[PATCH 3/3] Make old sha1 optional with git update-ref -d

["Karl Hasselström" <kha@treskal.com>]

Giving the old sha1 is already optional when changing a ref, and it's
quite handy when running update-ref manually. So make it optional for
deleting a ref too.

Signed-off-by: Karl Hasselström <kha@treskal.com>

---

 Documentation/git-update-ref.txt |    2 +-
 builtin-update-ref.c             |    8 ++++----
 t/t1400-update-ref.sh            |    8 ++++++++
 3 files changed, 13 insertions(+), 5 deletions(-)


diff --git a/Documentation/git-update-ref.txt b/Documentation/git-update-ref.txt
index 4dc4759..80b94c3 100644
--- a/Documentation/git-update-ref.txt
+++ b/Documentation/git-update-ref.txt
@@ -7,7 +7,7 @@ git-update-ref - Update the object name stored in a ref safely
 
 SYNOPSIS
 --------
-'git-update-ref' [-m <reason>] (-d <ref> <oldvalue> | [--no-deref] <ref> <newvalue> [<oldvalue>])
+'git-update-ref' [-m <reason>] (-d <ref> [<oldvalue>] | [--no-deref] <ref> <newvalue> [<oldvalue>])
 
 DESCRIPTION
 -----------
diff --git a/builtin-update-ref.c b/builtin-update-ref.c
index 0d3eb8e..054e64d 100644
--- a/builtin-update-ref.c
+++ b/builtin-update-ref.c
@@ -4,7 +4,7 @@
 #include "parse-options.h"
 
 static const char * const git_update_ref_usage[] = {
-	"git-update-ref [options] -d <refname> <oldval>",
+	"git-update-ref [options] -d <refname> [<oldval>]",
 	"git-update-ref [options]    <refname> <newval> [<oldval>]",
 	NULL
 };
@@ -28,11 +28,11 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 		die("Refusing to perform update with empty message.");
 
 	if (delete) {
-		if (argc != 2)
+		if (argc < 1 || argc > 2)
 			usage_with_options(git_update_ref_usage, options);
 		refname = argv[0];
 		value = NULL;
-		oldval = argv[1];
+		oldval = argc > 1 ? argv[1] : NULL;
 	} else {
 		if (argc < 2 || argc > 3)
 			usage_with_options(git_update_ref_usage, options);
@@ -48,7 +48,7 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 		die("%s: not a valid old SHA1", oldval);
 
 	if (delete)
-		return delete_ref(refname, oldsha1);
+		return delete_ref(refname, oldval ? oldsha1 : NULL);
 	else
 		return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
 				  no_deref ? REF_NODEREF : 0, DIE_ON_ERR);
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index b88e767..da82645 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -42,6 +42,14 @@ test_expect_success "delete $m" "
 "
 rm -f .git/$m
 
+test_expect_success "delete $m without oldvalue verification" "
+	git update-ref $m $A &&
+	test $A = \$(cat .git/$m) &&
+	git update-ref -d $m &&
+	! test -f .git/$m
+"
+rm -f .git/$m
+
 test_expect_success \
 	"fail to create $n" \
 	"touch .git/$n_dir