Documentation: describe shallow repository

diff --git a/builtin-update-ref.c b/builtin-update-ref.c
index 00333c7e7ca0e706be425182ff92b98a16ac3883..b34e5987dd256e0b7d9fae46fe89f66dd18ad91f 100644 (file)
--- a/builtin-update-ref.c
+++ b/builtin-update-ref.c
@@ -3,16 +3,17 @@
 #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, char **envp)
+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;
 
-       setup_git_directory();
+       delete = 0;
+       setup_ident();
        git_config(git_default_config);
 
        for (i = 1; i < argc; i++) {
@@ -26,6 +27,10 @@ int cmd_update_ref(int argc, const char **argv, char **envp)
                                die("Refusing to perform update with \\n in message.");
                        continue;
                }
+               if (!strcmp("-d", argv[i])) {
+                       delete = 1;
+                       continue;
+               }
                if (!refname) {
                        refname = argv[i];
                        continue;
@@ -44,11 +49,18 @@ int cmd_update_ref(int argc, const char **argv, char **envp)
 
        if (get_sha1(value, sha1))
                die("%s: not a valid SHA1", value);
-       memset(oldsha1, 0, 20);
-       if (oldval && get_sha1(oldval, oldsha1))
+
+       if (delete) {
+               if (oldval)
+                       usage(git_update_ref_usage);
+               return delete_ref(refname, sha1);
+       }
+
+       hashclr(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, 0);
+       lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL);
        if (!lock)
                return 1;
        if (write_ref_sha1(lock, sha1, msg) < 0)