[PATCH 03/10] describe tests: always assert empty stderr from "describe"

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Invert a test added in 3291fe4072e (Add git-describe test for "verify
annotated tag names on output", 2008-03-03) to make checking that we
don't have warnings the rule rather than the exception.

There was only one case where we expected and got a warning. Let's
test for that case explicitly, and assert no warnings or other stderr
output for all the rest.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/t6120-describe.sh | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index e4fd5d567f..ef70c695be 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -21,7 +21,8 @@ check_describe () {
 	shift
 	describe_opts="$@"
 	test_expect_success "describe $describe_opts" '
-		git describe $describe_opts 2>err.actual >raw &&
+		git describe $describe_opts 2>err >raw &&
+		test_must_be_empty err &&
 		sed -e "s/-g[0-9a-f]*\$/-gHASH/" <raw >actual &&
 		echo $expect >expect &&
 		test_cmp expect actual
@@ -122,20 +123,17 @@ test_expect_success 'describe --contains defaults to HEAD without commit-ish' '
 '
 
 check_describe tags/A --all A^0
-test_expect_success 'no warning was displayed for A' '
-	test_must_be_empty err.actual
-'
 
-test_expect_success 'rename tag A to Q locally' '
-	mv .git/refs/tags/A .git/refs/tags/Q
-'
-cat - >err.expect <<EOF
-warning: tag 'Q' is externally known as 'A'
-EOF
-check_describe A-8-gHASH HEAD
-test_expect_success 'warning was displayed for Q' '
-	test_cmp err.expect err.actual
-'
+test_expect_success 'renaming tag A to Q locally produces a warning' "
+	mv .git/refs/tags/A .git/refs/tags/Q &&
+	git describe HEAD 2>actual >out &&
+	cat >expected <<-\EOF &&
+	warning: tag 'Q' is externally known as 'A'
+	EOF
+	test_cmp expected actual &&
+	grep -E '^A-8-g[0-9a-f]+$' out
+"
+
 test_expect_success 'misnamed annotated tag forces long output' '
 	description=$(git describe --no-long Q^0) &&
 	expr "$description" : "A-0-g[0-9a-f]*$" &&
-- 
2.31.0.rc0.116.g45ec00aa00