 		fi
-		tools="$tools gvimdiff diffuse ecmerge p4merge araxis bc3"
+		tools="$tools gvimdiff diffuse ecmerge p4merge araxis bc3 codecompare"
 	fi
 	case "${VISUAL:-$EDITOR}" in
 	*vim*)
diff --git a/mergetools/codecompare b/mergetools/codecompare
new file mode 100644
index 000000000..3f0486bc8
--- /dev/null
+++ b/mergetools/codecompare
@@ -0,0 +1,25 @@
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	if $base_present
+	then
+		"$merge_tool_path" -MF="$LOCAL" -TF="$REMOTE" -BF="$BASE" \
+			-RF="$MERGED"
+	else
+		"$merge_tool_path" -MF="$LOCAL" -TF="$REMOTE" \
+			-RF="$MERGED"
+	fi
+	check_unchanged
+}
+
+translate_merge_tool_path() {
+	if merge_mode
+	then
+		echo CodeMerge
+	else
+		echo CodeCompare
+	fi
+}

From ed36e5bd41f7192e42e9b4c573875a343a9daf48 Mon Sep 17 00:00:00 2001
From: Ross Lagerwall <rosslagerwall@gmail.com>
Date: Tue, 21 Aug 2012 12:21:40 +0200
Subject: [PATCH 13/13] difftool: silence warning

Silence a warning given when running git difftool --dir-diff and
there are no changes.

This is because command_oneline returns undef when the command has no
output, not ''.

Signed-off-by: Ross Lagerwall <rosslagerwall@gmail.com>
Acked-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-difftool.perl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 17d4de661..edd0493a0 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -138,7 +138,7 @@ sub setup_dir_diff
 
 	my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
 	my $diffrtn = $diffrepo->command_oneline(@gitargs);
-	exit(0) if (length($diffrtn) == 0);
+	exit(0) unless defined($diffrtn);
 
 	# Build index info for left and right sides of the diff
 	my $submodule_mode = '160000';