Re: [PATCH 6/7] sparse-checkout: use new update_sparsity() function

From: Elijah Newren <redacted>

Remove the equivalent of 'git read-tree -mu HEAD' in the sparse-checkout
codepaths for setting the SKIP_WORKTREE bits and instead use the new
update_sparsity() function.

Signed-off-by: Elijah Newren <redacted>
---
 builtin/sparse-checkout.c          | 39 +++++++-----------------------
 t/t1091-sparse-checkout-builtin.sh | 32 +++++++++++++++++-------
 2 files changed, 32 insertions(+), 39 deletions(-)

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 740da4b6d54..5d3ec2e6be9 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c

@@ -97,47 +97,32 @@ static int update_working_directory(struct pattern_list *pl)
 	int result = 0;
 	struct unpack_trees_options o;
 	struct lock_file lock_file = LOCK_INIT;
-	struct object_id oid;
-	struct tree *tree;
-	struct tree_desc t;
 	struct repository *r = the_repository;
 
-	if (repo_read_index_unmerged(r))
-		die(_("you need to resolve your current index first"));
-
-	if (get_oid("HEAD", &oid))
-		return 0;
-
-	tree = parse_tree_indirect(&oid);
-	parse_tree(tree);
-	init_tree_desc(&t, tree->buffer, tree->size);
-
 	memset(&o, 0, sizeof(o));
 	o.verbose_update = isatty(2);
-	o.merge = 1;
 	o.update = 1;
-	o.fn = oneway_merge;

+		/*
+		 * We don't do any special handling of warnings from untracked
+		 * files in the way or dirty entries that can't be removed.
+		 */
+		result = 0;
+	if (!result)
 		write_locked_index(r->index, &lock_file, COMMIT_LOCK);
-	} else
+	else
 		rollback_lock_file(&lock_file);
 
 	return result;

@@ -304,8 +289,6 @@ static int sparse_checkout_init(int argc, const char **argv)
 	};
 
 	repo_read_index(the_repository);
-	require_clean_work_tree(the_repository,
-				N_("initialize sparse-checkout"), NULL, 1, 0);
 
 	argc = parse_options(argc, argv, NULL,
 			     builtin_sparse_checkout_init_options,

@@ -560,8 +543,6 @@ static int sparse_checkout_set(int argc, const char **argv, const char *prefix,
 	};
 
 	repo_read_index(the_repository);
-	require_clean_work_tree(the_repository,
-				N_("set sparse-checkout patterns"), NULL, 1, 0);
 
 	argc = parse_options(argc, argv, prefix,
 			     builtin_sparse_checkout_set_options,

@@ -577,8 +558,6 @@ static int sparse_checkout_disable(int argc, const char **argv)
 	struct strbuf match_all = STRBUF_INIT;
 
 	repo_read_index(the_repository);
-	require_clean_work_tree(the_repository,
-				N_("disable sparse-checkout"), NULL, 1, 0);

 	memset(&pl, 0, sizeof(pl));
 	hashmap_init(&pl.recursive_hashmap, pl_hashmap_cmp, NULL, 0);

diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index 8607a8e6d1a..0d93d3983e0 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh

@@ -277,16 +277,23 @@ test_expect_success 'cone mode: add parent path' '
 	check_files repo a deep folder1
 '
 
-test_expect_success 'revert to old sparse-checkout on bad update' '
+test_expect_success 'not-up-to-date does not block rest of sparsification' '
 	test_when_finished git -C repo sparse-checkout disable &&
 	test_when_finished git -C repo reset --hard &&
 	git -C repo sparse-checkout set deep &&
+
 	echo update >repo/deep/deeper2/a &&
 	cp repo/.git/info/sparse-checkout expect &&
-	test_must_fail git -C repo sparse-checkout set deep/deeper1 2>err &&
-	test_i18ngrep "cannot set sparse-checkout patterns" err &&
-	test_cmp repo/.git/info/sparse-checkout expect &&
-	check_files repo/deep a deeper1 deeper2
+	test_write_lines "!/deep/*/" "/deep/deeper1/" >>expect &&
+
+	git -C repo sparse-checkout set deep/deeper1 2>err &&
+
+	test_i18ngrep "Cannot update sparse checkout" err &&
+	test_cmp expect repo/.git/info/sparse-checkout &&
+	check_files repo/deep a deeper1 deeper2 &&
+	check_files repo/deep/deeper1 a deepest &&
+	check_files repo/deep/deeper1/deepest a &&
+	check_files repo/deep/deeper2 a
 '
 
 test_expect_success 'revert to old sparse-checkout on empty update' '

@@ -316,12 +323,19 @@ test_expect_success '.gitignore should not warn about cone mode' '
 	test_i18ngrep ! "disabling cone patterns" err
 '
 
-test_expect_success 'sparse-checkout (init|set|disable) fails with dirty status' '
+test_expect_success 'sparse-checkout (init|set|disable) warns with dirty status' '
 	git clone repo dirty &&
 	echo dirty >dirty/folder1/a &&
-	test_must_fail git -C dirty sparse-checkout init &&
-	test_must_fail git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* &&
-	test_must_fail git -C dirty sparse-checkout disable &&
+
+	git -C dirty sparse-checkout init 2>err &&
+	test_i18ngrep "warning.*Cannot update sparse checkout" err &&
+
+	git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* &&
+	test_i18ngrep "warning.*Cannot update sparse checkout" err &&
+
+	git -C dirty sparse-checkout disable &&
+	test_i18ngrep "warning.*Cannot update sparse checkout" err &&
+
 	git -C dirty reset --hard &&
 	git -C dirty sparse-checkout init &&
 	git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* &&