}
'
+test_expect_success '--check --exit-code returns 0 for no difference' '
+
+ git diff --check --exit-code
+
+'
+
+test_expect_success '--check --exit-code returns 1 for a clean difference' '
+
+ echo "good" > a &&
+ git diff --check --exit-code
+ test $? = 1
+
+'
+
+test_expect_success '--check --exit-code returns 3 for a dirty difference' '
+
+ echo "bad " >> a &&
+ git diff --check --exit-code
+ test $? = 3
+
+'
+
+test_expect_success '--check with --no-pager returns 2 for dirty difference' '
+
+ git --no-pager diff --check
+ test $? = 2
+
+'
+
+
+test_expect_success 'check should test not just the last line' '
+ echo "" >>a &&
+ git --no-pager diff --check
+ test $? = 2
+
+'
+
+test_expect_success 'check detects leftover conflict markers' '
+ git reset --hard &&
+ git checkout HEAD^ &&
+ echo binary >>b &&
+ git commit -m "side" b &&
+ test_must_fail git merge master &&
+ git add b && (
+ git --no-pager diff --cached --check >test.out
+ test $? = 2
+ ) &&
+ test 3 = $(grep "conflict marker" test.out | wc -l) &&
+ git reset --hard
+'
+
test_done