'
+cat > expect << EOF
+---
+ file | 16 ++++++++++++++++
+ 1 files changed, 16 insertions(+), 0 deletions(-)
+
+diff --git a/file b/file
+index 40f36c6..2dc5c23 100644
+--- a/file
++++ b/file
+@@ -13,4 +13,20 @@ C
+ 10
+ D
+ E
+ F
++5
+EOF
+
+test_expect_success 'format-patch respects -U' '
+
+ git format-patch -U4 -2 &&
+ sed -e "1,/^$/d" -e "/^+5/q" < 0001-This-is-an-excessively-long-subject-line-for-a-messa.patch > output &&
+ test_cmp expect output
+
+'
+
test_done