[PATCH] progress.c tests: fix breakage with COLUMNS != 80

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

The tests added in 2bb74b53a49 (Test the progress display, 2019-09-16)
broke under anything except COLUMNS=80, i.e. when running them under
the "-v" mode under a differently sized terminal.

Let's set the expected number of COLUMNS at the start of the test to
fix that bug. It's handy not do do this in test-progress.c itself, in
case we'd like to test for a different number of COLUMNS, either
manually or in a future test.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/t0500-progress-display.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/t/t0500-progress-display.sh b/t/t0500-progress-display.sh
index 22058b503ac..66c092a0fe3 100755
--- a/t/t0500-progress-display.sh
+++ b/t/t0500-progress-display.sh
@@ -8,6 +8,11 @@ show_cr () {
 	tr '\015' Q | sed -e "s/Q/<CR>\\$LF/g"
 }
 
+test_expect_success 'setup COLUMNS' '
+	COLUMNS=80 &&
+	export COLUMNS
+'
+
 test_expect_success 'simple progress display' '
 	cat >expect <<-\EOF &&
 	Working hard: 1<CR>
-- 
2.32.0.595.g55105f1e212