t7810-grep: test interaction of multiple --grep and --author options

There are tests for this interaction already. Restructure slightly and
avoid any claims about --all-match.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7810-grep.sh

@@ -495,16 +495,6 @@ test_expect_success 'log --all-match with multiple --grep uses intersection' '
 	test_cmp expect actual
 '
 
-test_expect_success 'log --grep --author implicitly uses all-match' '
-	# grep matches initial and second but not third
-	# author matches only initial and third
-	git log --author="A U Thor" --grep=s --grep=l --format=%s >actual &&
-	{
-		echo initial
-	} >expect &&
-	test_cmp expect actual
-'
-
 test_expect_success 'log with multiple --author uses union' '
 	git log --author="Thor" --author="Aster" --format=%s >actual &&
 	{
@@ -521,17 +511,33 @@ test_expect_success 'log --all-match with multiple --author still uses union' '
 	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 &&
+test_expect_success 'log --grep --author uses intersection' '
+	# grep matches only third and fourth
+	# author matches only initial and third
+	git log --author="A U Thor" --grep=r --format=%s >actual &&
 	{
-	    echo third && echo initial
+		echo third
 	} >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_expect_success 'log --grep --grep --author takes union of greps and intersects with author' '
+	# grep matches initial and second but not third
+	# author matches only initial and third
+	git log --author="A U Thor" --grep=s --grep=l --format=%s >actual &&
+	{
+		echo initial
+	} >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'log --grep --author --author takes union of authors and intersects with grep' '
+	# grep matches only initial and third
+	# author matches all but second
+	git log --author="Thor" --author="Night" --grep=i --format=%s >actual &&
+	{
+	    echo third && echo initial
+	} >expect &&
 	test_cmp expect actual
 '