commit: allow associating auxiliary info on-demand

diff --git a/remote.c b/remote.c
index ca1f8f2eafbef40046f2890501ad757bde9585f1..e53a6eb7769e2884f77819c73423c31e49b0114e 100644 (file)
--- a/remote.c
+++ b/remote.c
@@ -1285,6 +1285,8 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
        struct ref *ref;
 
        for (ref = remote_refs; ref; ref = ref->next) {
+               int force_ref_update = ref->force || force_update;
+
                if (ref->peer_ref)
                        hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
                else if (!send_mirror)
@@ -1297,34 +1299,41 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
                        continue;
                }
 
-               /* This part determines what can overwrite what.
-                * The rules are:
-                *
-                * (0) you can always use --force or +A:B notation to
-                *     selectively force individual ref pairs.
+               /*
+                * Decide whether an individual refspec A:B can be
+                * pushed.  The push will succeed if any of the
+                * following are true:
                 *
-                * (1) if the old thing does not exist, it is OK.
+                * (1) the remote reference B does not exist
                 *
-                * (2) if you do not have the old thing, you are not allowed
-                *     to overwrite it; you would not know what you are losing
-                *     otherwise.
+                * (2) the remote reference B is being removed (i.e.,
+                *     pushing :B where no source is specified)
                 *
-                * (3) if both new and old are commit-ish, and new is a
-                *     descendant of old, it is OK.
+                * (3) the destination is not under refs/tags/, and
+                *     if the old and new value is a commit, the new
+                *     is a descendant of the old.
                 *
-                * (4) regardless of all of the above, removing :B is
-                *     always allowed.
+                * (4) it is forced using the +A:B notation, or by
+                *     passing the --force argument
                 */
 
-               ref->nonfastforward =
-                       !ref->deletion &&
-                       !is_null_sha1(ref->old_sha1) &&
-                       (!has_sha1_file(ref->old_sha1)
-                         || !ref_newer(ref->new_sha1, ref->old_sha1));
-
-               if (ref->nonfastforward && !ref->force && !force_update) {
-                       ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
-                       continue;
+               if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
+                       int why = 0; /* why would this push require --force? */
+
+                       if (!prefixcmp(ref->name, "refs/tags/"))
+                               why = REF_STATUS_REJECT_ALREADY_EXISTS;
+                       else if (!has_sha1_file(ref->old_sha1))
+                               why = REF_STATUS_REJECT_FETCH_FIRST;
+                       else if (!lookup_commit_reference_gently(ref->old_sha1, 1) ||
+                                !lookup_commit_reference_gently(ref->new_sha1, 1))
+                               why = REF_STATUS_REJECT_NEEDS_FORCE;
+                       else if (!ref_newer(ref->new_sha1, ref->old_sha1))
+                               why = REF_STATUS_REJECT_NONFASTFORWARD;
+
+                       if (!force_ref_update)
+                               ref->status = why;
+                       else if (why)
+                               ref->forced_update = 1;
                }
        }
 }
@@ -1518,7 +1527,8 @@ int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
        struct commit_list *list, *used;
        int found = 0;
 
-       /* Both new and old must be commit-ish and new is descendant of
+       /*
+        * Both new and old must be commit-ish and new is descendant of
         * old.  Otherwise we require --force.
         */
        o = deref_tag(parse_object(old_sha1), NULL, 0);