sparse-checkout: list directories in cone mode

When core.sparseCheckoutCone is enabled, the 'git sparse-checkout set'
command takes a list of directories as input, then creates an ordered
list of sparse-checkout patterns such that those directories are
recursively included and all sibling entries along the parent directories
are also included. Listing the patterns is less user-friendly than the
directories themselves.

In cone mode, and as long as the patterns match the expected cone-mode
pattern types, change the output of 'git sparse-checkout list' to only
show the directories that created the patterns.

With this change, the following piped commands would not change the
working directory:

	git sparse-checkout list | git sparse-checkout set --stdin

The only time this would not work is if core.sparseCheckoutCone is
true, but the sparse-checkout file contains patterns that do not
match the expected pattern types for cone mode.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 5d62f7a66d..b3bed891cb 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -53,6 +53,8 @@ static int sparse_checkout_list(int argc, const char **argv)
 
 	memset(&pl, 0, sizeof(pl));
 
+	pl.use_cone_patterns = core_sparse_checkout_cone;
+
 	sparse_filename = get_sparse_checkout_filename();
 	res = add_patterns_from_file_to_list(sparse_filename, "", 0, &pl, NULL);
 	free(sparse_filename);
@@ -62,6 +64,25 @@ static int sparse_checkout_list(int argc, const char **argv)
 		return 0;
 	}
 
+	if (pl.use_cone_patterns) {
+		int i;
+		struct pattern_entry *pe;
+		struct hashmap_iter iter;
+		struct string_list sl = STRING_LIST_INIT_DUP;
+
+		hashmap_for_each_entry(&pl.recursive_hashmap, &iter, pe, ent) {
+			/* pe->pattern starts with "/", skip it */
+			string_list_insert(&sl, pe->pattern + 1);
+		}
+
+		string_list_sort(&sl);
+
+		for (i = 0; i < sl.nr; i++)
+			printf("%s\n", sl.items[i].string);
+
+		return 0;
+	}
+
 	write_patterns_to_file(stdout, &pl);
 	clear_pattern_list(&pl);