replace: refactor checking ref validity

This will be useful in a following commit when we will
want to check if the ref already exists before we let the
user edit an object.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/replace.c b/builtin/replace.c
index 07518040395139e9e159617bd7c2da548237bbbf..3d6edaf7c7787c04cddf5a092e708dce71295e2e 100644 (file)
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -124,6 +124,25 @@ static int delete_replace_ref(const char *name, const char *ref,
        return 0;
 }
 
+static void check_ref_valid(unsigned char object[20],
+                           unsigned char prev[20],
+                           char *ref,
+                           int ref_size,
+                           int force)
+{
+       if (snprintf(ref, ref_size,
+                    "refs/replace/%s",
+                    sha1_to_hex(object)) > ref_size - 1)
+               die("replace ref name too long: %.*s...", 50, ref);
+       if (check_refname_format(ref, 0))
+               die("'%s' is not a valid ref name.", ref);
+
+       if (read_ref(ref, prev))
+               hashclr(prev);
+       else if (!force)
+               die("replace ref '%s' already exists", ref);
+}
+
 static int replace_object_sha1(const char *object_ref,
                               unsigned char object[20],
                               const char *replace_ref,
@@ -135,13 +154,6 @@ static int replace_object_sha1(const char *object_ref,
        char ref[PATH_MAX];
        struct ref_lock *lock;
 
-       if (snprintf(ref, sizeof(ref),
-                    "refs/replace/%s",
-                    sha1_to_hex(object)) > sizeof(ref) - 1)
-               die("replace ref name too long: %.*s...", 50, ref);
-       if (check_refname_format(ref, 0))
-               die("'%s' is not a valid ref name.", ref);
-
        obj_type = sha1_object_info(object, NULL);
        repl_type = sha1_object_info(repl, NULL);
        if (!force && obj_type != repl_type)
@@ -151,10 +163,7 @@ static int replace_object_sha1(const char *object_ref,
                    object_ref, typename(obj_type),
                    replace_ref, typename(repl_type));
 
-       if (read_ref(ref, prev))
-               hashclr(prev);
-       else if (!force)
-               die("replace ref '%s' already exists", ref);
+       check_ref_valid(object, prev, ref, sizeof(ref), force);
 
        lock = lock_any_ref_for_update(ref, prev, 0, NULL);
        if (!lock)