git-send-email.perl: make initial In-Reply-To apply only to first email

diff --git a/git-send-email.perl b/git-send-email.perl
index f68ed5a5d3208eb0669d7dc1289f40c567e077c7..fe6b8485cd0c0781908cf83e377be048cfc0544b 100755 (executable)
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -1319,7 +1319,8 @@ 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 $reply_to || length($reply_to) == 0 ||
+               $message_num == 1)) {
                $reply_to = $message_id;
                if (length $references > 0) {
                        $references .= "\n $message_id";