Imported Upstream version 2.17.0
[platform/upstream/git.git] / remote.c
index 9d34b5a..c10d87c 100644 (file)
--- a/remote.c
+++ b/remote.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "config.h"
 #include "remote.h"
 #include "refs.h"
 #include "commit.h"
@@ -21,6 +22,7 @@ static struct refspec s_tag_refspec = {
        "refs/tags/*"
 };
 
+/* See TAG_REFSPEC for the string version */
 const struct refspec *tag_refspec = &s_tag_refspec;
 
 struct counted_string {
@@ -102,6 +104,17 @@ static void add_fetch_refspec(struct remote *remote, const char *ref)
        remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
 }
 
+void add_prune_tags_to_fetch_refspec(struct remote *remote)
+{
+       int nr = remote->fetch_refspec_nr;
+       int bufsize = nr  + 1;
+       int size = sizeof(struct refspec);
+
+       remote->fetch = xrealloc(remote->fetch, size  * bufsize);
+       memcpy(&remote->fetch[nr], tag_refspec, size);
+       add_fetch_refspec(remote, xstrdup(TAG_REFSPEC));
+}
+
 static void add_url(struct remote *remote, const char *url)
 {
        ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
@@ -132,8 +145,15 @@ struct remotes_hash_key {
        int len;
 };
 
-static int remotes_hash_cmp(const struct remote *a, const struct remote *b, const struct remotes_hash_key *key)
+static int remotes_hash_cmp(const void *unused_cmp_data,
+                           const void *entry,
+                           const void *entry_or_key,
+                           const void *keydata)
 {
+       const struct remote *a = entry;
+       const struct remote *b = entry_or_key;
+       const struct remotes_hash_key *key = keydata;
+
        if (key)
                return strncmp(a->name, key->str, key->len) || a->name[key->len];
        else
@@ -143,7 +163,7 @@ static int remotes_hash_cmp(const struct remote *a, const struct remote *b, cons
 static inline void init_remotes_hash(void)
 {
        if (!remotes_hash.cmpfn)
-               hashmap_init(&remotes_hash, (hashmap_cmp_fn)remotes_hash_cmp, 0);
+               hashmap_init(&remotes_hash, remotes_hash_cmp, NULL, 0);
 }
 
 static struct remote *make_remote(const char *name, int len)
@@ -165,6 +185,7 @@ static struct remote *make_remote(const char *name, int len)
 
        ret = xcalloc(1, sizeof(struct remote));
        ret->prune = -1;  /* unspecified */
+       ret->prune_tags = -1;  /* unspecified */
        ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
        remotes[remotes_nr++] = ret;
        ret->name = xstrndup(name, len);
@@ -251,12 +272,13 @@ static const char *skip_spaces(const char *s)
 static void read_remotes_file(struct remote *remote)
 {
        struct strbuf buf = STRBUF_INIT;
-       FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
+       FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");
 
        if (!f)
                return;
+       remote->configured_in_repo = 1;
        remote->origin = REMOTE_REMOTES;
-       while (strbuf_getline(&buf, f, '\n') != EOF) {
+       while (strbuf_getline(&buf, f) != EOF) {
                const char *v;
 
                strbuf_rtrim(&buf);
@@ -276,12 +298,12 @@ static void read_branches_file(struct remote *remote)
 {
        char *frag;
        struct strbuf buf = STRBUF_INIT;
-       FILE *f = fopen(git_path("branches/%s", remote->name), "r");
+       FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");
 
        if (!f)
                return;
 
-       strbuf_getline(&buf, f, '\n');
+       strbuf_getline_lf(&buf, f);
        fclose(f);
        strbuf_trim(&buf);
        if (!buf.len) {
@@ -289,6 +311,7 @@ static void read_branches_file(struct remote *remote)
                return;
        }
 
+       remote->configured_in_repo = 1;
        remote->origin = REMOTE_BRANCHES;
 
        /*
@@ -318,93 +341,92 @@ static void read_branches_file(struct remote *remote)
 static int handle_config(const char *key, const char *value, void *cb)
 {
        const char *name;
+       int namelen;
        const char *subkey;
        struct remote *remote;
        struct branch *branch;
-       if (starts_with(key, "branch.")) {
-               name = key + 7;
-               subkey = strrchr(name, '.');
-               if (!subkey)
+       if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
+               if (!name)
                        return 0;
-               branch = make_branch(name, subkey - name);
-               if (!strcmp(subkey, ".remote")) {
+               branch = make_branch(name, namelen);
+               if (!strcmp(subkey, "remote")) {
                        return git_config_string(&branch->remote_name, key, value);
-               } else if (!strcmp(subkey, ".pushremote")) {
+               } else if (!strcmp(subkey, "pushremote")) {
                        return git_config_string(&branch->pushremote_name, key, value);
-               } else if (!strcmp(subkey, ".merge")) {
+               } else if (!strcmp(subkey, "merge")) {
                        if (!value)
                                return config_error_nonbool(key);
                        add_merge(branch, xstrdup(value));
                }
                return 0;
        }
-       if (starts_with(key, "url.")) {
+       if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
                struct rewrite *rewrite;
-               name = key + 4;
-               subkey = strrchr(name, '.');
-               if (!subkey)
+               if (!name)
                        return 0;
-               if (!strcmp(subkey, ".insteadof")) {
-                       rewrite = make_rewrite(&rewrites, name, subkey - name);
+               if (!strcmp(subkey, "insteadof")) {
+                       rewrite = make_rewrite(&rewrites, name, namelen);
                        if (!value)
                                return config_error_nonbool(key);
                        add_instead_of(rewrite, xstrdup(value));
-               } else if (!strcmp(subkey, ".pushinsteadof")) {
-                       rewrite = make_rewrite(&rewrites_push, name, subkey - name);
+               } else if (!strcmp(subkey, "pushinsteadof")) {
+                       rewrite = make_rewrite(&rewrites_push, name, namelen);
                        if (!value)
                                return config_error_nonbool(key);
                        add_instead_of(rewrite, xstrdup(value));
                }
        }
 
-       if (!starts_with(key,  "remote."))
+       if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
                return 0;
-       name = key + 7;
 
        /* Handle remote.* variables */
-       if (!strcmp(name, "pushdefault"))
+       if (!name && !strcmp(subkey, "pushdefault"))
                return git_config_string(&pushremote_name, key, value);
 
+       if (!name)
+               return 0;
        /* Handle remote.<name>.* variables */
        if (*name == '/') {
                warning("Config remote shorthand cannot begin with '/': %s",
                        name);
                return 0;
        }
-       subkey = strrchr(name, '.');
-       if (!subkey)
-               return 0;
-       remote = make_remote(name, subkey - name);
+       remote = make_remote(name, namelen);
        remote->origin = REMOTE_CONFIG;
-       if (!strcmp(subkey, ".mirror"))
+       if (current_config_scope() == CONFIG_SCOPE_REPO)
+               remote->configured_in_repo = 1;
+       if (!strcmp(subkey, "mirror"))
                remote->mirror = git_config_bool(key, value);
-       else if (!strcmp(subkey, ".skipdefaultupdate"))
+       else if (!strcmp(subkey, "skipdefaultupdate"))
                remote->skip_default_update = git_config_bool(key, value);
-       else if (!strcmp(subkey, ".skipfetchall"))
+       else if (!strcmp(subkey, "skipfetchall"))
                remote->skip_default_update = git_config_bool(key, value);
-       else if (!strcmp(subkey, ".prune"))
+       else if (!strcmp(subkey, "prune"))
                remote->prune = git_config_bool(key, value);
-       else if (!strcmp(subkey, ".url")) {
+       else if (!strcmp(subkey, "prunetags"))
+               remote->prune_tags = git_config_bool(key, value);
+       else if (!strcmp(subkey, "url")) {
                const char *v;
                if (git_config_string(&v, key, value))
                        return -1;
                add_url(remote, v);
-       } else if (!strcmp(subkey, ".pushurl")) {
+       } else if (!strcmp(subkey, "pushurl")) {
                const char *v;
                if (git_config_string(&v, key, value))
                        return -1;
                add_pushurl(remote, v);
-       } else if (!strcmp(subkey, ".push")) {
+       } else if (!strcmp(subkey, "push")) {
                const char *v;
                if (git_config_string(&v, key, value))
                        return -1;
                add_push_refspec(remote, v);
-       } else if (!strcmp(subkey, ".fetch")) {
+       } else if (!strcmp(subkey, "fetch")) {
                const char *v;
                if (git_config_string(&v, key, value))
                        return -1;
                add_fetch_refspec(remote, v);
-       } else if (!strcmp(subkey, ".receivepack")) {
+       } else if (!strcmp(subkey, "receivepack")) {
                const char *v;
                if (git_config_string(&v, key, value))
                        return -1;
@@ -412,7 +434,7 @@ static int handle_config(const char *key, const char *value, void *cb)
                        remote->receivepack = v;
                else
                        error("more than one receivepack given, using the first");
-       } else if (!strcmp(subkey, ".uploadpack")) {
+       } else if (!strcmp(subkey, "uploadpack")) {
                const char *v;
                if (git_config_string(&v, key, value))
                        return -1;
@@ -420,15 +442,18 @@ static int handle_config(const char *key, const char *value, void *cb)
                        remote->uploadpack = v;
                else
                        error("more than one uploadpack given, using the first");
-       } else if (!strcmp(subkey, ".tagopt")) {
+       } else if (!strcmp(subkey, "tagopt")) {
                if (!strcmp(value, "--no-tags"))
                        remote->fetch_tags = -1;
                else if (!strcmp(value, "--tags"))
                        remote->fetch_tags = 2;
-       } else if (!strcmp(subkey, ".proxy")) {
+       } else if (!strcmp(subkey, "proxy")) {
                return git_config_string((const char **)&remote->http_proxy,
                                         key, value);
-       } else if (!strcmp(subkey, ".vcs")) {
+       } else if (!strcmp(subkey, "proxyauthmethod")) {
+               return git_config_string((const char **)&remote->http_proxy_authmethod,
+                                        key, value);
+       } else if (!strcmp(subkey, "vcs")) {
                return git_config_string(&remote->foreign_vcs, key, value);
        }
        return 0;
@@ -456,8 +481,6 @@ static void alias_all_urls(void)
 static void read_config(void)
 {
        static int loaded;
-       struct object_id oid;
-       const char *head_ref;
        int flag;
 
        if (loaded)
@@ -465,35 +488,17 @@ static void read_config(void)
        loaded = 1;
 
        current_branch = NULL;
-       head_ref = resolve_ref_unsafe("HEAD", 0, oid.hash, &flag);
-       if (head_ref && (flag & REF_ISSYMREF) &&
-           skip_prefix(head_ref, "refs/heads/", &head_ref)) {
-               current_branch = make_branch(head_ref, 0);
+       if (startup_info->have_repository) {
+               const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
+               if (head_ref && (flag & REF_ISSYMREF) &&
+                   skip_prefix(head_ref, "refs/heads/", &head_ref)) {
+                       current_branch = make_branch(head_ref, 0);
+               }
        }
        git_config(handle_config, NULL);
        alias_all_urls();
 }
 
-/*
- * This function frees a refspec array.
- * Warning: code paths should be checked to ensure that the src
- *          and dst pointers are always freeable pointers as well
- *          as the refspec pointer itself.
- */
-static void free_refspecs(struct refspec *refspec, int nr_refspec)
-{
-       int i;
-
-       if (!refspec)
-               return;
-
-       for (i = 0; i < nr_refspec; i++) {
-               free(refspec[i].src);
-               free(refspec[i].dst);
-       }
-       free(refspec);
-}
-
 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
 {
        int i;
@@ -607,7 +612,7 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
                 * since it is only possible to reach this point from within
                 * the for loop above.
                 */
-               free_refspecs(rs, i+1);
+               free_refspec(i+1, rs);
                return NULL;
        }
        die("Invalid refspec '%s'", refspec[i]);
@@ -618,7 +623,7 @@ int valid_fetch_refspec(const char *fetch_refspec_str)
        struct refspec *refspec;
 
        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
-       free_refspecs(refspec, 1);
+       free_refspec(1, refspec);
        return !!refspec;
 }
 
@@ -627,7 +632,7 @@ struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 }
 
-static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
+struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 {
        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 }
@@ -635,6 +640,10 @@ static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 void free_refspec(int nr_refspec, struct refspec *refspec)
 {
        int i;
+
+       if (!refspec)
+               return;
+
        for (i = 0; i < nr_refspec; i++) {
                free(refspec[i].src);
                free(refspec[i].dst);
@@ -646,7 +655,12 @@ static int valid_remote_nick(const char *name)
 {
        if (!name[0] || is_dot_or_dotdot(name))
                return 0;
-       return !strchr(name, '/'); /* no slash */
+
+       /* remote nicknames cannot contain slashes */
+       while (*name)
+               if (is_dir_sep(*name++))
+                       return 0;
+       return 1;
 }
 
 const char *remote_for_branch(struct branch *branch, int *explicit)
@@ -676,6 +690,36 @@ const char *pushremote_for_branch(struct branch *branch, int *explicit)
        return remote_for_branch(branch, explicit);
 }
 
+const char *remote_ref_for_branch(struct branch *branch, int for_push,
+                                 int *explicit)
+{
+       if (branch) {
+               if (!for_push) {
+                       if (branch->merge_nr) {
+                               if (explicit)
+                                       *explicit = 1;
+                               return branch->merge_name[0];
+                       }
+               } else {
+                       const char *dst, *remote_name =
+                               pushremote_for_branch(branch, NULL);
+                       struct remote *remote = remote_get(remote_name);
+
+                       if (remote && remote->push_refspec_nr &&
+                           (dst = apply_refspecs(remote->push,
+                                                 remote->push_refspec_nr,
+                                                 branch->refname))) {
+                               if (explicit)
+                                       *explicit = 1;
+                               return dst;
+                       }
+               }
+       }
+       if (explicit)
+               *explicit = 0;
+       return "";
+}
+
 static struct remote *remote_get_1(const char *name,
                                   const char *(*get_default)(struct branch *, int *))
 {
@@ -690,7 +734,7 @@ static struct remote *remote_get_1(const char *name,
                name = get_default(current_branch, &name_given);
 
        ret = make_remote(name, 0);
-       if (valid_remote_nick(name)) {
+       if (valid_remote_nick(name) && have_git_dir()) {
                if (!valid_remote(ret))
                        read_remotes_file(ret);
                if (!valid_remote(ret))
@@ -715,18 +759,13 @@ struct remote *pushremote_get(const char *name)
        return remote_get_1(name, pushremote_for_branch);
 }
 
-int remote_is_configured(const char *name)
+int remote_is_configured(struct remote *remote, int in_repo)
 {
-       struct remotes_hash_key lookup;
-       struct hashmap_entry lookup_entry;
-       read_config();
-
-       init_remotes_hash();
-       lookup.str = name;
-       lookup.len = strlen(name);
-       hashmap_entry_init(&lookup_entry, memhash(name, lookup.len));
-
-       return hashmap_get(&remotes_hash, &lookup_entry, &lookup) != NULL;
+       if (!remote)
+               return 0;
+       if (in_repo)
+               return remote->configured_in_repo;
+       return !!remote->origin;
 }
 
 int for_each_remote(each_remote_fn fn, void *priv)
@@ -928,7 +967,7 @@ static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
                const char *name)
 {
        size_t len = strlen(name);
-       struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
+       struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
        memcpy(ref->name, prefix, prefixlen);
        memcpy(ref->name + prefixlen, name, len);
        return ref;
@@ -945,9 +984,9 @@ struct ref *copy_ref(const struct ref *ref)
        size_t len;
        if (!ref)
                return NULL;
-       len = strlen(ref->name);
-       cpy = xmalloc(sizeof(struct ref) + len + 1);
-       memcpy(cpy, ref, sizeof(struct ref) + len + 1);
+       len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
+       cpy = xmalloc(len);
+       memcpy(cpy, ref, len);
        cpy->next = NULL;
        cpy->symref = xstrdup_or_null(ref->symref);
        cpy->remote_status = xstrdup_or_null(ref->remote_status);
@@ -1090,7 +1129,7 @@ static int try_explicit_object_name(const char *name,
                return 0;
        }
 
-       if (get_sha1(name, oid.hash))
+       if (get_oid(name, &oid))
                return -1;
 
        if (match) {
@@ -1110,10 +1149,9 @@ static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 static char *guess_ref(const char *name, struct ref *peer)
 {
        struct strbuf buf = STRBUF_INIT;
-       struct object_id oid;
 
        const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
-                                          oid.hash, NULL);
+                                          NULL, NULL);
        if (!r)
                return NULL;
 
@@ -1171,12 +1209,11 @@ static int match_explicit(struct ref *src, struct ref *dst,
                return -1;
 
        if (!dst_value) {
-               struct object_id oid;
                int flag;
 
                dst_value = resolve_ref_unsafe(matched_src->name,
                                               RESOLVE_REF_READING,
-                                              oid.hash, &flag);
+                                              NULL, &flag);
                if (!dst_value ||
                    ((flag & REF_ISSYMREF) &&
                     !starts_with(dst_value, "refs/heads/")))
@@ -1193,9 +1230,10 @@ static int match_explicit(struct ref *src, struct ref *dst,
                else if (is_null_oid(&matched_src->new_oid))
                        error("unable to delete '%s': remote ref does not exist",
                              dst_value);
-               else if ((dst_guess = guess_ref(dst_value, matched_src)))
+               else if ((dst_guess = guess_ref(dst_value, matched_src))) {
                        matched_dst = make_linked_ref(dst_guess, dst_tail);
-               else
+                       free(dst_guess);
+               } else
                        error("unable to push to unqualified destination: %s\n"
                              "The destination refspec neither matches an "
                              "existing ref on the remote nor\n"
@@ -1298,7 +1336,7 @@ static void add_to_tips(struct tips *tips, const struct object_id *oid)
 
        if (is_null_oid(oid))
                return;
-       commit = lookup_commit_reference_gently(oid->hash, 1);
+       commit = lookup_commit_reference_gently(oid, 1);
        if (!commit || (commit->object.flags & TMP_MARK))
                return;
        commit->object.flags |= TMP_MARK;
@@ -1360,7 +1398,8 @@ static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***ds
 
                        if (is_null_oid(&ref->new_oid))
                                continue;
-                       commit = lookup_commit_reference_gently(ref->new_oid.hash, 1);
+                       commit = lookup_commit_reference_gently(&ref->new_oid,
+                                                               1);
                        if (!commit)
                                /* not pushing a commit, which is not an error */
                                continue;
@@ -1545,11 +1584,8 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
                }
 
                /*
-                * Bypass the usual "must fast-forward" check but
-                * replace it with a weaker "the old value must be
-                * this value we observed".  If the remote ref has
-                * moved and is now different from what we expect,
-                * reject any push.
+                * If the remote ref has moved and is now different
+                * from what we expect, reject any push.
                 *
                 * It also is an error if the user told us to check
                 * with the remote-tracking branch to find the value
@@ -1557,13 +1593,16 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
                 * branch.
                 */
                if (ref->expect_old_sha1) {
-                       if (ref->expect_old_no_trackback ||
-                           oidcmp(&ref->old_oid, &ref->old_oid_expect))
+                       if (oidcmp(&ref->old_oid, &ref->old_oid_expect))
                                reject_reason = REF_STATUS_REJECT_STALE;
+                       else
+                               /* If the ref isn't stale then force the update. */
+                               force_ref_update = 1;
                }
 
                /*
-                * The usual "must fast-forward" rules.
+                * If the update isn't already rejected then check
+                * the usual "must fast-forward" rules.
                 *
                 * Decide whether an individual refspec A:B can be
                 * pushed.  The push will succeed if any of the
@@ -1582,13 +1621,13 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
                 *     passing the --force argument
                 */
 
-               else if (!ref->deletion && !is_null_oid(&ref->old_oid)) {
+               if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
                        if (starts_with(ref->name, "refs/tags/"))
                                reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
                        else if (!has_object_file(&ref->old_oid))
                                reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
-                       else if (!lookup_commit_reference_gently(ref->old_oid.hash, 1) ||
-                                !lookup_commit_reference_gently(ref->new_oid.hash, 1))
+                       else if (!lookup_commit_reference_gently(&ref->old_oid, 1) ||
+                                !lookup_commit_reference_gently(&ref->new_oid, 1))
                                reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
                        else if (!ref_newer(&ref->new_oid, &ref->old_oid))
                                reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
@@ -1635,7 +1674,7 @@ static void set_merge(struct branch *ret)
                    strcmp(ret->remote_name, "."))
                        continue;
                if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
-                            oid.hash, &ref) == 1)
+                            &oid, &ref) == 1)
                        ret->merge[i]->dst = ref;
                else
                        ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
@@ -1669,7 +1708,7 @@ int branch_merge_matches(struct branch *branch,
        return refname_match(branch->merge[i]->src, refname);
 }
 
-__attribute((format (printf,2,3)))
+__attribute__((format (printf,2,3)))
 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
 {
        if (err) {
@@ -1726,9 +1765,6 @@ static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
 {
        struct remote *remote;
 
-       if (!branch)
-               return error_buf(err, _("HEAD does not point to a branch"));
-
        remote = remote_get(pushremote_for_branch(branch, NULL));
        if (!remote)
                return error_buf(err,
@@ -1788,6 +1824,9 @@ static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
 
 const char *branch_get_push(struct branch *branch, struct strbuf *err)
 {
+       if (!branch)
+               return error_buf(err, _("HEAD does not point to a branch"));
+
        if (!branch->push_tracking_ref)
                branch->push_tracking_ref = branch_get_push_1(branch, err);
        return branch->push_tracking_ref;
@@ -1795,10 +1834,9 @@ const char *branch_get_push(struct branch *branch, struct strbuf *err)
 
 static int ignore_symref_update(const char *refname)
 {
-       struct object_id oid;
        int flag;
 
-       if (!resolve_ref_unsafe(refname, 0, oid.hash, &flag))
+       if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
                return 0; /* non-existing refs are OK */
        return (flag & REF_ISSYMREF);
 }
@@ -1947,33 +1985,33 @@ static void unmark_and_free(struct commit_list *list, unsigned int mark)
 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
 {
        struct object *o;
-       struct commit *old, *new;
+       struct commit *old_commit, *new_commit;
        struct commit_list *list, *used;
        int found = 0;
 
        /*
-        * Both new and old must be commit-ish and new is descendant of
-        * old.  Otherwise we require --force.
+        * Both new_commit and old_commit must be commit-ish and new_commit is descendant of
+        * old_commit.  Otherwise we require --force.
         */
-       o = deref_tag(parse_object(old_oid->hash), NULL, 0);
+       o = deref_tag(parse_object(old_oid), NULL, 0);
        if (!o || o->type != OBJ_COMMIT)
                return 0;
-       old = (struct commit *) o;
+       old_commit = (struct commit *) o;
 
-       o = deref_tag(parse_object(new_oid->hash), NULL, 0);
+       o = deref_tag(parse_object(new_oid), NULL, 0);
        if (!o || o->type != OBJ_COMMIT)
                return 0;
-       new = (struct commit *) o;
+       new_commit = (struct commit *) o;
 
-       if (parse_commit(new) < 0)
+       if (parse_commit(new_commit) < 0)
                return 0;
 
        used = list = NULL;
-       commit_list_insert(new, &list);
+       commit_list_insert(new_commit, &list);
        while (list) {
-               new = pop_most_recent_commit(&list, TMP_MARK);
-               commit_list_insert(new, &used);
-               if (new == old) {
+               new_commit = pop_most_recent_commit(&list, TMP_MARK);
+               commit_list_insert(new_commit, &used);
+               if (new_commit == old_commit) {
                        found = 1;
                        break;
                }
@@ -1984,16 +2022,23 @@ int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid)
 }
 
 /*
- * Compare a branch with its upstream, and save their differences (number
- * of commits) in *num_ours and *num_theirs. The name of the upstream branch
- * (or NULL if no upstream is defined) is returned via *upstream_name, if it
- * is not itself NULL.
+ * Lookup the upstream branch for the given branch and if present, optionally
+ * compute the commit ahead/behind values for the pair.
+ *
+ * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
+ * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
+ * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
+ * set to zero).
+ *
+ * The name of the upstream branch (or NULL if no upstream is defined) is
+ * returned via *upstream_name, if it is not itself NULL.
  *
  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
- * upstream defined, or ref does not exist), 0 otherwise.
+ * upstream defined, or ref does not exist).  Returns 0 if the commits are
+ * identical.  Returns 1 if commits are different.
  */
 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
-                      const char **upstream_name)
+                      const char **upstream_name, enum ahead_behind_flags abf)
 {
        struct object_id oid;
        struct commit *ours, *theirs;
@@ -2009,23 +2054,27 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
                return -1;
 
        /* Cannot stat if what we used to build on no longer exists */
-       if (read_ref(base, oid.hash))
+       if (read_ref(base, &oid))
                return -1;
-       theirs = lookup_commit_reference(oid.hash);
+       theirs = lookup_commit_reference(&oid);
        if (!theirs)
                return -1;
 
-       if (read_ref(branch->refname, oid.hash))
+       if (read_ref(branch->refname, &oid))
                return -1;
-       ours = lookup_commit_reference(oid.hash);
+       ours = lookup_commit_reference(&oid);
        if (!ours)
                return -1;
 
+       *num_theirs = *num_ours = 0;
+
        /* are we the same? */
-       if (theirs == ours) {
-               *num_theirs = *num_ours = 0;
+       if (theirs == ours)
                return 0;
-       }
+       if (abf == AHEAD_BEHIND_QUICK)
+               return 1;
+       if (abf != AHEAD_BEHIND_FULL)
+               BUG("stat_tracking_info: invalid abf '%d'", abf);
 
        /* Run "rev-list --left-right ours...theirs" internally... */
        argv_array_push(&argv, ""); /* ignored */
@@ -2041,8 +2090,6 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
                die("revision walk setup failed");
 
        /* ... and count the commits on each side. */
-       *num_ours = 0;
-       *num_theirs = 0;
        while (1) {
                struct commit *c = get_revision(&revs);
                if (!c)
@@ -2058,20 +2105,22 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
        clear_commit_marks(theirs, ALL_REV_FLAGS);
 
        argv_array_clear(&argv);
-       return 0;
+       return 1;
 }
 
 /*
  * Return true when there is anything to report, otherwise false.
  */
-int format_tracking_info(struct branch *branch, struct strbuf *sb)
+int format_tracking_info(struct branch *branch, struct strbuf *sb,
+                        enum ahead_behind_flags abf)
 {
-       int ours, theirs;
+       int ours, theirs, sti;
        const char *full_base;
        char *base;
        int upstream_is_gone = 0;
 
-       if (stat_tracking_info(branch, &ours, &theirs, &full_base) < 0) {
+       sti = stat_tracking_info(branch, &ours, &theirs, &full_base, abf);
+       if (sti < 0) {
                if (!full_base)
                        return 0;
                upstream_is_gone = 1;
@@ -2083,12 +2132,19 @@ int format_tracking_info(struct branch *branch, struct strbuf *sb)
                        _("Your branch is based on '%s', but the upstream is gone.\n"),
                        base);
                if (advice_status_hints)
-                       strbuf_addf(sb,
+                       strbuf_addstr(sb,
                                _("  (use \"git branch --unset-upstream\" to fixup)\n"));
-       } else if (!ours && !theirs) {
+       } else if (!sti) {
                strbuf_addf(sb,
-                       _("Your branch is up-to-date with '%s'.\n"),
+                       _("Your branch is up to date with '%s'.\n"),
                        base);
+       } else if (abf == AHEAD_BEHIND_QUICK) {
+               strbuf_addf(sb,
+                           _("Your branch and '%s' refer to different commits.\n"),
+                           base);
+               if (advice_status_hints)
+                       strbuf_addf(sb, _("  (use \"%s\" for details)\n"),
+                                   "git status --ahead-behind");
        } else if (!theirs) {
                strbuf_addf(sb,
                        Q_("Your branch is ahead of '%s' by %d commit.\n",
@@ -2096,7 +2152,7 @@ int format_tracking_info(struct branch *branch, struct strbuf *sb)
                           ours),
                        base, ours);
                if (advice_status_hints)
-                       strbuf_addf(sb,
+                       strbuf_addstr(sb,
                                _("  (use \"git push\" to publish your local commits)\n"));
        } else if (!ours) {
                strbuf_addf(sb,
@@ -2107,7 +2163,7 @@ int format_tracking_info(struct branch *branch, struct strbuf *sb)
                           theirs),
                        base, theirs);
                if (advice_status_hints)
-                       strbuf_addf(sb,
+                       strbuf_addstr(sb,
                                _("  (use \"git pull\" to update your local branch)\n"));
        } else {
                strbuf_addf(sb,
@@ -2117,10 +2173,10 @@ int format_tracking_info(struct branch *branch, struct strbuf *sb)
                           "Your branch and '%s' have diverged,\n"
                               "and have %d and %d different commits each, "
                               "respectively.\n",
-                          theirs),
+                          ours + theirs),
                        base, ours, theirs);
                if (advice_status_hints)
-                       strbuf_addf(sb,
+                       strbuf_addstr(sb,
                                _("  (use \"git pull\" to merge the remote branch into yours)\n"));
        }
        free(base);
@@ -2132,16 +2188,13 @@ static int one_local_ref(const char *refname, const struct object_id *oid,
 {
        struct ref ***local_tail = cb_data;
        struct ref *ref;
-       int len;
 
        /* we already know it starts with refs/ to get here */
        if (check_refname_format(refname + 5, 0))
                return 0;
 
-       len = strlen(refname) + 1;
-       ref = xcalloc(1, sizeof(*ref) + len);
+       ref = alloc_ref(refname);
        oidcpy(&ref->new_oid, oid);
-       memcpy(ref->name, refname, len);
        **local_tail = ref;
        *local_tail = &ref->next;
        return 0;
@@ -2284,7 +2337,7 @@ static struct push_cas *add_cas_entry(struct push_cas_option *cas,
        return entry;
 }
 
-int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
+static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
 {
        const char *colon;
        struct push_cas *entry;
@@ -2306,7 +2359,9 @@ int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unse
        entry = add_cas_entry(cas, arg, colon - arg);
        if (!*colon)
                entry->use_tracking = 1;
-       else if (get_sha1(colon + 1, entry->expect))
+       else if (!colon[1])
+               oidclr(&entry->expect);
+       else if (get_oid(colon + 1, &entry->expect))
                return error("cannot parse expected object name '%s'", colon + 1);
        return 0;
 }
@@ -2335,7 +2390,7 @@ static int remote_tracking(struct remote *remote, const char *refname,
        dst = apply_refspecs(remote->fetch, remote->fetch_refspec_nr, refname);
        if (!dst)
                return -1; /* no tracking ref for refname at remote */
-       if (read_ref(dst, oid->hash))
+       if (read_ref(dst, oid))
                return -1; /* we know what the tracking ref is but we cannot read it */
        return 0;
 }
@@ -2353,9 +2408,9 @@ static void apply_cas(struct push_cas_option *cas,
                        continue;
                ref->expect_old_sha1 = 1;
                if (!entry->use_tracking)
-                       hashcpy(ref->old_oid_expect.hash, cas->entry[i].expect);
+                       oidcpy(&ref->old_oid_expect, &entry->expect);
                else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
-                       ref->expect_old_no_trackback = 1;
+                       oidclr(&ref->old_oid_expect);
                return;
        }
 
@@ -2365,7 +2420,7 @@ static void apply_cas(struct push_cas_option *cas,
 
        ref->expect_old_sha1 = 1;
        if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
-               ref->expect_old_no_trackback = 1;
+               oidclr(&ref->old_oid_expect);
 }
 
 void apply_push_cas(struct push_cas_option *cas,