send-email: add test for duplicate utf8 name

Verify that author name is not duplicated if it matches sender, even
if it is in utf8 (the test expects a failure that will be fixed in
the next patch).

Signed-off-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: mstsirkin

t/t9001-send-email.sh

@@ -956,6 +956,20 @@ test_expect_success $PREREQ 'utf8 author is correctly passed on' '
 	grep "^From: Füñný Nâmé <[email protected]>" msgtxt1
 '
 
+test_expect_failure $PREREQ 'utf8 sender is not duplicated' '
+	clean_fake_sendmail &&
+	test_commit weird_sender &&
+	test_when_finished "git reset --hard HEAD^" &&
+	git commit --amend --author "Füñný Nâmé <[email protected]>" &&
+	git format-patch --stdout -1 >funny_name.patch &&
+	git send-email --from="Füñný Nâmé <[email protected]>" \
+	  [email protected] \
+	  --smtp-server="$(pwd)/fake.sendmail" \
+	  funny_name.patch &&
+	grep "^From: " msgtxt1 >msgfrom &&
+	test_line_count = 1 msgfrom
+'
+
 test_expect_success $PREREQ 'sendemail.composeencoding works' '
 	clean_fake_sendmail &&
 	git config sendemail.composeencoding iso-8859-1 &&