send-email: teach sanitize_address to do rfc2047 quoting

Without this patch I'm not able to properly send emails as I have a
non-ascii character in my name.

I removed the _rfc822 suffix from the function name as it now does more
than rfc822 quoting.

I dug through rfc822 to do the double quoting right.  Only if that is not
possible rfc2047 quoting is applied.

Signed-off-by: Uwe Kleine-K,Av(Bnig <ukleinek@informatik.uni-freiburg.de>
Cc: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-send-email.perl

@@ -289,7 +289,7 @@ sub expand_aliases {
 }
 
 @to = expand_aliases(@to);
-@to = (map { sanitize_address_rfc822($_) } @to);
+@to = (map { sanitize_address($_) } @to);
 @initial_cc = expand_aliases(@initial_cc);
 @bcclist = expand_aliases(@bcclist);
 
@@ -459,22 +459,41 @@ sub unquote_rfc2047 {
 	return "$_";
 }
 
-# If an address contains a . in the name portion, the name must be quoted.
-sub sanitize_address_rfc822
+# use the simplest quoting being able to handle the recipient
+sub sanitize_address
 {
 	my ($recipient) = @_;
-	my ($recipient_name) = ($recipient =~ /^(.*?)\s+</);
-	if ($recipient_name && $recipient_name =~ /\./ && $recipient_name !~ /^".*"$/) {
-		my ($name, $addr) = ($recipient =~ /^(.*?)(\s+<.*)/);
-		$recipient = "\"$name\"$addr";
+	my ($recipient_name, $recipient_addr) = ($recipient =~ /^(.*?)\s*(<.*)/);
+
+	if (not $recipient_name) {
+		return "$recipient";
+	}
+
+	# if recipient_name is already quoted, do nothing
+	if ($recipient_name =~ /^(".*"|=\?utf-8\?q\?.*\?=)$/) {
+		return $recipient;
+	}
+
+	# rfc2047 is needed if a non-ascii char is included
+	if ($recipient_name =~ /[^[:ascii:]]/) {
+		$recipient_name =~ s/([^-a-zA-Z0-9!*+\/])/sprintf("=%02X", ord($1))/eg;
+		$recipient_name =~ s/(.*)/=\?utf-8\?q\?$1\?=/;
 	}
-	return $recipient;
+
+	# double quotes are needed if specials or CTLs are included
+	elsif ($recipient_name =~ /[][()<>@,;:\\".\000-\037\177]/) {
+		$recipient_name =~ s/(["\\\r])/\\$1/;
+		$recipient_name = "\"$recipient_name\"";
+	}
+
+	return "$recipient_name $recipient_addr";
+
 }
 
 sub send_message
 {
 	my @recipients = unique_email_list(@to);
-	@cc = (map { sanitize_address_rfc822($_) } @cc);
+	@cc = (map { sanitize_address($_) } @cc);
 	my $to = join (",\n\t", @recipients);
 	@recipients = unique_email_list(@recipients,@cc,@bcclist);
 	@recipients = (map { extract_valid_address($_) } @recipients);
@@ -489,7 +508,7 @@ sub send_message
 	if ($cc ne '') {
 		$ccline = "\nCc: $cc";
 	}
-	$from = sanitize_address_rfc822($from);
+	$from = sanitize_address($from);
 	make_message_id();
 
 	my $header = "From: $from