[PATCH v1] preload-index: update GIT_FORCE_PRELOAD_TEST support

[Ben Peart]

Rename GIT_FORCE_PRELOAD_TEST to GIT_TEST_PRELOAD for consistency with the
other GIT_TEST_ special setups and properly document its use.

Signed-off-by: Ben Peart <ben.pe...@microsoft.com>
---

Notes:
    Base Ref: v2.19.0
    Web-Diff: https://github.com/benpeart/git/commit/dcd201b920
    Checkout: git fetch https://github.com/benpeart/git git-test-preload-v1 && 
git checkout dcd201b920

 preload-index.c             | 2 +-
 t/README                    | 3 +++
 t/t7519-status-fsmonitor.sh | 4 ++--
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/preload-index.c b/preload-index.c
index 71cd2437a3..cc8a7333c2 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -84,7 +84,7 @@ static void preload_index(struct index_state *index,
                return;
 
        threads = index->cache_nr / THREAD_COST;
-       if ((index->cache_nr > 1) && (threads < 2) && 
getenv("GIT_FORCE_PRELOAD_TEST"))
+       if ((index->cache_nr > 1) && (threads < 2) && 
git_env_bool("GIT_TEST_PRELOAD", 0))
                threads = 2;
        if (threads < 2)
                return;
diff --git a/t/README b/t/README
index 9028b47d92..73fb09560f 100644
--- a/t/README
+++ b/t/README
@@ -319,6 +319,9 @@ GIT_TEST_OE_DELTA_SIZE=<n> exercises the uncomon 
pack-objects code
 path where deltas larger than this limit require extra memory
 allocation for bookkeeping.
 
+GIT_TEST_PRELOAD=<boolean> exercises the preload-index code path by
+overriding the minimum number of cache entries required per thread.
+
 Naming Tests
 ------------
 
diff --git a/t/t7519-status-fsmonitor.sh b/t/t7519-status-fsmonitor.sh
index 756beb0d8e..9b703d49b5 100755
--- a/t/t7519-status-fsmonitor.sh
+++ b/t/t7519-status-fsmonitor.sh
@@ -245,9 +245,9 @@ do
                git config core.preloadIndex $preload_val &&
                if test $preload_val = true
                then
-                       GIT_FORCE_PRELOAD_TEST=$preload_val; export 
GIT_FORCE_PRELOAD_TEST
+                       GIT_TEST_PRELOAD=$preload_val; export GIT_TEST_PRELOAD
                else
-                       unset GIT_FORCE_PRELOAD_TEST
+                       sane_unset GIT_TEST_PRELOAD
                fi
        '
 

base-commit: 1d4361b0f344188ab5eec6dcea01f61a3a3a1670
-- 
2.18.0.windows.1