Merge branch 'dd/t6300-wo-gpg-fix' into maint

Test fix.

* dd/t6300-wo-gpg-fix:
  t6300: check for cat-file exit status code
  t6300: don't run cat-file on non-existent object

t/t6300-for-each-ref.sh

@@ -59,18 +59,25 @@ test_atom() {
 	# Automatically test "contents:size" atom after testing "contents"
 	if test "$2" = "contents"
 	then
-		case $(git cat-file -t "$ref") in
+		# for commit leg, $3 is changed there
+		expect=$(printf '%s' "$3" | wc -c)
+		test_expect_${4:-success} $PREREQ "basic atom: $1 contents:size" '
+			type=$(git cat-file -t "$ref") &&
+			case $type in
 			tag)
 				# We cannot use $3 as it expects sanitize_pgp to run
-			expect=$(git cat-file tag $ref | tail -n +6 | wc -c) ;;
+				git cat-file tag $ref >out &&
+				expect=$(tail -n +6 out | wc -c) &&
+				rm -f out ;;
 			tree | blob)
-			expect='' ;;
+				expect="" ;;
 			commit)
-			expect=$(printf '%s' "$3" | wc -c) ;;
-		esac
+				: "use the calculated expect" ;;
+			*)
+				BUG "unknown object type" ;;
+			esac &&
 			# Leave $expect unquoted to lose possible leading whitespaces
-		echo $expect >expected
-		test_expect_${4:-success} $PREREQ "basic atom: $1 contents:size" '
+			echo $expect >expected &&
 			git for-each-ref --format="%(contents:size)" "$ref" >actual &&
 			test_cmp expected actual
 		'