address: use Email::Address::XS if available

Email::Address::XS is a dependency of modern versions of Email::MIME,
so it's likely loaded and installed on newer systems, already;
and capable of handling more corner-cases than our pure-Perl
fallback.

We still fallback to the imperfect-but-good-enough-in-practice
pure-Perl code while avoiding the non-XS Email::Address (which
was susceptible to DoS attacks (CVE-2015-7686)).  We just need
to keep "git fast-import" happy.

4 files changed, 98 insertions, 52 deletions

diff --git a/MANIFEST b/MANIFEST
index edbbbfad..3a301ee7 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -81,6 +81,7 @@ examples/unsubscribe.milter
 examples/unsubscribe.psgi
 examples/varnish-4.vcl
 lib/PublicInbox/Address.pm
+lib/PublicInbox/AddressPP.pm
 lib/PublicInbox/Admin.pm
 lib/PublicInbox/AdminEdit.pm
 lib/PublicInbox/AltId.pm
diff --git a/lib/PublicInbox/Address.pm b/lib/PublicInbox/Address.pm
index a58d1eff..433b36eb 100644
--- a/lib/PublicInbox/Address.pm
+++ b/lib/PublicInbox/Address.pm
@@ -4,35 +4,27 @@ package PublicInbox::Address;
 use strict;
 use warnings;
 
-# very loose regexes, here.  We don't need RFC-compliance,
-# just enough to make thing sanely displayable and pass to git
+sub xs_emails { map { $_->address() } parse_email_addresses($_[0]) }
 
-sub emails {
-        ($_[0] =~ /([\w\.\+=\?"\(\)\-!#\$%&'\*\/\^\`\|\{\}~]+\@[\w\.\-\(\)]+)
-                (?:\s[^>]*)?>?\s*(?:\(.*?\))?(?:,\s*|\z)/gx)
+sub xs_names {
+        map {
+                my $n = $_->name;
+                $n = $_->user if $n eq $_->address;
+                $n;
+        } parse_email_addresses($_[0]);
 }
 
-sub names {
-        my @p = split(/<?([^@<>]+)\@[\w\.\-]+>?\s*(\(.*?\))?(?:,\s*|\z)/,
-                        $_[0]);
-        my @ret;
-        for (my $i = 0; $i <= $#p;) {
-                my $phrase = $p[$i++];
-                $phrase =~ tr/\r\n\t / /s;
-                $phrase =~ s/\A['"\s]*//;
-                $phrase =~ s/['"\s]*\z//;
-                my $user = $p[$i++] // '';
-                my $comment = $p[$i++] // '';
-                if ($phrase =~ /\S/) {
-                        $phrase =~ s/\@\S+\z//;
-                        push @ret, $phrase;
-                } elsif ($comment =~ /\A\((.*?)\)\z/) {
-                        push @ret, $1;
-                } else {
-                        push @ret, $user;
-                }
-        }
-        @ret;
+eval {
+        require Email::Address::XS;
+        Email::Address::XS->import(qw(parse_email_addresses));
+        *emails = \&xs_emails;
+        *names = \&xs_names;
+};
+
+if ($@) {
+        require PublicInbox::AddressPP;
+        *emails = \&PublicInbox::AddressPP::emails;
+        *names = \&PublicInbox::AddressPP::names;
 }
 
 1;
diff --git a/lib/PublicInbox/AddressPP.pm b/lib/PublicInbox/AddressPP.pm
new file mode 100644
index 00000000..cd7aedb9
--- /dev/null
+++ b/lib/PublicInbox/AddressPP.pm
@@ -0,0 +1,38 @@
+# Copyright (C) 2016-2019 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+package PublicInbox::AddressPP;
+use strict;
+
+# very loose regexes, here.  We don't need RFC-compliance,
+# just enough to make thing sanely displayable and pass to git
+# We favor Email::Address::XS for conformance if available
+
+sub emails {
+        ($_[0] =~ /([\w\.\+=\?"\(\)\-!#\$%&'\*\/\^\`\|\{\}~]+\@[\w\.\-\(\)]+)
+                (?:\s[^>]*)?>?\s*(?:\(.*?\))?(?:,\s*|\z)/gx)
+}
+
+sub names {
+        my @p = split(/<?([^@<>]+)\@[\w\.\-]+>?\s*(\(.*?\))?(?:,\s*|\z)/,
+                        $_[0]);
+        my @ret;
+        for (my $i = 0; $i <= $#p;) {
+                my $phrase = $p[$i++];
+                $phrase =~ tr/\r\n\t / /s;
+                $phrase =~ s/\A['"\s]*//;
+                $phrase =~ s/['"\s]*\z//;
+                my $user = $p[$i++] // '';
+                my $comment = $p[$i++] // '';
+                if ($phrase =~ /\S/) {
+                        $phrase =~ s/\@\S+\z//;
+                        push @ret, $phrase;
+                } elsif ($comment =~ /\A\((.*?)\)\z/) {
+                        push @ret, $1;
+                } else {
+                        push @ret, $user;
+                }
+        }
+        @ret;
+}
+
+1;
diff --git a/t/address.t b/t/address.t
index 2a287102..e7c0d6a8 100644
--- a/t/address.t
+++ b/t/address.t
@@ -5,34 +5,49 @@ use warnings;
 use Test::More;
 use_ok 'PublicInbox::Address';
 
-is_deeply([qw(e@example.com e@example.org)],
-        [PublicInbox::Address::emails('User <e@example.com>, e@example.org')],
-        'address extraction works as expected');
-
-is_deeply(['user@example.com'],
-        [PublicInbox::Address::emails('<user@example.com (Comment)>')],
-        'comment after domain accepted before >');
-
-my @names = PublicInbox::Address::names(
-        'User <e@e>, e@e, "John A. Doe" <j@d>, <x@x>, <y@x> (xyz), '.
-        'U Ser <u@x> (do not use)');
-is_deeply(\@names, ['User', 'e', 'John A. Doe', 'x', 'xyz', 'U Ser'],
-        'name extraction works as expected');
-
-@names = PublicInbox::Address::names('"user@example.com" <user@example.com>');
-is_deeply(['user'], \@names, 'address-as-name extraction works as expected');
-
-
-{
-        my $backwards = 'u@example.com (John Q. Public)';
-        @names = PublicInbox::Address::names($backwards);
-        is_deeply(\@names, ['John Q. Public'], 'backwards name OK');
-        my @emails = PublicInbox::Address::emails($backwards);
-        is_deeply(\@emails, ['u@example.com'], 'backwards emails OK');
+sub test_pkg {
+        my ($pkg) = @_;
+        my $emails = \&{"${pkg}::emails"};
+        my $names = \&{"${pkg}::names"};
+
+        is_deeply([qw(e@example.com e@example.org)],
+                [$emails->('User <e@example.com>, e@example.org')],
+                'address extraction works as expected');
+
+        is_deeply(['user@example.com'],
+                [$emails->('<user@example.com (Comment)>')],
+                'comment after domain accepted before >');
+
+        my @names = $names->(
+                'User <e@e>, e@e, "John A. Doe" <j@d>, <x@x>, <y@x> (xyz), '.
+                'U Ser <u@x> (do not use)');
+        is_deeply(\@names, ['User', 'e', 'John A. Doe', 'x', 'xyz', 'U Ser'],
+                'name extraction works as expected');
+
+        @names = $names->('"user@example.com" <user@example.com>');
+        is_deeply(['user'], \@names,
+                'address-as-name extraction works as expected');
+
+        {
+                my $backwards = 'u@example.com (John Q. Public)';
+                @names = $names->($backwards);
+                is_deeply(\@names, ['John Q. Public'], 'backwards name OK');
+                my @emails = $emails->($backwards);
+                is_deeply(\@emails, ['u@example.com'], 'backwards emails OK');
+        }
+
+        @names = $names->('"Quote Unneeded" <user@example.com>');
+        is_deeply(['Quote Unneeded'], \@names, 'extra quotes dropped');
 }
 
+test_pkg('PublicInbox::Address');
 
-@names = PublicInbox::Address::names('"Quote Unneeded" <user@example.com>');
-is_deeply(['Quote Unneeded'], \@names, 'extra quotes dropped');
+SKIP: {
+        if ($INC{'PublicInbox/AddressPP.pm'}) {
+                skip 'Email::Address::XS missing', 8;
+        }
+        use_ok 'PublicInbox::AddressPP';
+        test_pkg('PublicInbox::AddressPP');
+}
 
 done_testing;