update-ref: -d flag and ref creation safety.
This adds -d flag to update-ref to allow safe deletion of ref.
Before deleting it, the command checks if the given <oldvalue>
still matches the value the caller thought the ref contained.
Similarly, it also accepts 0{40} or an empty string as <oldvalue>
to allow safe creation of a new ref.
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/builtin-update-ref.c b/builtin-update-ref.c
index ab52833..b34e598 100644
--- a/builtin-update-ref.c
+++ b/builtin-update-ref.c
@@ -3,15 +3,16 @@
#include "builtin.h"
static const char git_update_ref_usage[] =
-"git-update-ref <refname> <value> [<oldval>] [-m <reason>]";
+"git-update-ref [-m <reason>] (-d <refname> <value> | <refname> <value> [<oldval>])";
int cmd_update_ref(int argc, const char **argv, const char *prefix)
{
const char *refname=NULL, *value=NULL, *oldval=NULL, *msg=NULL;
struct ref_lock *lock;
unsigned char sha1[20], oldsha1[20];
- int i;
+ int i, delete;
+ delete = 0;
setup_ident();
git_config(git_default_config);
@@ -26,6 +27,10 @@
die("Refusing to perform update with \\n in message.");
continue;
}
+ if (!strcmp("-d", argv[i])) {
+ delete = 1;
+ continue;
+ }
if (!refname) {
refname = argv[i];
continue;
@@ -44,8 +49,15 @@
if (get_sha1(value, sha1))
die("%s: not a valid SHA1", value);
+
+ if (delete) {
+ if (oldval)
+ usage(git_update_ref_usage);
+ return delete_ref(refname, sha1);
+ }
+
hashclr(oldsha1);
- if (oldval && get_sha1(oldval, oldsha1))
+ if (oldval && *oldval && get_sha1(oldval, oldsha1))
die("%s: not a valid old SHA1", oldval);
lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL);
