+test_expect_success 'log with multiple --author uses union' '
+ git log --author="Thor" --author="Aster" --format=%s >actual &&
+ {
+ echo third && echo second && echo initial
+ } >expect &&
+ test_cmp expect actual
+'
+
+test_expect_success 'log with --grep and multiple --author uses all-match' '
+ git log --author="Thor" --author="Night" --grep=i --format=%s >actual &&
+ {
+ echo third && echo initial
+ } >expect &&
+ test_cmp expect actual
+'
+
+test_expect_success 'log with --grep and multiple --author uses all-match' '
+ git log --author="Thor" --author="Night" --grep=q --format=%s >actual &&
+ >expect &&
+ test_cmp expect actual
+'
+