From ecc4ee9cac60600f38542cebd940b4bd8b6497c8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:40 +0200
Subject: [PATCH 01/13] send-email tests: support
 GIT_TEST_PERL_FATAL_WARNINGS=true
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add support for the "GIT_TEST_PERL_FATAL_WARNINGS=true" test mode to
"send-email". This was added to e.g. git-svn in 5338ed2b26 (perl:
check for perl warnings while running tests, 2020-10-21), but not
"send-email". Let's rectify that.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index 25be2ebd2af..1630e87cd4d 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -18,7 +18,7 @@
 
 use 5.008;
 use strict;
-use warnings;
+use warnings $ENV{GIT_PERL_FATAL_WARNINGS} ? qw(FATAL all) : ();
 use POSIX qw/strftime/;
 use Term::ReadLine;
 use Getopt::Long;

From 879be4319f70a2d6c65c3444a269bff671d182cd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:41 +0200
Subject: [PATCH 02/13] send-email tests: test for boolean variables without a
 value
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The Git.pm code does its own Perl-ifying of boolean variables, let's
ensure that empty values = true for boolean variables, as in the C
code.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t9001-send-email.sh | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 3b7540050ca..612de095fd7 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -1368,6 +1368,16 @@ test_expect_success $PREREQ 'sendemail.identity: bool variable fallback' '
 	! grep "X-Mailer" stdout
 '
 
+test_expect_success $PREREQ 'sendemail.identity: bool variable without a value' '
+	git -c sendemail.xmailer \
+		send-email \
+		--dry-run \
+		--from="nobody@example.com" \
+		$patches >stdout &&
+	grep "To: default@example.com" stdout &&
+	grep "X-Mailer" stdout
+'
+
 test_expect_success $PREREQ '--no-to overrides sendemail.to' '
 	git send-email \
 		--dry-run \
@@ -2092,6 +2102,18 @@ test_expect_success $PREREQ '--[no-]xmailer with sendemail.xmailer=true' '
 	do_xmailer_test 1 "--xmailer"
 '
 
+test_expect_success $PREREQ '--[no-]xmailer with sendemail.xmailer' '
+	test_when_finished "test_unconfig sendemail.xmailer" &&
+	cat >>.git/config <<-\EOF &&
+	[sendemail]
+		xmailer
+	EOF
+	test_config sendemail.xmailer true &&
+	do_xmailer_test 1 "" &&
+	do_xmailer_test 0 "--no-xmailer" &&
+	do_xmailer_test 1 "--xmailer"
+'
+
 test_expect_success $PREREQ '--[no-]xmailer with sendemail.xmailer=false' '
 	test_config sendemail.xmailer false &&
 	do_xmailer_test 0 "" &&
@@ -2099,6 +2121,13 @@ test_expect_success $PREREQ '--[no-]xmailer with sendemail.xmailer=false' '
 	do_xmailer_test 1 "--xmailer"
 '
 
+test_expect_success $PREREQ '--[no-]xmailer with sendemail.xmailer=' '
+	test_config sendemail.xmailer "" &&
+	do_xmailer_test 0 "" &&
+	do_xmailer_test 0 "--no-xmailer" &&
+	do_xmailer_test 1 "--xmailer"
+'
+
 test_expect_success $PREREQ 'setup expected-list' '
 	git send-email \
 	--dry-run \

From 671818ab0b8206481d38054477059fee46db0ba3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:42 +0200
Subject: [PATCH 03/13] send-email: remove non-working support for
 "sendemail.smtpssl"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Remove the already dead code to support "sendemail.smtpssl" by finally
removing the dead code supporting the configuration option.

In f6bebd121ac (git-send-email: add support for TLS via
Net::SMTP::SSL, 2008-06-25) the --smtp-ssl command-line option was
documented as deprecated, later in 65180c66186 (List send-email config
options in config.txt., 2009-07-22) the "sendemail.smtpssl"
configuration option was also documented as such.

Then in in 3ff15040e22 (send-email: fix regression in
sendemail.identity parsing, 2019-05-17) I unintentionally removed
support for it by introducing a bug in read_config().

As can be seen from the diff context we've already returned unless
$enc i defined, so it's not possible for us to reach the "elsif"
branch here. This code was therefore already dead since Git v2.23.0.

So let's just remove it. We were already 11 years into a stated
deprecation period of this variable when 3ff15040e22 landed, now it's
around 13. Since it hasn't worked anyway for around 2 years it looks
like we can safely remove it.

The --smtp-ssl option is still deprecated, if someone cares they can
follow-up and remove that too, but unlike the config option that one
could still be in use in the wild. I'm just removing this code that's
provably unused already.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/config/sendemail.txt | 3 ---
 git-send-email.perl                | 6 +-----
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/Documentation/config/sendemail.txt b/Documentation/config/sendemail.txt
index cbc5af42fdf..50baa5d6bfb 100644
--- a/Documentation/config/sendemail.txt
+++ b/Documentation/config/sendemail.txt
@@ -8,9 +8,6 @@ sendemail.smtpEncryption::
 	See linkgit:git-send-email[1] for description.  Note that this
 	setting is not subject to the 'identity' mechanism.
 
-sendemail.smtpssl (deprecated)::
-	Deprecated alias for 'sendemail.smtpEncryption = ssl'.
-
 sendemail.smtpsslcertpath::
 	Path to ca-certificates (either a directory or a single file).
 	Set it to an empty string to disable certificate verification.
diff --git a/git-send-email.perl b/git-send-email.perl
index 1630e87cd4d..9a1a4898e36 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -393,11 +393,7 @@ sub read_config {
 		my $enc = Git::config(@repo, $setting);
 		return unless defined $enc;
 		return if $configured->{$setting}++;
-		if (defined $enc) {
-			$smtp_encryption = $enc;
-		} elsif (Git::config_bool(@repo, "$prefix.smtpssl")) {
-			$smtp_encryption = 'ssl';
-		}
+		$smtp_encryption = $enc;
 	}
 }
 

From 119974e9e7f3569400aa1950529f69431534a617 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:43 +0200
Subject: [PATCH 04/13] send-email: refactor sendemail.smtpencryption config
 parsing
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

With the removal of the support for sendemail.smtpssl in the preceding
commit the parsing of sendemail.smtpencryption is no longer special,
and can by moved to %config_settings.

This gets us rid of an unconditional call to Git::config(), which as
we'll see in subsequent commits matters for startup performance.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index 9a1a4898e36..e2fe112aa50 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -287,6 +287,7 @@ sub do_edit {
 );
 
 my %config_settings = (
+    "smtpencryption" => \$smtp_encryption,
     "smtpserver" => \$smtp_server,
     "smtpserverport" => \$smtp_server_port,
     "smtpserveroption" => \@smtp_server_options,
@@ -387,14 +388,6 @@ sub read_config {
 			$$target = $v;
 		}
 	}
-
-	if (!defined $smtp_encryption) {
-		my $setting = "$prefix.smtpencryption";
-		my $enc = Git::config(@repo, $setting);
-		return unless defined $enc;
-		return if $configured->{$setting}++;
-		$smtp_encryption = $enc;
-	}
 }
 
 # sendemail.identity yields to --identity. We must parse this

From 2b110e9ba255120a2d78a5d2cccc842519e341f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:44 +0200
Subject: [PATCH 05/13] send-email: copy "config_regxp" into
 git-send-email.perl
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The config_regexp() function was added in dd84e528a3 (git-send-email:
die if sendmail.* config is set, 2020-07-23) for use in
git-send-email, and it's the only in-tree user of it.

However, the consensus is that Git.pm is a public interface, so even
though it's a recently added function we can't change it. So let's
copy over a minimal version of it to git-send-email.perl itself. In a
subsequent commit it'll be changed further for our own use.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index e2fe112aa50..73e3d3fd26e 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -390,6 +390,24 @@ sub read_config {
 	}
 }
 
+sub config_regexp {
+	my ($regex) = @_;
+	my @ret;
+	eval {
+		@ret = Git::command(
+			'config',
+			'--name-only',
+			'--get-regexp',
+			$regex,
+		);
+		1;
+	} or do {
+		# If we have no keys we're OK, otherwise re-throw
+		die $@ if $@->value != 1;
+	};
+	return @ret;
+}
+
 # sendemail.identity yields to --identity. We must parse this
 # special-case first before the rest of the config is read.
 $identity = Git::config(@repo, "sendemail.identity");
@@ -488,7 +506,7 @@ sub read_config {
     usage();
 }
 
-if ($forbid_sendmail_variables && (scalar Git::config_regexp("^sendmail[.]")) != 0) {
+if ($forbid_sendmail_variables && (scalar config_regexp("^sendmail[.]")) != 0) {
 	die __("fatal: found configuration options for 'sendmail'\n" .
 		"git-send-email is configured with the sendemail.* options - note the 'e'.\n" .
 		"Set sendemail.forbidSendmailVariables to false to disable this check.\n");

From 9264d29bf6da9e1789d71807dd72bbd4fb447887 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:45 +0200
Subject: [PATCH 06/13] send-email: lazily load config for a big speedup
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Reduce the time it takes git-send-email to get to even the most
trivial of tasks (such as serving up its "-h" output) by first listing
config keys that exist, and only then only call e.g. "git config
--bool" on them if they do.

Over a lot of runs this speeds the time to "-h" up for me from ~250ms
to ~150ms, and the runtime of t9001-send-email.sh goes from ~25s to
~20s.

This introduces a race condition where we'll do the "wrong" thing if a
config key were to be inserted between us discovering the list and
calling read_config(), i.e. we won't know about the racily added
key. In theory this is a change in behavior, in practice it doesn't
matter.

The config_regexp() function being changed here was added in
dd84e528a34 (git-send-email: die if sendmail.* config is set,
2020-07-23) for use by git-send-email. So we can change its odd return
value in the case where no values are found by "git config". The
difference in the *.pm code would matter if it was invoked in scalar
context, but now it no longer is.

Arguably this caching belongs in Git.pm itself, but in lieu of
modifying it for all its callers let's only do this for "git
send-email". The other big potential win would be "git svn", but
unlike "git send-email" it doesn't check tens of config variables one
at a time at startup (in my brief testing it doesn't check any).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index 73e3d3fd26e..de62cbf2506 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -347,11 +347,13 @@ sub signal_handler {
 
 # Read our sendemail.* config
 sub read_config {
-	my ($configured, $prefix) = @_;
+	my ($known_keys, $configured, $prefix) = @_;
 
 	foreach my $setting (keys %config_bool_settings) {
 		my $target = $config_bool_settings{$setting};
-		my $v = Git::config_bool(@repo, "$prefix.$setting");
+		my $key = "$prefix.$setting";
+		next unless exists $known_keys->{$key};
+		my $v = Git::config_bool(@repo, $key);
 		next unless defined $v;
 		next if $configured->{$setting}++;
 		$$target = $v;
@@ -359,8 +361,10 @@ sub read_config {
 
 	foreach my $setting (keys %config_path_settings) {
 		my $target = $config_path_settings{$setting};
+		my $key = "$prefix.$setting";
+		next unless exists $known_keys->{$key};
 		if (ref($target) eq "ARRAY") {
-			my @values = Git::config_path(@repo, "$prefix.$setting");
+			my @values = Git::config_path(@repo, $key);
 			next unless @values;
 			next if $configured->{$setting}++;
 			@$target = @values;
@@ -375,14 +379,16 @@ sub read_config {
 
 	foreach my $setting (keys %config_settings) {
 		my $target = $config_settings{$setting};
+		my $key = "$prefix.$setting";
+		next unless exists $known_keys->{$key};
 		if (ref($target) eq "ARRAY") {
-			my @values = Git::config(@repo, "$prefix.$setting");
+			my @values = Git::config(@repo, $key);
 			next unless @values;
 			next if $configured->{$setting}++;
 			@$target = @values;
 		}
 		else {
-			my $v = Git::config(@repo, "$prefix.$setting");
+			my $v = Git::config(@repo, $key);
 			next unless defined $v;
 			next if $configured->{$setting}++;
 			$$target = $v;
@@ -408,9 +414,20 @@ sub config_regexp {
 	return @ret;
 }
 
+# Save ourselves a lot of work of shelling out to 'git config' (it
+# parses 'bool' etc.) by only doing so for config keys that exist.
+my %known_config_keys;
+{
+	my @known_config_keys = config_regexp("^sende?mail[.]");
+	@known_config_keys{@known_config_keys} = ();
+}
+
 # sendemail.identity yields to --identity. We must parse this
 # special-case first before the rest of the config is read.
-$identity = Git::config(@repo, "sendemail.identity");
+{
+	my $key = "sendemail.identity";
+	$identity = Git::config(@repo, $key) if exists $known_config_keys{$key};
+}
 my $rc = GetOptions(
 	"identity=s" => \$identity,
 	"no-identity" => \$no_identity,
@@ -421,8 +438,8 @@ sub config_regexp {
 # Now we know enough to read the config
 {
     my %configured;
-    read_config(\%configured, "sendemail.$identity") if defined $identity;
-    read_config(\%configured, "sendemail");
+    read_config(\%known_config_keys, \%configured, "sendemail.$identity") if defined $identity;
+    read_config(\%known_config_keys, \%configured, "sendemail");
 }
 
 # Begin by accumulating all the variables (defined above), that we will end up
@@ -506,7 +523,7 @@ sub config_regexp {
     usage();
 }
 
-if ($forbid_sendmail_variables && (scalar config_regexp("^sendmail[.]")) != 0) {
+if ($forbid_sendmail_variables && grep { /^sendmail/s } keys %known_config_keys) {
 	die __("fatal: found configuration options for 'sendmail'\n" .
 		"git-send-email is configured with the sendemail.* options - note the 'e'.\n" .
 		"Set sendemail.forbidSendmailVariables to false to disable this check.\n");

From fef381e6dcbc328c4ccabaf4e8d4cdf19d1aba00 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:46 +0200
Subject: [PATCH 07/13] send-email: lazily shell out to "git var"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Optimize git-send-email by only shelling out to "git var" if we need
to. This is easily done by re-inventing our own small version of
perl's Memoize module.

I suppose I could just use Memoize itself, but in a subsequent patch
I'll be micro-optimizing send-email's use of dependencies. Using
Memoize is a measly extra 5-10 milliseconds, but as we'll see that'll
end up mattering for us in the end.

This brings the runtime of a plain "send-email" from around ~160-170ms
to ~140m-150ms. The runtime of the tests is around the same, or around
~20s.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index de62cbf2506..38408ec75a8 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -588,8 +588,18 @@ sub config_regexp {
 }
 
 my ($repoauthor, $repocommitter);
-($repoauthor) = Git::ident_person(@repo, 'author');
-($repocommitter) = Git::ident_person(@repo, 'committer');
+{
+	my %cache;
+	my ($author, $committer);
+	my $common = sub {
+		my ($what) = @_;
+		return $cache{$what} if exists $cache{$what};
+		($cache{$what}) = Git::ident_person(@repo, $what);
+		return $cache{$what};
+	};
+	$repoauthor = sub { $common->('author') };
+	$repocommitter = sub { $common->('committer') };
+}
 
 sub parse_address_line {
 	return map { $_->format } Mail::Address->parse($_[0]);
@@ -777,7 +787,7 @@ sub get_patch_subject {
 		or die sprintf(__("Failed to open for writing %s: %s"), $compose_filename, $!);
 
 
-	my $tpl_sender = $sender || $repoauthor || $repocommitter || '';
+	my $tpl_sender = $sender || $repoauthor->() || $repocommitter->() || '';
 	my $tpl_subject = $initial_subject || '';
 	my $tpl_in_reply_to = $initial_in_reply_to || '';
 	my $tpl_reply_to = $reply_to || '';
@@ -983,7 +993,7 @@ sub file_declares_8bit_cte {
 	$sender =~ s/^\s+|\s+$//g;
 	($sender) = expand_aliases($sender);
 } else {
-	$sender = $repoauthor || $repocommitter || '';
+	$sender = $repoauthor->() || $repocommitter->() || '';
 }
 
 # $sender could be an already sanitized address
@@ -1132,7 +1142,7 @@ sub make_message_id {
 	$uniq = "$message_id_stamp-$message_id_serial";
 
 	my $du_part;
-	for ($sender, $repocommitter, $repoauthor) {
+	for ($sender, $repocommitter->(), $repoauthor->()) {
 		$du_part = extract_valid_address(sanitize_address($_));
 		last if (defined $du_part and $du_part ne '');
 	}

From 4adbf387bfd4b03b838282757e0bdf67e8f9fc8d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:47 +0200
Subject: [PATCH 08/13] send-email: use function syntax instead of barewords
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Change calls like "__ 'foo'" to "__('foo')" so the Perl compiler
doesn't have to guess that "__" is a function. This makes the code
more readable.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index 38408ec75a8..44dc3f6eb10 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -706,7 +706,7 @@ sub is_format_patch_arg {
 		if (defined($format_patch)) {
 			return $format_patch;
 		}
-		die sprintf(__ <<EOF, $f, $f);
+		die sprintf(__(<<EOF), $f, $f);
 File '%s' exists but it could also be the range of commits
 to produce patches for.  Please disambiguate by...
 
@@ -792,7 +792,7 @@ sub get_patch_subject {
 	my $tpl_in_reply_to = $initial_in_reply_to || '';
 	my $tpl_reply_to = $reply_to || '';
 
-	print $c <<EOT1, Git::prefix_lines("GIT: ", __ <<EOT2), <<EOT3;
+	print $c <<EOT1, Git::prefix_lines("GIT: ", __(<<EOT2)), <<EOT3;
 From $tpl_sender # This line is ignored.
 EOT1
 Lines beginning in "GIT:" will be removed.

From 447ed29c0d414547914c23e92f8bb13fcf748f9b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:48 +0200
Subject: [PATCH 09/13] send-email: get rid of indirect object syntax
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Change indirect object syntax such as "new X ARGS" to
"X->new(ARGS)". This allows perl to see what "new" is at compile-time
without having loaded Term::ReadLine. This doesn't matter now, but
will in a subsequent commit when we start lazily loading it.

Let's do the same for the adjacent "FakeTerm" package for consistency,
even though we're not going to conditionally load it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index 44dc3f6eb10..cc1027d8774 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -194,11 +194,11 @@ sub format_2822_time {
 my @repo = $repo ? ($repo) : ();
 my $term = eval {
 	$ENV{"GIT_SEND_EMAIL_NOTTY"}
-		? new Term::ReadLine 'git-send-email', \*STDIN, \*STDOUT
-		: new Term::ReadLine 'git-send-email';
+		? Term::ReadLine->new('git-send-email', \*STDIN, \*STDOUT)
+		: Term::ReadLine->new('git-send-email');
 };
 if ($@) {
-	$term = new FakeTerm "$@: going non-interactive";
+	$term = FakeTerm->new("$@: going non-interactive");
 }
 
 # Behavior modification variables

From f4dc9432fd287bde9100488943baf3c6a04d90d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:49 +0200
Subject: [PATCH 10/13] send-email: lazily load modules for a big speedup
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Optimize the time git-send-email takes to do even the simplest of
things (such as serving up "-h") from around ~150ms to ~80ms-~90ms by
lazily loading the modules it requires.

Before this change Devel::TraceUse would report 99/97 used modules
under NO_GETTEXT=[|Y], respectively. Now it's 52/37. It now takes ~15s
to run t9001-send-email.sh, down from ~20s.

Changing File::Spec::Functions::{catdir,catfile} to invoking class
methods on File::Spec itself is idiomatic. See [1] for a more
elaborate explanation, the resulting code behaves the same way, just
without the now-pointless function wrapper.

1. http://lore.kernel.org/git/8735u8mmj9.fsf@evledraar.gmail.com

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 71 +++++++++++++++++++++++++--------------------
 1 file changed, 39 insertions(+), 32 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index cc1027d8774..a8949c9d313 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -19,20 +19,10 @@
 use 5.008;
 use strict;
 use warnings $ENV{GIT_PERL_FATAL_WARNINGS} ? qw(FATAL all) : ();
-use POSIX qw/strftime/;
-use Term::ReadLine;
 use Getopt::Long;
-use Text::ParseWords;
-use Term::ANSIColor;
-use File::Temp qw/ tempdir tempfile /;
-use File::Spec::Functions qw(catdir catfile);
 use Git::LoadCPAN::Error qw(:try);
-use Cwd qw(abs_path cwd);
 use Git;
 use Git::I18N;
-use Net::Domain ();
-use Net::SMTP ();
-use Git::LoadCPAN::Mail::Address;
 
 Getopt::Long::Configure qw/ pass_through /;
 
@@ -166,7 +156,6 @@ sub format_2822_time {
 		       );
 }
 
-my $have_email_valid = eval { require Email::Valid; 1 };
 my $smtp;
 my $auth;
 my $num_sent = 0;
@@ -192,14 +181,6 @@ sub format_2822_time {
 
 my $repo = eval { Git->repository() };
 my @repo = $repo ? ($repo) : ();
-my $term = eval {
-	$ENV{"GIT_SEND_EMAIL_NOTTY"}
-		? Term::ReadLine->new('git-send-email', \*STDIN, \*STDOUT)
-		: Term::ReadLine->new('git-send-email');
-};
-if ($@) {
-	$term = FakeTerm->new("$@: going non-interactive");
-}
 
 # Behavior modification variables
 my ($quiet, $dry_run) = (0, 0);
@@ -319,9 +300,9 @@ sub do_edit {
 
 # Handle Uncouth Termination
 sub signal_handler {
-
 	# Make text normal
-	print color("reset"), "\n";
+	require Term::ANSIColor;
+	print Term::ANSIColor::color("reset"), "\n";
 
 	# SMTP password masked
 	system "stty echo";
@@ -602,11 +583,13 @@ sub config_regexp {
 }
 
 sub parse_address_line {
+	require Git::LoadCPAN::Mail::Address;
 	return map { $_->format } Mail::Address->parse($_[0]);
 }
 
 sub split_addrs {
-	return quotewords('\s*,\s*', 1, @_);
+	require Text::ParseWords;
+	return Text::ParseWords::quotewords('\s*,\s*', 1, @_);
 }
 
 my %aliases;
@@ -655,10 +638,11 @@ sub parse_sendmail_aliases {
 			s/\\"/"/g foreach @addr;
 			$aliases{$alias} = \@addr
 		}}},
-	mailrc => sub { my $fh = shift; while (<$fh>) {
+	mailrc => sub {	my $fh = shift; while (<$fh>) {
 		if (/^alias\s+(\S+)\s+(.*?)\s*$/) {
+			require Text::ParseWords;
 			# spaces delimit multiple addresses
-			$aliases{$1} = [ quotewords('\s+', 0, $2) ];
+			$aliases{$1} = [ Text::ParseWords::quotewords('\s+', 0, $2) ];
 		}}},
 	pine => sub { my $fh = shift; my $f='\t[^\t]*';
 	        for (my $x = ''; defined($x); $x = $_) {
@@ -730,7 +714,8 @@ sub is_format_patch_arg {
 		opendir my $dh, $f
 			or die sprintf(__("Failed to opendir %s: %s"), $f, $!);
 
-		push @files, grep { -f $_ } map { catfile($f, $_) }
+		require File::Spec;
+		push @files, grep { -f $_ } map { File::Spec->catfile($f, $_) }
 				sort readdir $dh;
 		closedir $dh;
 	} elsif ((-f $f or -p $f) and !is_format_patch_arg($f)) {
@@ -743,7 +728,8 @@ sub is_format_patch_arg {
 if (@rev_list_opts) {
 	die __("Cannot run git format-patch from outside a repository\n")
 		unless $repo;
-	push @files, $repo->command('format-patch', '-o', tempdir(CLEANUP => 1), @rev_list_opts);
+	require File::Temp;
+	push @files, $repo->command('format-patch', '-o', File::Temp::tempdir(CLEANUP => 1), @rev_list_opts);
 }
 
 @files = handle_backup_files(@files);
@@ -780,9 +766,10 @@ sub get_patch_subject {
 if ($compose) {
 	# Note that this does not need to be secure, but we will make a small
 	# effort to have it be unique
+	require File::Temp;
 	$compose_filename = ($repo ?
-		tempfile(".gitsendemail.msg.XXXXXX", DIR => $repo->repo_path()) :
-		tempfile(".gitsendemail.msg.XXXXXX", DIR => "."))[1];
+		File::Temp::tempfile(".gitsendemail.msg.XXXXXX", DIR => $repo->repo_path()) :
+		File::Temp::tempfile(".gitsendemail.msg.XXXXXX", DIR => "."))[1];
 	open my $c, ">", $compose_filename
 		or die sprintf(__("Failed to open for writing %s: %s"), $compose_filename, $!);
 
@@ -889,6 +876,19 @@ sub get_patch_subject {
 	do_edit(@files);
 }
 
+sub term {
+	my $term = eval {
+		require Term::ReadLine;
+		$ENV{"GIT_SEND_EMAIL_NOTTY"}
+			? Term::ReadLine->new('git-send-email', \*STDIN, \*STDOUT)
+			: Term::ReadLine->new('git-send-email');
+	};
+	if ($@) {
+		$term = FakeTerm->new("$@: going non-interactive");
+	}
+	return $term;
+}
+
 sub ask {
 	my ($prompt, %arg) = @_;
 	my $valid_re = $arg{valid_re};
@@ -896,6 +896,7 @@ sub ask {
 	my $confirm_only = $arg{confirm_only};
 	my $resp;
 	my $i = 0;
+	my $term = term();
 	return defined $default ? $default : undef
 		unless defined $term->IN and defined fileno($term->IN) and
 		       defined $term->OUT and defined fileno($term->OUT);
@@ -1076,6 +1077,7 @@ sub extract_valid_address {
 	return $address if ($address =~ /^($local_part_regexp)$/);
 
 	$address =~ s/^\s*<(.*)>\s*$/$1/;
+	my $have_email_valid = eval { require Email::Valid; 1 };
 	if ($have_email_valid) {
 		return scalar Email::Valid->address($address);
 	}
@@ -1135,7 +1137,8 @@ sub validate_address_list {
 sub make_message_id {
 	my $uniq;
 	if (!defined $message_id_stamp) {
-		$message_id_stamp = strftime("%Y%m%d%H%M%S.$$", gmtime(time));
+		require POSIX;
+		$message_id_stamp = POSIX::strftime("%Y%m%d%H%M%S.$$", gmtime(time));
 		$message_id_serial = 0;
 	}
 	$message_id_serial++;
@@ -1305,6 +1308,7 @@ sub valid_fqdn {
 sub maildomain_net {
 	my $maildomain;
 
+	require Net::Domain;
 	my $domain = Net::Domain::domainname();
 	$maildomain = $domain if valid_fqdn($domain);
 
@@ -1315,6 +1319,7 @@ sub maildomain_mta {
 	my $maildomain;
 
 	for my $host (qw(mailhost localhost)) {
+		require Net::SMTP;
 		my $smtp = Net::SMTP->new($host);
 		if (defined $smtp) {
 			my $domain = $smtp->domain;
@@ -1994,13 +1999,15 @@ sub validate_patch {
 
 	if ($repo) {
 		my $hooks_path = $repo->command_oneline('rev-parse', '--git-path', 'hooks');
-		my $validate_hook = catfile($hooks_path,
+		require File::Spec;
+		my $validate_hook = File::Spec->catfile($hooks_path,
 					    'sendemail-validate');
 		my $hook_error;
 		if (-x $validate_hook) {
-			my $target = abs_path($fn);
+			require Cwd;
+			my $target = Cwd::abs_path($fn);
 			# The hook needs a correct cwd and GIT_DIR.
-			my $cwd_save = cwd();
+			my $cwd_save = Cwd::cwd();
 			chdir($repo->wc_path() or $repo->repo_path())
 				or die("chdir: $!");
 			local $ENV{"GIT_DIR"} = $repo->repo_path();

From 5a544a4e11e2a08a813215c1b9cc80cc1555c7c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:50 +0200
Subject: [PATCH 11/13] perl: lazily load some common Git.pm setup code
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Instead of unconditionally requiring modules such as File::Spec, let's
only load them when needed. This speeds up code that only needs a
subset of the features Git.pm provides.

This brings a plain invocation of "git send-email" down from 52/37
loaded modules under NO_GETTEXT=[|Y] to 39/18, and it now takes
~60-~70ms instead of ~80-~90ms. The runtime of t9001-send-email.sh
test is down to ~13s from ~15s.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 perl/Git.pm | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/perl/Git.pm b/perl/Git.pm
index 02eacef0c2a..5562c0cede2 100644
--- a/perl/Git.pm
+++ b/perl/Git.pm
@@ -11,9 +11,6 @@ package Git;
 use strict;
 use warnings $ENV{GIT_PERL_FATAL_WARNINGS} ? qw(FATAL all) : ();
 
-use File::Temp ();
-use File::Spec ();
-
 BEGIN {
 
 our ($VERSION, @ISA, @EXPORT, @EXPORT_OK);
@@ -103,12 +100,9 @@ =head1 DESCRIPTION
 =cut
 
 
-use Carp qw(carp croak); # but croak is bad - throw instead
+sub carp { require Carp; goto &Carp::carp }
+sub croak { require Carp; goto &Carp::croak }
 use Git::LoadCPAN::Error qw(:try);
-use Cwd qw(abs_path cwd);
-use IPC::Open2 qw(open2);
-use Fcntl qw(SEEK_SET SEEK_CUR);
-use Time::Local qw(timegm);
 }
 
 
@@ -191,13 +185,15 @@ sub repository {
 			$dir = undef;
 		};
 
+		require Cwd;
 		if ($dir) {
+			require File::Spec;
 			File::Spec->file_name_is_absolute($dir) or $dir = $opts{Directory} . '/' . $dir;
-			$opts{Repository} = abs_path($dir);
+			$opts{Repository} = Cwd::abs_path($dir);
 
 			# If --git-dir went ok, this shouldn't die either.
 			my $prefix = $search->command_oneline('rev-parse', '--show-prefix');
-			$dir = abs_path($opts{Directory}) . '/';
+			$dir = Cwd::abs_path($opts{Directory}) . '/';
 			if ($prefix) {
 				if (substr($dir, -length($prefix)) ne $prefix) {
 					throw Error::Simple("rev-parse confused me - $dir does not have trailing $prefix");
@@ -223,7 +219,7 @@ sub repository {
 				throw Error::Simple("fatal: Not a git repository: $dir");
 			}
 
-			$opts{Repository} = abs_path($dir);
+			$opts{Repository} = Cwd::abs_path($dir);
 		}
 
 		delete $opts{Directory};
@@ -408,10 +404,12 @@ sub command_bidi_pipe {
 	my $cwd_save = undef;
 	if ($self) {
 		shift;
-		$cwd_save = cwd();
+		require Cwd;
+		$cwd_save = Cwd::cwd();
 		_setup_git_cmd_env($self);
 	}
-	$pid = open2($in, $out, 'git', @_);
+	require IPC::Open2;
+	$pid = IPC::Open2::open2($in, $out, 'git', @_);
 	chdir($cwd_save) if $cwd_save;
 	return ($pid, $in, $out, join(' ', @_));
 }
@@ -538,7 +536,8 @@ sub get_tz_offset {
 	my $t = shift || time;
 	my @t = localtime($t);
 	$t[5] += 1900;
-	my $gm = timegm(@t);
+	require Time::Local;
+	my $gm = Time::Local::timegm(@t);
 	my $sign = qw( + + - )[ $gm <=> $t ];
 	return sprintf("%s%02d%02d", $sign, (gmtime(abs($t - $gm)))[2,1]);
 }
@@ -1340,6 +1339,7 @@ sub _temp_cache {
 		my $n = $name;
 		$n =~ s/\W/_/g; # no strange chars
 
+		require File::Temp;
 		($$temp_fd, $fname) = File::Temp::tempfile(
 			"Git_${n}_XXXXXX", UNLINK => 1, DIR => $tmpdir,
 			) or throw Error::Simple("couldn't open new temp file");
@@ -1362,9 +1362,9 @@ sub temp_reset {
 
 	truncate $temp_fd, 0
 		or throw Error::Simple("couldn't truncate file");
-	sysseek($temp_fd, 0, SEEK_SET) and seek($temp_fd, 0, SEEK_SET)
+	sysseek($temp_fd, 0, Fcntl::SEEK_SET()) and seek($temp_fd, 0, Fcntl::SEEK_SET())
 		or throw Error::Simple("couldn't seek to beginning of file");
-	sysseek($temp_fd, 0, SEEK_CUR) == 0 and tell($temp_fd) == 0
+	sysseek($temp_fd, 0, Fcntl::SEEK_CUR()) == 0 and tell($temp_fd) == 0
 		or throw Error::Simple("expected file position to be reset");
 }
 

From c95e3a3f0b8107b5dc7eac9dfdb9e5238280c9fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:51 +0200
Subject: [PATCH 12/13] send-email: move trivial config handling to Perl
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Optimize the startup time of git-send-email by using an amended
config_regexp() function to retrieve the list of config keys and
values we're interested in.

For boolean keys we can handle the [true|false] case ourselves, and
the "--get" case didn't need any parsing. Let's leave "--path" and
other "--bool" cases to "git config". I'm not bothering with the
"undef" or "" case (true and false, respectively), let's just punt on
those and others and have "git config --type=bool" handle it.

The "grep { defined } @values" here covers a rather subtle case. For
list values such as sendemail.to it is possible as with any other
config key to provide a plain "-c sendemail.to", i.e. to set the key
as a boolean true. In that case the Git::config() API will return an
empty string, but this new parser will correctly return "undef".

However, that means we can end up with "undef" in the middle of a
list. E.g. for sendemail.smtpserveroption in conjuction with
sendemail.smtpserver as a path this would have produce a warning. For
most of the other keys we'd behave the same despite the subtle change
in the value, e.g. sendemail.to would behave the same because
Mail::Address->parse() happens to return an empty list if fed
"undef". For the boolean values we were already prepared to handle
these variables being initialized as undef anyway.

This brings the runtime of "git send-email" from ~60-~70ms to a very
steady ~40ms on my test box. We now run just one "git config"
invocation on startup instead of 8, the exact number will differ based
on the local sendemail.* config. I happen to have 8 of those set.

This brings the runtime of t9001-send-email.sh from ~13s down to ~12s
for me. The change there is less impressive as many of those tests set
various config values, and we're also getting to the point of
diminishing returns for optimizing "git send-email" itself.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index a8949c9d313..57911386835 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -334,7 +334,11 @@ sub read_config {
 		my $target = $config_bool_settings{$setting};
 		my $key = "$prefix.$setting";
 		next unless exists $known_keys->{$key};
-		my $v = Git::config_bool(@repo, $key);
+		my $v = (@{$known_keys->{$key}} == 1 &&
+			 (defined $known_keys->{$key}->[0] &&
+			  $known_keys->{$key}->[0] =~ /^(?:true|false)$/s))
+			? $known_keys->{$key}->[0] eq 'true'
+			: Git::config_bool(@repo, $key);
 		next unless defined $v;
 		next if $configured->{$setting}++;
 		$$target = $v;
@@ -363,13 +367,13 @@ sub read_config {
 		my $key = "$prefix.$setting";
 		next unless exists $known_keys->{$key};
 		if (ref($target) eq "ARRAY") {
-			my @values = Git::config(@repo, $key);
-			next unless @values;
+			my @values = @{$known_keys->{$key}};
+			@values = grep { defined } @values;
 			next if $configured->{$setting}++;
 			@$target = @values;
 		}
 		else {
-			my $v = Git::config(@repo, $key);
+			my $v = $known_keys->{$key}->[0];
 			next unless defined $v;
 			next if $configured->{$setting}++;
 			$$target = $v;
@@ -381,12 +385,19 @@ sub config_regexp {
 	my ($regex) = @_;
 	my @ret;
 	eval {
-		@ret = Git::command(
+		my $ret = Git::command(
 			'config',
-			'--name-only',
+			'--null',
 			'--get-regexp',
 			$regex,
 		);
+		@ret = map {
+			# We must always return ($k, $v) here, since
+			# empty config values will be just "key\0",
+			# not "key\nvalue\0".
+			my ($k, $v) = split /\n/, $_, 2;
+			($k, $v);
+		} split /\0/, $ret;
 		1;
 	} or do {
 		# If we have no keys we're OK, otherwise re-throw
@@ -399,8 +410,10 @@ sub config_regexp {
 # parses 'bool' etc.) by only doing so for config keys that exist.
 my %known_config_keys;
 {
-	my @known_config_keys = config_regexp("^sende?mail[.]");
-	@known_config_keys{@known_config_keys} = ();
+	my @kv = config_regexp("^sende?mail[.]");
+	while (my ($k, $v) = splice @kv, 0, 2) {
+		push @{$known_config_keys{$k}} => $v;
+	}
 }
 
 # sendemail.identity yields to --identity. We must parse this

From 17530b2ed2eac62706b8bbbcf93f62866f651ffd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 28 May 2021 11:23:52 +0200
Subject: [PATCH 13/13] perl: nano-optimize by replacing Cwd::cwd() with
 Cwd::getcwd()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

It has been pointed out[1] that cwd() invokes "pwd(1)" while getcwd()
is a Perl-native XS function. For what we're using these for we can
use getcwd().

The performance difference is miniscule, we're saving on the order of
a millisecond or so, see [2] below for the benchmark. I don't think
this matters in practice for optimizing git-send-email or perl
execution (unlike the patches leading up to this one).

But let's do it regardless of that, if only so we don't have to think
about this as a low-hanging fruit anymore.

1. https://lore.kernel.org/git/20210512180517.GA11354@dcvr/
2.
    $ perl -MBenchmark=:all -MCwd -wE 'cmpthese(10000, { getcwd => sub { getcwd }, cwd => sub { cwd }, pwd => sub { system "pwd >/dev/null" }})'
                (warning: too few iterations for a reliable count)
                             Rate                  pwd                 cwd    getcwd
    pwd                     982/s                   --                -48%     -100%
    cwd                    1890/s                  92%                  --     -100%
    getcwd 10000000000000000000/s 1018000000000000000% 529000000000000064%        -

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 2 +-
 perl/Git.pm         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index 57911386835..0efe85c0b02 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -2020,7 +2020,7 @@ sub validate_patch {
 			require Cwd;
 			my $target = Cwd::abs_path($fn);
 			# The hook needs a correct cwd and GIT_DIR.
-			my $cwd_save = Cwd::cwd();
+			my $cwd_save = Cwd::getcwd();
 			chdir($repo->wc_path() or $repo->repo_path())
 				or die("chdir: $!");
 			local $ENV{"GIT_DIR"} = $repo->repo_path();
diff --git a/perl/Git.pm b/perl/Git.pm
index 5562c0cede2..090a7df63fc 100644
--- a/perl/Git.pm
+++ b/perl/Git.pm
@@ -405,7 +405,7 @@ sub command_bidi_pipe {
 	if ($self) {
 		shift;
 		require Cwd;
-		$cwd_save = Cwd::cwd();
+		$cwd_save = Cwd::getcwd();
 		_setup_git_cmd_env($self);
 	}
 	require IPC::Open2;