completion: fix multiple command removals

diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index d4bd1522fe2e6e94578b2d6f709005c7a271b4b0..561796f2809c38d3b5229abd4359f5b72141839e 100755 (executable)
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -382,7 +382,7 @@ corrupt_graph_and_verify() {
        test_when_finished mv commit-graph-backup $objdir/info/commit-graph &&
        cp $objdir/info/commit-graph commit-graph-backup &&
        printf "$data" | dd of="$objdir/info/commit-graph" bs=1 seek="$pos" conv=notrunc &&
-       dd of="$objdir/info/commit-graph" bs=1 seek="$zero_pos" count=0 &&
+       dd of="$objdir/info/commit-graph" bs=1 seek="$zero_pos" if=/dev/null &&
        generate_zero_bytes $(($orig_size - $zero_pos)) >>"$objdir/info/commit-graph" &&
        test_must_fail git commit-graph verify 2>test_err &&
        grep -v "^+" test_err >err &&