test_cmp expect actual
'
+test_expect_success 'set up %S tests' '
+ git checkout --orphan source-a &&
+ test_commit one &&
+ test_commit two &&
+ git checkout -b source-b HEAD^ &&
+ test_commit three
+'
+
+test_expect_success 'log --format=%S paints branch names' '
+ cat >expect <<-\EOF &&
+ source-b
+ source-a
+ source-b
+ EOF
+ git log --format=%S source-a source-b >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'log --format=%S paints tag names' '
+ git tag -m tagged source-tag &&
+ cat >expect <<-\EOF &&
+ source-tag
+ source-a
+ source-tag
+ EOF
+ git log --format=%S source-tag source-a >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'log --format=%S paints symmetric ranges' '
+ cat >expect <<-\EOF &&
+ source-b
+ source-a
+ EOF
+ git log --format=%S source-a...source-b >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success '%S in git log --format works with other placeholders (part 1)' '
+ git log --format="source-b %h" source-b >expect &&
+ git log --format="%S %h" source-b >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success '%S in git log --format works with other placeholders (part 2)' '
+ git log --format="%h source-b" source-b >expect &&
+ git log --format="%h %S" source-b >actual &&
+ test_cmp expect actual
+'
+
test_done