[PATCH v2 5/6] send-email: fix non-threaded mails

After commit 3e0c4ff (send-email: respect in-reply-to regardless of
threading, 2009-03-01) the variable $thread was only used for prompting
for an "In-Reply-To", but not for controlling whether the "In-Reply-To"
and "References" fields should be written into the email.

Thus these fields were always used beginning with the second mail and it
was not possible to produce non-threaded mails anymore until commit
15da108 ("send-email: 'References:' should only reference what is sent",
2009-04-13), which introduced a regression with the side effect to make
it possible again when --no-chain-reply-to was set.

Signed-off-by: Markus Heidelberg <redacted>
---

Differences to v1:
* patch context in the test:
  "git send-email" instead of "!git send-email"

 git-send-email.perl   |    5 ++++-
 t/t9001-send-email.sh |    2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index c11a245..be63ea7 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl

@@ -1142,7 +1142,10 @@ foreach my $t (@files) {
 	my $message_was_sent = send_message();
 
 	# set up for the next message
-	if ($message_was_sent and $chain_reply_to || !defined $reply_to || length($reply_to) == 0) {
+	if ($message_was_sent and $thread and
+			$chain_reply_to || !defined $reply_to || length($reply_to) == 0) {
+		# with --chain-reply-to every time
+		# else only after the first mail (and only if --in-reply-to was not specified)
 		$reply_to = $message_id;
 		if (length $references > 0) {
 			$references .= "\n $message_id";

diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 4a4fa7f..87bbbe7 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh

@@ -621,7 +621,7 @@ test_expect_success 'in-reply-to but no threading' '
 	grep "In-Reply-To: <in-reply-id@example.com>"
 '
 
-test_expect_failure 'no in-reply-to and no threading' '
+test_expect_success 'no in-reply-to and no threading' '
 	git send-email \
 		--dry-run \
 		--from="Example <nobody@example.com>" \

-- 
1.6.3.2.220.gb421