[RFC/PATCH] ls-remote: optionally return non-zero on non-existing refs

[Michael Schubert <mschub@elegosoft.com>]

git ls-remote returns zero no matter if the given references were found
or not. Teach ls-remote an option --exit-status to make it optionally
returning a non-zero status.

Signed-off-by: Michael Schubert <mschub@elegosoft.com>
---

If there is just one existing ref in a list of non-exising refs, this will
return zero though - as "git show-ref" does.


 Documentation/git-ls-remote.txt |    7 ++++++-
 builtin/ls-remote.c             |   12 ++++++++++--
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-ls-remote.txt b/Documentation/git-ls-remote.txt
index c3df8c0..26cf705 100644
--- a/Documentation/git-ls-remote.txt
+++ b/Documentation/git-ls-remote.txt
@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git ls-remote' [--heads] [--tags]  [-u <exec> | --upload-pack <exec>]
-	      <repository> [<refs>...]
+	      [-e|--exit-code] <repository> [<refs>...]
 
 DESCRIPTION
 -----------
@@ -36,6 +36,11 @@ OPTIONS
 	SSH and where the SSH daemon does not use the PATH configured by the
 	user.
 
+-e::
+--exit-code::
+	Exit with a non-zero status code when the specified references don't
+	exist.
+
 <repository>::
 	Location of the repository.  The shorthand defined in
 	$GIT_DIR/branches/ can be used. Use "." (dot) to list references in
diff --git a/builtin/ls-remote.c b/builtin/ls-remote.c
index 1a1ff87..99fcf6b 100644
--- a/builtin/ls-remote.c
+++ b/builtin/ls-remote.c
@@ -5,7 +5,7 @@
 
 static const char ls_remote_usage[] =
 "git ls-remote [--heads] [--tags]  [-u <exec> | --upload-pack <exec>]\n"
-"                     [-q|--quiet] [<repository> [<refs>...]]";
+"                     [-q|--quiet] [-e|--exit-code] [<repository> [<refs>...]]";
 
 /*
  * Is there one among the list of patterns that match the tail part
@@ -35,6 +35,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	unsigned flags = 0;
 	int get_url = 0;
 	int quiet = 0;
+	int exit_code = 0;
 	const char *uploadpack = NULL;
 	const char **pattern = NULL;
 
@@ -74,6 +75,10 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 				get_url = 1;
 				continue;
 			}
+			if (!strcmp("--exit-code", arg) || !strcmp("-e", arg)) {
+				exit_code = 1;
+				continue;
+			}
 			usage(ls_remote_usage);
 		}
 		dest = arg;
@@ -115,12 +120,15 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 
 	if (!dest && !quiet)
 		fprintf(stderr, "From %s\n", *remote->url);
+
 	for ( ; ref; ref = ref->next) {
 		if (!check_ref_type(ref, flags))
 			continue;
 		if (!tail_match(pattern, ref->name))
 			continue;
 		printf("%s	%s\n", sha1_to_hex(ref->old_sha1), ref->name);
+		exit_code = 0;
 	}
-	return 0;
+
+	return (exit_code) ? 2 : 0;
 }
-- 
1.7.5.1