repo: add the field layout.shallow

This commit is part of the series that introduces the new subcommand
git-repo-info.

The flag `--is-shallow-repository` from git-rev-parse is used for
retrieving whether the repository is shallow. This way, it is used for
querying repository metadata, fitting in the purpose of git-repo-info.

Then, add a new field `layout.shallow` to the git-repo-info subcommand
containing that information.

Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Justin Tobler <jltobler@gmail.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Lucas Seiki Oshiro <lucasseikioshiro@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: lucasoshiro

Documentation/git-repo.adoc

@@ -41,6 +41,9 @@ values that they return:
 `layout.bare`::
 	`true` if this is a bare repository, otherwise `false`.
 
+`layout.shallow`::
+	`true` if this is a shallow repository, otherwise `false`.
+
 `references.format`::
 	The reference storage format. The valid values are:
 +

builtin/repo.c

@@ -6,6 +6,7 @@
 #include "quote.h"
 #include "refs.h"
 #include "strbuf.h"
+#include "shallow.h"
 
 static const char *const repo_usage[] = {
 	"git repo info [<key>...]",
@@ -25,6 +26,13 @@ static int get_layout_bare(struct repository *repo UNUSED, struct strbuf *buf)
 	return 0;
 }
 
+static int get_layout_shallow(struct repository *repo, struct strbuf *buf)
+{
+	strbuf_addstr(buf,
+		      is_repository_shallow(repo) ? "true" : "false");
+	return 0;
+}
+
 static int get_references_format(struct repository *repo, struct strbuf *buf)
 {
 	strbuf_addstr(buf,
@@ -35,6 +43,7 @@ static int get_references_format(struct repository *repo, struct strbuf *buf)
 /* repo_info_fields keys must be in lexicographical order */
 static const struct field repo_info_fields[] = {
 	{ "layout.bare", get_layout_bare },
+	{ "layout.shallow", get_layout_shallow },
 	{ "references.format", get_references_format },
 };
 

t/t1900-repo.sh

@@ -44,6 +44,19 @@ test_repo_info 'bare repository = false is retrieved correctly' \
 test_repo_info 'bare repository = true is retrieved correctly' \
 	'git init --bare' 'bare' 'layout.bare' 'true'
 
+test_repo_info 'shallow repository = false is retrieved correctly' \
+	'git init' 'nonshallow' 'layout.shallow' 'false'
+
+test_expect_success 'setup remote' '
+	git init remote &&
+	echo x >remote/x &&
+	git -C remote add x &&
+	git -C remote commit -m x
+'
+
+test_repo_info 'shallow repository = true is retrieved correctly' \
+	'git clone --depth 1 "file://$PWD/remote"' 'shallow' 'layout.shallow' 'true'
+
 test_expect_success 'values returned in order requested' '
 	cat >expect <<-\EOF &&
 	layout.bare=false