send-email: rename variable for clarity

The SMTP protocol has both, the 'Reply-To' and the 'In-Reply-To' header
fields. We only use the latter. To avoid confusion, rename the variable
for it.

Signed-off-by: Christian Ludwig <chrissicool@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: chrissicool

git-send-email.perl

@@ -166,13 +166,13 @@ sub format_2822_time {
 
 # Variables we fill in automatically, or via prompting:
 my (@to,$no_to,@initial_to,@cc,$no_cc,@initial_cc,@bcclist,$no_bcc,@xh,
-	$initial_reply_to,$initial_subject,@files,
+	$initial_in_reply_to,$initial_subject,@files,
 	$author,$sender,$smtp_authpass,$annotate,$use_xmailer,$compose,$time);
 
 my $envelope_sender;
 
 # Example reply to:
-#$initial_reply_to = ''; #<20050203173208.GA23964@foobar.com>';
+#$initial_in_reply_to = ''; #<20050203173208.GA23964@foobar.com>';
 
 my $repo = eval { Git->repository() };
 my @repo = $repo ? ($repo) : ();
@@ -314,7 +314,7 @@ sub signal_handler {
     if !$help and $dump_aliases and @ARGV;
 $rc = GetOptions(
 		    "sender|from=s" => \$sender,
-                    "in-reply-to=s" => \$initial_reply_to,
+                    "in-reply-to=s" => \$initial_in_reply_to,
 		    "subject=s" => \$initial_subject,
 		    "to=s" => \@initial_to,
 		    "to-cmd=s" => \$to_cmd,
@@ -676,7 +676,7 @@ sub get_patch_subject {
 
 	my $tpl_sender = $sender || $repoauthor || $repocommitter || '';
 	my $tpl_subject = $initial_subject || '';
-	my $tpl_reply_to = $initial_reply_to || '';
+	my $tpl_in_reply_to = $initial_in_reply_to || '';
 
 	print $c <<EOT1, Git::prefix_lines("GIT: ", __ <<EOT2), <<EOT3;
 From $tpl_sender # This line is ignored.
@@ -689,7 +689,7 @@ sub get_patch_subject {
 EOT2
 From: $tpl_sender
 Subject: $tpl_subject
-In-Reply-To: $tpl_reply_to
+In-Reply-To: $tpl_in_reply_to
 
 EOT3
 	for my $f (@files) {
@@ -728,7 +728,7 @@ sub get_patch_subject {
 		$sender = delete($parsed_email{'From'});
 	}
 	if ($parsed_email{'In-Reply-To'}) {
-		$initial_reply_to = delete($parsed_email{'In-Reply-To'});
+		$initial_in_reply_to = delete($parsed_email{'In-Reply-To'});
 	}
 	if ($parsed_email{'Subject'}) {
 		$initial_subject = delete($parsed_email{'Subject'});
@@ -911,16 +911,16 @@ sub expand_one_alias {
 @initial_cc = process_address_list(@initial_cc);
 @bcclist = process_address_list(@bcclist);
 
-if ($thread && !defined $initial_reply_to && $prompting) {
-	$initial_reply_to = ask(
+if ($thread && !defined $initial_in_reply_to && $prompting) {
+	$initial_in_reply_to = ask(
 		__("Message-ID to be used as In-Reply-To for the first email (if any)? "),
 		default => "",
 		valid_re => qr/\@.*\./, confirm_only => 1);
 }
-if (defined $initial_reply_to) {
-	$initial_reply_to =~ s/^\s*<?//;
-	$initial_reply_to =~ s/>?\s*$//;
-	$initial_reply_to = "<$initial_reply_to>" if $initial_reply_to ne '';
+if (defined $initial_in_reply_to) {
+	$initial_in_reply_to =~ s/^\s*<?//;
+	$initial_in_reply_to =~ s/>?\s*$//;
+	$initial_in_reply_to = "<$initial_in_reply_to>" if $initial_in_reply_to ne '';
 }
 
 if (!defined $smtp_server) {
@@ -940,7 +940,7 @@ sub expand_one_alias {
 }
 
 # Variables we set as part of the loop over files
-our ($message_id, %mail, $subject, $reply_to, $references, $message,
+our ($message_id, %mail, $subject, $in_reply_to, $references, $message,
 	$needs_confirm, $message_num, $ask_default);
 
 sub extract_valid_address {
@@ -1349,9 +1349,9 @@ sub send_message {
 	if ($use_xmailer) {
 		$header .= "X-Mailer: git-send-email $gitversion\n";
 	}
-	if ($reply_to) {
+	if ($in_reply_to) {
 
-		$header .= "In-Reply-To: $reply_to\n";
+		$header .= "In-Reply-To: $in_reply_to\n";
 		$header .= "References: $references\n";
 	}
 	if (@xh) {
@@ -1528,8 +1528,8 @@ sub send_message {
 	return 1;
 }
 
-$reply_to = $initial_reply_to;
-$references = $initial_reply_to || '';
+$in_reply_to = $initial_in_reply_to;
+$references = $initial_in_reply_to || '';
 $subject = $initial_subject;
 $message_num = 0;
 
@@ -1739,9 +1739,9 @@ sub send_message {
 
 	# set up for the next message
 	if ($thread && $message_was_sent &&
-		($chain_reply_to || !defined $reply_to || length($reply_to) == 0 ||
+		($chain_reply_to || !defined $in_reply_to || length($in_reply_to) == 0 ||
 		$message_num == 1)) {
-		$reply_to = $message_id;
+		$in_reply_to = $message_id;
 		if (length $references > 0) {
 			$references .= "\n $message_id";
 		} else {