[PATCH] rev-parse: rev-parse: add --is-shallow-repository

Running `git fetch --unshallow` on a repo that is not in fact shallow
produces a fatal error message. Add a helper to rev-parse that scripters
can use to determine whether a repo is shallow or not.

Signed-off-by: Øystein Walle <redacted>
---
 Documentation/git-rev-parse.txt |  3 +++
 builtin/rev-parse.c             |  5 +++++
 t/t1500-rev-parse.sh            | 15 +++++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index b1293f24b..0917b8207 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt

@@ -235,6 +235,9 @@ print a message to stderr and exit with nonzero status.
 --is-bare-repository::
 	When the repository is bare print "true", otherwise "false".
 
+--is-shallow-repository::
+	When the repository is shallow print "true", otherwise "false".
+
 --resolve-git-dir <path>::
 	Check if <path> is a valid repository or a gitfile that
 	points at a valid repository, and print the location of the

diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 2bd28d3c0..c923207f2 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c

@@ -868,6 +868,11 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 						: "false");
 				continue;
 			}
+			if (!strcmp(arg, "--is-shallow-repository")) {
+				printf("%s\n", is_repository_shallow() ? "true"
+						: "false");
+				continue;
+			}
 			if (!strcmp(arg, "--shared-index-path")) {
 				if (read_cache() < 0)
 					die(_("Could not read the index"));

diff --git a/t/t1500-rev-parse.sh b/t/t1500-rev-parse.sh
index 03d3c7f6d..9d3433a30 100755
--- a/t/t1500-rev-parse.sh
+++ b/t/t1500-rev-parse.sh

@@ -116,6 +116,21 @@ test_expect_success 'git-path inside sub-dir' '
 	test_cmp expect actual
 '
 
+test_expect_success 'git-path shallow repository' '
+	test_commit test_commit &&
+	echo true >expect &&
+	git clone --depth 1 --no-local . shallow &&
+	test_when_finished "rm -rf shallow" &&
+	git -C shallow rev-parse --is-shallow-repository >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git-path notshallow repository' '
+	echo false >expect &&
+	git rev-parse --is-shallow-repository >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'showing the superproject correctly' '
 	git rev-parse --show-superproject-working-tree >out &&
 	test_must_be_empty out &&

-- 
2.11.0.485.g4e59582

Hi,

Øystein Walle wrote:

Running `git fetch --unshallow` on a repo that is not in fact shallow
produces a fatal error message.

Hm, can you say more about the context?  From a certain point of view,
it might make sense for that command to succeed instead: if the repo
is already unshallow, then why should't "fetch --unshallow" complain
instead of declaring victory?

                                Add a helper to rev-parse that scripters
can use to determine whether a repo is shallow or not.

Signed-off-by: Øystein Walle <redacted>
---
 Documentation/git-rev-parse.txt |  3 +++
 builtin/rev-parse.c             |  5 +++++
 t/t1500-rev-parse.sh            | 15 +++++++++++++++
 3 files changed, 23 insertions(+)

Regardless, this new rev-parse --is-shallow helper looks like a good
feature.

[...]

The implementation is straightforward and correct.

[...]

Thanks for writing tests. \o/

What does git-path mean here?  I wonder if it's a copy/paste error.
Did you mean something like

 test_expect_success 'rev-parse --is-shallow-repository in shallow repo' '

?

+	test_commit test_commit &&
+	echo true >expect &&
+	git clone --depth 1 --no-local . shallow &&
+	test_when_finished "rm -rf shallow" &&
+	git -C shallow rev-parse --is-shallow-repository >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git-path notshallow repository' '

Likewise: should this be

 test_expect_success 'rev-parse --is-shallow-repository in non-shallow repo' '

?

+	echo false >expect &&
+	git rev-parse --is-shallow-repository >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'showing the superproject correctly' '

With the two tweaks mentioned above,
Reviewed-by: Jonathan Nieder <redacted>

Thanks.