commit_tree: take a pointer/len pair rather than a const strbuf

diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 3119c8c523168922d42448ffbd1ee4c9647b0567..1ecdacb6fd0ceb7e43e6ec3bad018e7b6dc8100b 100755 (executable)
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -409,7 +409,7 @@ test_expect_success $PREREQ 'Valid In-Reply-To when prompting' '
        (echo "From Example <from@example.com>"
         echo "To Example <to@example.com>"
         echo ""
-       ) | env GIT_SEND_EMAIL_NOTTY=1 git send-email \
+       ) | GIT_SEND_EMAIL_NOTTY=1 git send-email \
                --smtp-server="$(pwd)/fake.sendmail" \
                $patches 2>errors &&
        ! grep "^In-Reply-To: < *>" msgtxt1