pack-objects: document about thread synchronization

diff --git a/t/t1512-rev-parse-disambiguation.sh b/t/t1512-rev-parse-disambiguation.sh
index 270146204140bf32a12a9664817d32615cc11752..96fe3754c8c96fd65286d4eea44cb65b0edde343 100755 (executable)
--- a/t/t1512-rev-parse-disambiguation.sh
+++ b/t/t1512-rev-parse-disambiguation.sh
@@ -22,6 +22,12 @@ one tagged as v1.0.0.  They all have one regular file each.
 
 . ./test-lib.sh
 
+if ! test_have_prereq SHA1
+then
+       skip_all='not using SHA-1 for objects'
+       test_done
+fi
+
 test_expect_success 'blob and tree' '
        test_tick &&
        (