Merge branch 'vd/sparse-sparsity-fix-on-read'

Ensure that the sparseness of the in-core index matches the
index.sparse configuration specified by the repository immediately
after the on-disk index file is read.

* vd/sparse-sparsity-fix-on-read:
  sparse-index: update do_read_index to ensure correct sparsity
  sparse-index: add ensure_correct_sparsity function
  sparse-index: avoid unnecessary cache tree clearing
  test-read-cache.c: prepare_repo_settings after config init

2 files changed, 34 insertions, 2 deletions

diff --git a/t/helper/test-read-cache.c b/t/helper/test-read-cache.c
index b52c174acc..0d9f08931a 100644
--- a/t/helper/test-read-cache.c
+++ b/t/helper/test-read-cache.c
@@ -39,8 +39,6 @@ int cmd__read_cache(int argc, const char **argv)
 	int table = 0, expand = 0;
 
 	initialize_the_repository();
-	prepare_repo_settings(r);
-	r->settings.command_requires_full_index = 0;
 
 	for (++argv, --argc; *argv && starts_with(*argv, "--"); ++argv, --argc) {
 		if (skip_prefix(*argv, "--print-and-refresh=", &name))
@@ -56,6 +54,9 @@ int cmd__read_cache(int argc, const char **argv)
 	setup_git_directory();
 	git_config(git_default_config, NULL);
 
+	prepare_repo_settings(r);
+	r->settings.command_requires_full_index = 0;
+
 	for (i = 0; i < cnt; i++) {
 		repo_read_index(r);
 
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 16fbd2c6db..4eaac6a99b 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -694,6 +694,37 @@ test_expect_success 'sparse-index is expanded and converted back' '
 	test_region index ensure_full_index trace2.txt
 '
 
+test_expect_success 'index.sparse disabled inline uses full index' '
+	init_repos &&
+
+	# When index.sparse is disabled inline with `git status`, the
+	# index is expanded at the beginning of the execution then never
+	# converted back to sparse. It is then written to disk as a full index.
+	rm -f trace2.txt &&
+	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
+		git -C sparse-index -c index.sparse=false status &&
+	! test_region index convert_to_sparse trace2.txt &&
+	test_region index ensure_full_index trace2.txt &&
+
+	# Since index.sparse is set to true at a repo level, the index
+	# is converted from full to sparse when read, then never expanded
+	# over the course of `git status`. It is written to disk as a sparse
+	# index.
+	rm -f trace2.txt &&
+	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
+		git -C sparse-index status &&
+	test_region index convert_to_sparse trace2.txt &&
+	! test_region index ensure_full_index trace2.txt &&
+
+	# Now that the index has been written to disk as sparse, it is not
+	# converted to sparse (or expanded to full) when read by `git status`.
+	rm -f trace2.txt &&
+	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
+		git -C sparse-index status &&
+	! test_region index convert_to_sparse trace2.txt &&
+	! test_region index ensure_full_index trace2.txt
+'
+
 ensure_not_expanded () {
 	rm -f trace2.txt &&
 	echo >>sparse-index/untracked.txt &&