Merge branch 'jc/maint-log-grep-all-match-1' into maint

* jc/maint-log-grep-all-match-1:
  grep.c: make two symbols really file-scope static this time
  t7810-grep: test --all-match with multiple --grep and --author options
  t7810-grep: test interaction of multiple --grep and --author options
  t7810-grep: test multiple --author with --all-match
  t7810-grep: test multiple --grep with and without --all-match
  t7810-grep: bring log --grep tests in common form
  grep.c: mark private file-scope symbols as static
  log: document use of multiple commit limiting options
  log --grep/--author: honor --all-match honored for multiple --grep patterns
  grep: show --debug output only once
  grep: teach --debug option to dump the parse tree

t/t7810-grep.sh

@@ -424,31 +424,41 @@ test_expect_success 'log grep setup' '
 
 test_expect_success 'log grep (1)' '
 	git log --author=author --pretty=tformat:%s >actual &&
-	( echo third ; echo initial ) >expect &&
+	{
+		echo third && echo initial
+	} >expect &&
 	test_cmp expect actual
 '
 
 test_expect_success 'log grep (2)' '
 	git log --author=" * " -F --pretty=tformat:%s >actual &&
-	( echo second ) >expect &&
+	{
+		echo second
+	} >expect &&
 	test_cmp expect actual
 '
 
 test_expect_success 'log grep (3)' '
 	git log --author="^A U" --pretty=tformat:%s >actual &&
-	( echo third ; echo initial ) >expect &&
+	{
+		echo third && echo initial
+	} >expect &&
 	test_cmp expect actual
 '
 
 test_expect_success 'log grep (4)' '
 	git log --author="frotz\.com>$" --pretty=tformat:%s >actual &&
-	( echo second ) >expect &&
+	{
+		echo second
+	} >expect &&
 	test_cmp expect actual
 '
 
 test_expect_success 'log grep (5)' '
 	git log --author=Thor -F --pretty=tformat:%s >actual &&
-	( echo third ; echo initial ) >expect &&
+	{
+		echo third && echo initial
+	} >expect &&
 	test_cmp expect actual
 '
 
@@ -458,11 +468,19 @@ test_expect_success 'log grep (6)' '
 	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_expect_success 'log with multiple --grep uses union' '
+	git log --grep=i --grep=r --format=%s >actual &&
+	{
+		echo fourth && echo third && echo initial
+	} >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'log --all-match with multiple --grep uses intersection' '
+	git log --all-match --grep=i --grep=r --format=%s >actual &&
+	{
+		echo third
+	} >expect &&
 	test_cmp expect actual
 '
 
@@ -474,7 +492,47 @@ test_expect_success 'log with multiple --author uses union' '
 	test_cmp expect actual
 '
 
-test_expect_success 'log with --grep and multiple --author uses all-match' '
+test_expect_success 'log --all-match with multiple --author still uses union' '
+	git log --all-match --author="Thor" --author="Aster" --format=%s >actual &&
+	{
+	    echo third && echo second && echo initial
+	} >expect &&
+	test_cmp expect 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
+	} >expect &&
+	test_cmp expect actual
+'
+
+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 ---all-match -grep --author --author still takes union of authors and intersects with grep' '
+	# grep matches only initial and third
+	# author matches all but second
+	git log --all-match --author="Thor" --author="Night" --grep=i --format=%s >actual &&
+	{
+	    echo third && 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
@@ -482,9 +540,13 @@ test_expect_success 'log with --grep and multiple --author uses all-match' '
 	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 --all-match --grep --grep --author takes intersection' '
+	# grep matches only third
+	# author matches only initial and third
+	git log --all-match --author="A U Thor" --grep=i --grep=r --format=%s >actual &&
+	{
+		echo third
+	} >expect &&
 	test_cmp expect actual
 '