Merge branch 'as/grep-quiet-no-match-exit-code-fix' into maint

"git grep -L" and "git grep --quiet -L" reported different exit
codes; this has been corrected.

* as/grep-quiet-no-match-exit-code-fix:
  git-grep: correct exit code with --quiet and -L

grep.c

@@ -1821,7 +1821,7 @@ static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int colle
 		return 0;
 
 	if (opt->status_only)
-		return 0;
+		return opt->unmatch_name_only;
 	if (opt->unmatch_name_only) {
 		/* We did not see any hit, so we want to show this */
 		show_name(opt, gs->name);

t/t7810-grep.sh

@@ -374,6 +374,11 @@ test_expect_success 'grep -L -C' '
 	test_cmp expected actual
 '
 
+test_expect_success 'grep --files-without-match --quiet' '
+	git grep --files-without-match --quiet nonexistent_string >actual &&
+	test_cmp /dev/null actual
+'
+
 cat >expected <<EOF
 file:foo mmap bar_mmap
 EOF