sparse-checkout: use new update_sparsity() function

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.

Note that when an issue is hit, the error message splits 'error' and
'Cannot update sparse checkout' on separate lines.  For now, we use two
greps to find both pieces of the error message but subsequent commits
will clean up the messages reported to the user.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/sparse-checkout.c

@@ -94,49 +94,35 @@ static int sparse_checkout_list(int argc, const char **argv)
 
 static int update_working_directory(struct pattern_list *pl)
 {
-	int result = 0;
+	enum update_sparsity_result result;
 	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;
 	o.head_idx = -1;
 	o.src_index = r->index;
 	o.dst_index = r->index;
 	o.skip_sparse_checkout = 0;
 	o.pl = pl;
 
-	resolve_undo_clear_index(r->index);
 	setup_work_tree();
 
-	cache_tree_free(&r->index->cache_tree);
-
 	repo_hold_locked_index(r, &lock_file, LOCK_DIE_ON_ERROR);
 
-	core_apply_sparse_checkout = 1;
-	result = unpack_trees(1, &t, &o);
+	result = update_sparsity(&o);
 
-	if (!result) {
-		prime_cache_tree(r, r->index, tree);
+	if (result == UPDATE_SPARSITY_WARNINGS)
+		/*
+		 * We don't do any special handling of warnings from untracked
+		 * files in the way or dirty entries that can't be removed.
+		 */
+		result = UPDATE_SPARSITY_SUCCESS;
+	if (result == UPDATE_SPARSITY_SUCCESS)
 		write_locked_index(r->index, &lock_file, COMMIT_LOCK);
-	} else
+	else
 		rollback_lock_file(&lock_file);
 
 	return result;
@@ -303,8 +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,
@@ -559,8 +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,
@@ -576,8 +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);

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' '
@@ -316,16 +323,28 @@ 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 "error" err &&
+	test_i18ngrep "Cannot update sparse checkout" err &&
+
+	git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* 2>err &&
+	test_i18ngrep "error" err &&
+	test_i18ngrep "Cannot update sparse checkout" err &&
+	test_path_is_file dirty/folder1/a &&
+
+	git -C dirty sparse-checkout disable 2>err &&
+	test_must_be_empty err &&
+
 	git -C dirty reset --hard &&
 	git -C dirty sparse-checkout init &&
 	git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* &&
-	git -C dirty sparse-checkout disable
+	test_path_is_missing dirty/folder1/a &&
+	git -C dirty sparse-checkout disable &&
+	test_path_is_file dirty/folder1/a
 '
 
 test_expect_success 'cone mode: set with core.ignoreCase=true' '