Re: [PATCH] send-email: Use setlocale in addition to $ENV{LC_ALL} to set locale

[Junio C Hamano <junkio@cox.net>]

I was reviewing old log and noticed this topic has never been
resolved.  Your proposal was to use POSIX::setlocale(), and
Eric's counter-proposal was to mimic what 822-date script does,
doing it by hand without mucking with locales, and the
discussion seemed to have died there.  Does this still need to
be addressed?

My gut feeling is that it would probably be less problematic if
we do not muck with locales at all (so drop POSIX::strftime as
well).

So maybe something like this (totally untested)?

-- >8 --
[PATCH] do not use locale specific strftime when preparing 2822 date

Signed-off-by: Junio C Hamano <junkio@cox.net>
---
diff --git a/git-send-email.perl b/git-send-email.perl
index c5d9e73..bc42761 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -23,8 +23,43 @@ use Getopt::Long;
 use Data::Dumper;
 
 # most mail servers generate the Date: header, but not all...
-$ENV{LC_ALL} = 'C';
-use POSIX qw/strftime/;
+sub format_2822_time {
+	my ($time) = @_;
+	my @localtm = localtime($time);
+	my @gmttm = gmtime($time);
+	my $localmin = $localtm[1] + $localtm[2] * 60;
+	my $gmtmin = $gmttm[1] + $gmttm[2] * 60;
+	if ($localtm[0] != $gmttm[0]) {
+		die "local zone differs from GMT by a non-minute interval\n";
+	}
+	if ((($gmttm[6] + 1) % 7) == $localtm[6]) {
+		$localmin += 1440;
+	} elsif ((($gmttm[6] - 1) % 7) == $localtm[6]) {
+		$localmin -= 1440;
+	} elsif ($gmttm[6] != $localtm[6]) {
+		die "local time offset greater than or equal to 24 hours\n";
+	}
+	my $offset = $localmin - $gmtmin;
+	my $offhour = $offset / 60;
+	my $offmin = abs($offset % 60);
+	if (abs($offhour) >= 24) {
+		die ("local time offset greater than or equal to 24 hours\n");
+	}
+
+	return sprintf("%s, %2d %s %d %02d:%02d:%02d %s%02d%02d",
+		       qw(Sun Mon Tue Wed Thu Fri Sat)[$localtm[6]],
+		       $localtm[3],
+		       qw(Jan Feb Mar Apr May Jun
+			  Jul Aug Sep Oct Nov Dec)[$localtm[4]],
+		       $localtm[5]+1900,
+		       $localtm[2],
+		       $localtm[1],
+		       $localtm[0],
+		       ($offset >= 0) ? '+' : '-',
+		       abs($offhour),
+		       $offmin,
+		       );
+}
 
 my $have_email_valid = eval { require Email::Valid; 1 };
 my $smtp;
@@ -371,7 +405,7 @@ sub send_message
 	my @recipients = unique_email_list(@to);
 	my $to = join (",\n\t", @recipients);
 	@recipients = unique_email_list(@recipients,@cc,@bcclist);
-	my $date = strftime('%a, %d %b %Y %H:%M:%S %z', localtime($time++));
+	my $date = format_2822_time($time++);
 	my $gitversion = '@@GIT_VERSION@@';
 	if ($gitversion =~ m/..GIT_VERSION../) {
 	    $gitversion = `git --version`;