8 files changed, 168 insertions, 82 deletions

diff --git a/Documentation/git-ls-files.txt b/Documentation/git-ls-files.txt
index 2e3d695..48cc7c0 100644
--- a/Documentation/git-ls-files.txt
+++ b/Documentation/git-ls-files.txt
@@ -187,6 +187,11 @@ Both the <eolinfo> in the index ("i/<eolinfo>")
 and in the working tree ("w/<eolinfo>") are shown for regular files,
 followed by the  ("attr/<eolattr>").
 
+--sparse::
+	If the index is sparse, show the sparse directories without expanding
+	to the contained files. Sparse directories will be shown with a
+	trailing slash, such as "x/" for a sparse directory "x".
+
 \--::
 	Do not interpret any more arguments as options.
 
diff --git a/builtin/fetch.c b/builtin/fetch.c
index f1fe73a..e33fda4 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -2009,6 +2009,8 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	}
 
 	git_config(git_fetch_config, NULL);
+	prepare_repo_settings(the_repository);
+	the_repository->settings.command_requires_full_index = 0;
 
 	argc = parse_options(argc, argv, prefix,
 			     builtin_fetch_options, builtin_fetch_usage, 0);
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 031fef1..c151eb1 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -37,6 +37,7 @@ static int debug_mode;
 static int show_eol;
 static int recurse_submodules;
 static int skipping_duplicates;
+static int show_sparse_dirs;
 
 static const char *prefix;
 static int max_prefix_len;
@@ -315,8 +316,10 @@ static void show_files(struct repository *repo, struct dir_struct *dir)
 
 	if (!(show_cached || show_stage || show_deleted || show_modified))
 		return;
-	/* TODO: audit for interaction with sparse-index. */
-	ensure_full_index(repo->index);
+
+	if (!show_sparse_dirs)
+		ensure_full_index(repo->index);
+
 	for (i = 0; i < repo->index->cache_nr; i++) {
 		const struct cache_entry *ce = repo->index->cache[i];
 		struct stat st;
@@ -670,6 +673,8 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 		OPT_BOOL(0, "debug", &debug_mode, N_("show debugging data")),
 		OPT_BOOL(0, "deduplicate", &skipping_duplicates,
 			 N_("suppress duplicate entries")),
+		OPT_BOOL(0, "sparse", &show_sparse_dirs,
+			 N_("show sparse directories in the presence of a sparse index")),
 		OPT_END()
 	};
 	int ret = 0;
@@ -677,6 +682,9 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage_with_options(ls_files_usage, builtin_ls_files_options);
 
+	prepare_repo_settings(the_repository);
+	the_repository->settings.command_requires_full_index = 0;
+
 	prefix = cmd_prefix;
 	if (prefix)
 		prefix_len = strlen(prefix);
diff --git a/builtin/pull.c b/builtin/pull.c
index c845761..100cbf9 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -994,6 +994,8 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 		set_reflog_message(argc, argv);
 
 	git_config(git_pull_config, NULL);
+	prepare_repo_settings(the_repository);
+	the_repository->settings.command_requires_full_index = 0;
 
 	argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
 
diff --git a/t/helper/test-read-cache.c b/t/helper/test-read-cache.c
index 0d9f089..b736ef1 100644
--- a/t/helper/test-read-cache.c
+++ b/t/helper/test-read-cache.c
@@ -1,83 +1,39 @@
 #include "test-tool.h"
 #include "cache.h"
 #include "config.h"
-#include "blob.h"
-#include "commit.h"
-#include "tree.h"
-#include "sparse-index.h"
-
-static void print_cache_entry(struct cache_entry *ce)
-{
-	const char *type;
-	printf("%06o ", ce->ce_mode & 0177777);
-
-	if (S_ISSPARSEDIR(ce->ce_mode))
-		type = tree_type;
-	else if (S_ISGITLINK(ce->ce_mode))
-		type = commit_type;
-	else
-		type = blob_type;
-
-	printf("%s %s\t%s\n",
-	       type,
-	       oid_to_hex(&ce->oid),
-	       ce->name);
-}
-
-static void print_cache(struct index_state *istate)
-{
-	int i;
-	for (i = 0; i < istate->cache_nr; i++)
-		print_cache_entry(istate->cache[i]);
-}
 
 int cmd__read_cache(int argc, const char **argv)
 {
-	struct repository *r = the_repository;
 	int i, cnt = 1;
 	const char *name = NULL;
-	int table = 0, expand = 0;
 
 	initialize_the_repository();
 
-	for (++argv, --argc; *argv && starts_with(*argv, "--"); ++argv, --argc) {
-		if (skip_prefix(*argv, "--print-and-refresh=", &name))
-			continue;
-		if (!strcmp(*argv, "--table"))
-			table = 1;
-		else if (!strcmp(*argv, "--expand"))
-			expand = 1;
+	if (argc > 1 && skip_prefix(argv[1], "--print-and-refresh=", &name)) {
+		argc--;
+		argv++;
 	}
 
-	if (argc == 1)
-		cnt = strtol(argv[0], NULL, 0);
+	if (argc == 2)
+		cnt = strtol(argv[1], NULL, 0);
 	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);
-
-		if (expand)
-			ensure_full_index(r->index);
-
+		read_cache();
 		if (name) {
 			int pos;
 
-			refresh_index(r->index, REFRESH_QUIET,
+			refresh_index(&the_index, REFRESH_QUIET,
 				      NULL, NULL, NULL);
-			pos = index_name_pos(r->index, name, strlen(name));
+			pos = index_name_pos(&the_index, name, strlen(name));
 			if (pos < 0)
 				die("%s not in index", name);
 			printf("%s is%s up to date\n", name,
-			       ce_uptodate(r->index->cache[pos]) ? "" : " not");
+			       ce_uptodate(the_index.cache[pos]) ? "" : " not");
 			write_file(name, "%d\n", i);
 		}
-		if (table)
-			print_cache(r->index);
-		discard_index(r->index);
+		discard_cache();
 	}
 	return 0;
 }
diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index 32a6328..4277698 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -234,12 +234,27 @@ test_expect_success 'sparse-index enabled and disabled' '
 
 		git -C repo sparse-checkout init --cone --sparse-index &&
 		test_cmp_config -C repo true index.sparse &&
-		test-tool -C repo read-cache --table >cache &&
-		grep " tree " cache &&
-
+		git -C repo ls-files --sparse >sparse &&
 		git -C repo sparse-checkout disable &&
-		test-tool -C repo read-cache --table >cache &&
-		! grep " tree " cache &&
+		git -C repo ls-files --sparse >full &&
+
+		cat >expect <<-\EOF &&
+		@@ -1,4 +1,7 @@
+		 a
+		-deep/
+		-folder1/
+		-folder2/
+		+deep/a
+		+deep/deeper1/a
+		+deep/deeper1/deepest/a
+		+deep/deeper2/a
+		+folder1/a
+		+folder2/a
+		EOF
+
+		diff -u sparse full | tail -n +3 >actual &&
+		test_cmp expect actual &&
+
 		git -C repo config --list >config &&
 		! grep index.sparse config
 	)
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 49f70a6..4ba1617 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -206,45 +206,42 @@ test_sparse_unstaged () {
 test_expect_success 'sparse-index contents' '
 	init_repos &&
 
-	test-tool -C sparse-index read-cache --table >cache &&
+	git -C sparse-index ls-files --sparse --stage >cache &&
 	for dir in folder1 folder2 x
 	do
 		TREE=$(git -C sparse-index rev-parse HEAD:$dir) &&
-		grep "040000 tree $TREE	$dir/" cache \
+		grep "040000 $TREE 0	$dir/" cache \
 			|| return 1
 	done &&
 
 	git -C sparse-index sparse-checkout set folder1 &&
 
-	test-tool -C sparse-index read-cache --table >cache &&
+	git -C sparse-index ls-files --sparse --stage >cache &&
 	for dir in deep folder2 x
 	do
 		TREE=$(git -C sparse-index rev-parse HEAD:$dir) &&
-		grep "040000 tree $TREE	$dir/" cache \
+		grep "040000 $TREE 0	$dir/" cache \
 			|| return 1
 	done &&
 
 	git -C sparse-index sparse-checkout set deep/deeper1 &&
 
-	test-tool -C sparse-index read-cache --table >cache &&
+	git -C sparse-index ls-files --sparse --stage >cache &&
 	for dir in deep/deeper2 folder1 folder2 x
 	do
 		TREE=$(git -C sparse-index rev-parse HEAD:$dir) &&
-		grep "040000 tree $TREE	$dir/" cache \
+		grep "040000 $TREE 0	$dir/" cache \
 			|| return 1
 	done &&
 
-	# Disabling the sparse-index removes tree entries with full ones
+	# Disabling the sparse-index replaces tree entries with full ones
 	git -C sparse-index sparse-checkout init --no-sparse-index &&
-
-	test-tool -C sparse-index read-cache --table >cache &&
-	! grep "040000 tree" cache &&
-	test_sparse_match test-tool read-cache --table
+	test_sparse_match git ls-files --stage --sparse
 '
 
 test_expect_success 'expanded in-memory index matches full index' '
 	init_repos &&
-	test_sparse_match test-tool read-cache --expand --table
+	test_sparse_match git ls-files --stage
 '
 
 test_expect_success 'status with options' '
@@ -801,9 +798,9 @@ test_expect_success 'submodule handling' '
 
 	# having a submodule prevents "modules" from collapse
 	test_sparse_match git sparse-checkout set deep/deeper1 &&
-	test-tool -C sparse-index read-cache --table >cache &&
-	grep "100644 blob .*	modules/a" cache &&
-	grep "160000 commit $(git -C initial-repo rev-parse HEAD)	modules/sub" cache
+	git -C sparse-index ls-files --sparse --stage >cache &&
+	grep "100644 .*	modules/a" cache &&
+	grep "160000 $(git -C initial-repo rev-parse HEAD) 0	modules/sub" cache
 '
 
 # When working with a sparse index, some commands will need to expand the
@@ -816,6 +813,12 @@ test_expect_success 'sparse-index is expanded and converted back' '
 	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" \
 		git -C sparse-index reset -- folder1/a &&
 	test_region index convert_to_sparse trace2.txt &&
+	test_region index ensure_full_index trace2.txt &&
+
+	# ls-files expands on read, but does not write.
+	rm trace2.txt &&
+	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
+		git -C sparse-index ls-files &&
 	test_region index ensure_full_index trace2.txt
 '
 
@@ -871,6 +874,7 @@ test_expect_success 'sparse-index is not expanded' '
 	init_repos &&
 
 	ensure_not_expanded status &&
+	ensure_not_expanded ls-files --sparse &&
 	ensure_not_expanded commit --allow-empty -m empty &&
 	echo >>sparse-index/a &&
 	ensure_not_expanded commit -a -m a &&
@@ -1009,6 +1013,100 @@ test_expect_success 'sparse index is not expanded: blame' '
 	done
 '
 
+test_expect_success 'sparse index is not expanded: fetch/pull' '
+	init_repos &&
+
+	git -C sparse-index remote add full "file://$(pwd)/full-checkout" &&
+	ensure_not_expanded fetch full &&
+	git -C full-checkout commit --allow-empty -m "for pull merge" &&
+	git -C sparse-index commit --allow-empty -m "for pull merge" &&
+	ensure_not_expanded pull full base
+'
+
+test_expect_success 'ls-files' '
+	init_repos &&
+
+	# Use a smaller sparse-checkout for reduced output
+	test_sparse_match git sparse-checkout set &&
+
+	# Behavior agrees by default. Sparse index is expanded.
+	test_all_match git ls-files &&
+
+	# With --sparse, the sparse index data changes behavior.
+	git -C sparse-index ls-files --sparse >actual &&
+
+	cat >expect <<-\EOF &&
+	a
+	deep/
+	e
+	folder1-
+	folder1.x
+	folder1/
+	folder10
+	folder2/
+	g
+	x/
+	z
+	EOF
+
+	test_cmp expect actual &&
+
+	# With --sparse and no sparse index, nothing changes.
+	git -C sparse-checkout ls-files >dense &&
+	git -C sparse-checkout ls-files --sparse >sparse &&
+	test_cmp dense sparse &&
+
+	# Set up a strange condition of having a file edit
+	# outside of the sparse-checkout cone. This is just
+	# to verify that sparse-checkout and sparse-index
+	# behave the same in this case.
+	write_script edit-content <<-\EOF &&
+	mkdir folder1 &&
+	echo content >>folder1/a
+	EOF
+	run_on_sparse ../edit-content &&
+
+	# ls-files does not currently notice modified files whose
+	# cache entries are marked SKIP_WORKTREE. This may change
+	# in the future, but here we test that sparse index does
+	# not accidentally create a change of behavior.
+	test_sparse_match git ls-files --modified &&
+	test_must_be_empty sparse-checkout-out &&
+	test_must_be_empty sparse-index-out &&
+
+	git -C sparse-index ls-files --sparse --modified >sparse-index-out &&
+	test_must_be_empty sparse-index-out &&
+
+	# Add folder1 to the sparse-checkout cone and
+	# check that ls-files shows the expanded files.
+	test_sparse_match git sparse-checkout add folder1 &&
+	test_sparse_match git ls-files --modified &&
+
+	test_all_match git ls-files &&
+	git -C sparse-index ls-files --sparse >actual &&
+
+	cat >expect <<-\EOF &&
+	a
+	deep/
+	e
+	folder1-
+	folder1.x
+	folder1/0/0/0
+	folder1/0/1
+	folder1/a
+	folder10
+	folder2/
+	g
+	x/
+	z
+	EOF
+
+	test_cmp expect actual &&
+
+	# Double-check index expansion is avoided
+	ensure_not_expanded ls-files --sparse
+'
+
 # 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' '
@@ -1024,13 +1122,13 @@ test_expect_success 'reset mixed and checkout orphan' '
 	# the sparse checkouts skip "adding" the other side of
 	# the conflict.
 	test_sparse_match git reset --mixed HEAD~1 &&
-	test_sparse_match test-tool read-cache --table --expand &&
+	test_sparse_match git ls-files --stage &&
 	test_sparse_match git status --porcelain=v2 &&
 
 	# At this point, sparse-checkouts behave differently
 	# from the full-checkout.
 	test_sparse_match git checkout --orphan new-branch &&
-	test_sparse_match test-tool read-cache --table --expand &&
+	test_sparse_match git ls-files --stage &&
 	test_sparse_match git status --porcelain=v2
 '
 
diff --git a/t/t3705-add-sparse-checkout.sh b/t/t3705-add-sparse-checkout.sh
index f3143c9..81f3384 100755
--- a/t/t3705-add-sparse-checkout.sh
+++ b/t/t3705-add-sparse-checkout.sh
@@ -181,13 +181,13 @@ test_expect_success 'git add fails outside of sparse-checkout definition' '
 	# Avoid munging CRLFs to avoid an error message
 	git -c core.autocrlf=input add --sparse sparse_entry 2>stderr &&
 	test_must_be_empty stderr &&
-	test-tool read-cache --table >actual &&
-	grep "^100644 blob.*sparse_entry\$" actual &&
+	git ls-files --stage >actual &&
+	grep "^100644 .*sparse_entry\$" actual &&
 
 	git add --sparse --chmod=+x sparse_entry 2>stderr &&
 	test_must_be_empty stderr &&
-	test-tool read-cache --table >actual &&
-	grep "^100755 blob.*sparse_entry\$" actual &&
+	git ls-files --stage >actual &&
+	grep "^100755 .*sparse_entry\$" actual &&
 
 	git reset &&