Merge pull request microsoft#426 from vdye/sparse-index/read-tree

Sparse index: integrate with `read-tree`

builtin/read-tree.c

@@ -160,15 +160,18 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
 			     read_tree_usage, 0);
 
-	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
-
 	prefix_set = opts.prefix ? 1 : 0;
 	if (1 < opts.merge + opts.reset + prefix_set)
 		die("Which one? -m, --reset, or --prefix?");
 
 	if (opts.reset)
 		opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
 
+	prepare_repo_settings(the_repository);
+	the_repository->settings.command_requires_full_index = 0;
+
+	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
+
 	/*
 	 * NEEDSWORK
 	 *
@@ -210,6 +213,9 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	if (opts.merge && !opts.index_only)
 		setup_work_tree();
 
+	if (opts.skip_sparse_checkout)
+		ensure_full_index(&the_index);
+
 	if (opts.merge) {
 		switch (stage - 1) {
 		case 0:
@@ -219,11 +225,21 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 			opts.fn = opts.prefix ? bind_merge : oneway_merge;
 			break;
 		case 2:
+			/*
+			 * TODO: update twoway_merge to handle edit/edit conflicts in
+			 * sparse directories.
+			 */
+			ensure_full_index(&the_index);
 			opts.fn = twoway_merge;
 			opts.initial_checkout = is_cache_unborn();
 			break;
 		case 3:
 		default:
+			/*
+			 * TODO: update threeway_merge to handle edit/edit conflicts in
+			 * sparse directories.
+			 */
+			ensure_full_index(&the_index);
 			opts.fn = threeway_merge;
 			break;
 		}

t/perf/p2000-sparse-operations.sh

@@ -113,6 +113,7 @@ test_perf_on_all git checkout -f -
 test_perf_on_all git reset
 test_perf_on_all git reset --hard
 test_perf_on_all git reset -- does-not-exist
+test_perf_on_all git read-tree -mu HEAD
 test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove
 test_perf_on_all git diff

t/t1092-sparse-checkout-compatibility.sh

@@ -817,6 +817,117 @@ test_expect_success 'update-index --cacheinfo' '
 	test_sparse_match git status --porcelain=v2
 '
 
+test_expect_success 'read-tree --merge with files outside sparse definition' '
+	init_repos &&
+
+	test_all_match git checkout -b test-branch update-folder1 &&
+	for MERGE_TREES in "base HEAD update-folder2" \
+			   "update-folder1 update-folder2" \
+			   "update-folder2"
+	do
+		# Clean up and remove on-disk files
+		test_all_match git reset --hard HEAD &&
+		test_sparse_match git sparse-checkout reapply &&
+
+		# Although the index matches, without --no-sparse-checkout, outside-of-
+		# definition files will not exist on disk for sparse checkouts
+		test_all_match git read-tree -mu $MERGE_TREES &&
+		test_all_match git status --porcelain=v2 &&
+		test_path_is_missing sparse-checkout/folder2 &&
+		test_path_is_missing sparse-index/folder2 &&
+
+		test_all_match git read-tree --reset -u HEAD &&
+		test_all_match git status --porcelain=v2 &&
+
+		test_all_match git read-tree -mu --no-sparse-checkout $MERGE_TREES &&
+		test_all_match git status --porcelain=v2 &&
+		test_cmp sparse-checkout/folder2/a sparse-index/folder2/a &&
+		test_cmp sparse-checkout/folder2/a full-checkout/folder2/a || return 1
+	done
+'
+
+test_expect_success 'read-tree --merge with edit/edit conflicts in sparse directories' '
+	init_repos &&
+
+	# Merge of multiple changes to same directory (but not same files) should
+	# succeed
+	test_all_match git read-tree -mu base rename-base update-folder1 &&
+	test_all_match git status --porcelain=v2 &&
+
+	test_all_match git reset --hard &&
+
+	test_all_match git read-tree -mu rename-base update-folder2 &&
+	test_all_match git status --porcelain=v2 &&
+
+	test_all_match git reset --hard &&
+
+	test_all_match test_must_fail git read-tree -mu base update-folder1 rename-out-to-in &&
+	test_all_match test_must_fail git read-tree -mu rename-out-to-in update-folder1
+'
+
+test_expect_success 'read-tree --merge with modified file outside definition' '
+	init_repos &&
+
+	write_script edit-contents <<-\EOF &&
+	echo text >>$1
+	EOF
+
+	test_all_match git checkout -b test-branch update-folder1 &&
+	run_on_sparse mkdir -p folder2 &&
+	run_on_all ../edit-contents folder2/a &&
+
+	# With manually-modified file, full-checkout cannot merge, but it is ignored
+	# in sparse checkouts
+	test_must_fail git -C full-checkout read-tree -mu update-folder2 &&
+	test_sparse_match git read-tree -mu update-folder2 &&
+	test_sparse_match git status --porcelain=v2 &&
+
+	# Reset only the sparse checkouts to "undo" the merge. All three checkouts
+	# now have matching indexes and matching folder2/a on disk.
+	test_sparse_match git read-tree --reset -u HEAD &&
+
+	# When --no-sparse-checkout is specified, sparse checkouts identify the file
+	# on disk and prevent the merge
+	test_all_match test_must_fail git read-tree -mu --no-sparse-checkout update-folder2
+'
+
+test_expect_success 'read-tree --prefix outside sparse definition' '
+	init_repos &&
+
+	# Cannot read-tree --prefix with a single argument when files exist within
+	# prefix
+	test_all_match test_must_fail git read-tree --prefix=folder1/ -u update-folder1 &&
+
+	test_all_match git read-tree --prefix=folder2/0 -u rename-base &&
+	test_path_is_missing sparse-checkout/folder2 &&
+	test_path_is_missing sparse-index/folder2 &&
+
+	test_all_match git read-tree --reset -u HEAD &&
+	test_all_match git read-tree --prefix=folder2/0 -u --no-sparse-checkout rename-base &&
+	test_cmp sparse-checkout/folder2/0/a sparse-index/folder2/0/a &&
+	test_cmp sparse-checkout/folder2/0/a full-checkout/folder2/0/a
+'
+
+test_expect_success 'read-tree --merge with directory-file conflicts' '
+	init_repos &&
+
+	test_all_match git checkout -b test-branch rename-base &&
+
+	# Although the index matches, without --no-sparse-checkout, outside-of-
+	# definition files will not exist on disk for sparse checkouts
+	test_sparse_match git read-tree -mu rename-out-to-out &&
+	test_sparse_match git status --porcelain=v2 &&
+	test_path_is_missing sparse-checkout/folder2 &&
+	test_path_is_missing sparse-index/folder2 &&
+
+	test_sparse_match git read-tree --reset -u HEAD &&
+	test_sparse_match git status --porcelain=v2 &&
+
+	test_sparse_match git read-tree -mu --no-sparse-checkout rename-out-to-out &&
+	test_sparse_match git status --porcelain=v2 &&
+	test_cmp sparse-checkout/folder2/0/1 sparse-index/folder2/0/1
+'
+
 test_expect_success 'merge, cherry-pick, and rebase' '
 	init_repos &&
 
@@ -1395,6 +1506,23 @@ test_expect_success 'sparse index is not expanded: update-index' '
 	ensure_not_expanded update-index --add --remove --again
 '
 
+test_expect_success 'sparse index is not expanded: read-tree' '
+	init_repos &&
+
+	ensure_not_expanded checkout -b test-branch update-folder1 &&
+	for MERGE_TREES in "update-folder2"
+	do
+		ensure_not_expanded read-tree -mu $MERGE_TREES &&
+		ensure_not_expanded reset --hard HEAD || return 1
+	done &&
+
+	rm -rf sparse-index/deep/deeper2 &&
+	ensure_not_expanded add . &&
+	ensure_not_expanded commit -m "test" &&
+
+	ensure_not_expanded read-tree --prefix=deep/deeper2 -u deepest
+'
+
 # NEEDSWORK: a sparse-checkout behaves differently from a full checkout
 # in this scenario, but it shouldn't.
 test_expect_success 'reset mixed and checkout orphan' '

unpack-trees.c

@@ -1772,6 +1772,58 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 		setup_standard_excludes(o->dir);
 	}
 
+	/*
+	 * If the prefix is equal to or contained within a sparse directory, the
+	 * index needs to be expanded to traverse with the specified prefix. Note
+	 * that only the src_index is checked because the prefix is only specified
+	 * in cases where src_index == dst_index.
+	 */
+	if (o->prefix && o->src_index->sparse_index) {
+		int i, ce_len;
+		struct cache_entry *ce;
+		int prefix_len = strlen(o->prefix);
+
+		if (prefix_len > 0) {
+			for (i = 0; i < o->src_index->cache_nr; i++) {
+				ce = o->src_index->cache[i];
+				ce_len = ce_namelen(ce);
+
+				if (!S_ISSPARSEDIR(ce->ce_mode))
+					continue;
+
+				/*
+				 * Normalize comparison length for cache entry vs. prefix -
+				 * either may have a trailing slash, which we do not want to
+				 * compare (can assume both are directories).
+				 */
+				if (ce->name[ce_len - 1] == '/')
+					ce_len--;
+				if (o->prefix[prefix_len - 1] == '/')
+					prefix_len--;
+
+				/*
+				 * If prefix length is shorter, then it is either a parent to
+				 * this sparse directory, or a completely different path. In
+				 * either case, we don't need to expand the index
+				 */
+				if (prefix_len < ce_len)
+					continue;
+
+				/*
+				 * Avoid the case of expanding the index with a prefix
+				 * a/beta for a sparse directory a/b.
+				 */
+				if (ce_len < prefix_len && o->prefix[ce_len] != '/')
+					continue;
+
+				if (!strncmp(ce->name, o->prefix, ce_len)) {
+					ensure_full_index(o->src_index);
+					break;
+				}
+			}
+		}
+	}
+
 	if (!core_apply_sparse_checkout || !o->update)
 		o->skip_sparse_checkout = 1;
 	if (!o->skip_sparse_checkout && !o->pl) {

wt-status.c

@@ -651,6 +651,13 @@ static void wt_status_collect_changes_index(struct wt_status *s)
 	rev.diffopt.detect_rename = s->detect_rename >= 0 ? s->detect_rename : rev.diffopt.detect_rename;
 	rev.diffopt.rename_limit = s->rename_limit >= 0 ? s->rename_limit : rev.diffopt.rename_limit;
 	rev.diffopt.rename_score = s->rename_score >= 0 ? s->rename_score : rev.diffopt.rename_score;
+
+	/*
+	 * The `recursive` flag must be set to properly perform a diff on sparse
+	 * directory entries, if they exist
+	 */
+	rev.diffopt.flags.recursive = 1;
+
 	copy_pathspec(&rev.prune_data, &s->pathspec);
 	run_diff_index(&rev, 1);
 	object_array_clear(&rev.pending);