pack-objects: create GIT_TEST_PACK_SPARSE

diff --git a/t/README b/t/README
index 28711cc508f9e5dfb2f2ef238be14926d56f9a12..8b6dfe1864d2307560c8785aac6cace8addafb91 100644 (file)
--- a/t/README
+++ b/t/README
@@ -342,6 +342,10 @@ GIT_TEST_INDEX_VERSION=<n> exercises the index read/write code path
 for the index version specified.  Can be set to any valid version
 (currently 2, 3, or 4).
 
+GIT_TEST_PACK_SPARSE=<boolean> if enabled will default the pack-objects
+builtin to use the sparse object walk. This can still be overridden by
+the --no-sparse command-line argument.
+
 GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
 by overriding the minimum number of cache entries required per thread.