completion: refactor __gitcomp related tests

diff --git a/t/t4024-diff-optimize-common.sh b/t/t4024-diff-optimize-common.sh
index 3c66102f7ade654bb2ee0e0d732f86a301d1cb1e..c4d733f5db6a4d390762505b770954cdbf6cc82f 100755 (executable)
--- a/t/t4024-diff-optimize-common.sh
+++ b/t/t4024-diff-optimize-common.sh
@@ -150,7 +150,7 @@ test_expect_success 'diff -U0' '
        do
                git diff -U0 file-?$n
        done | zc >actual &&
-       diff -u expect actual
+       test_cmp expect actual
 
 '