X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;ds=sidebyside;f=remote.c;h=d7079c6dd871dc1b482d347d013438fe30cc0908;hb=8851f4800c15fe91b6a53e9e284787b983226c41;hp=2d9af4023eba6f8b2fe528ccbf03569fcaa265ee;hpb=92798702cf6d201f80e257a07d0a0c40565c79fe;p=git.git

diff --git a/remote.c b/remote.c
index 2d9af4023..d7079c6dd 100644
--- a/remote.c
+++ b/remote.c
@@ -1,6 +1,20 @@
 #include "cache.h"
 #include "remote.h"
 #include "refs.h"
+#include "commit.h"
+#include "diff.h"
+#include "revision.h"
+#include "dir.h"
+
+static struct refspec s_tag_refspec = {
+	0,
+	1,
+	0,
+	"refs/tags/",
+	"refs/tags/"
+};
+
+const struct refspec *tag_refspec = &s_tag_refspec;
 
 struct counted_string {
 	size_t len;
@@ -56,7 +70,7 @@ static const char *alias_url(const char *url)
 	if (!longest)
 		return url;
 
-	ret = malloc(rewrite[longest_i]->baselen +
+	ret = xmalloc(rewrite[longest_i]->baselen +
 		     (strlen(url) - longest->len) + 1);
 	strcpy(ret, rewrite[longest_i]->base);
 	strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
@@ -139,7 +153,7 @@ static struct branch *make_branch(const char *name, int len)
 		ret->name = xstrndup(name, len);
 	else
 		ret->name = xstrdup(name);
-	refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
+	refname = xmalloc(strlen(name) + strlen("refs/heads/") + 1);
 	strcpy(refname, "refs/heads/");
 	strcpy(refname + strlen("refs/heads/"), ret->name);
 	ret->refname = refname;
@@ -188,6 +202,7 @@ static void read_remotes_file(struct remote *remote)
 
 	if (!f)
 		return;
+	remote->origin = REMOTE_REMOTES;
 	while (fgets(buffer, BUF_SIZE, f)) {
 		int value_list;
 		char *s, *p;
@@ -232,7 +247,7 @@ static void read_branches_file(struct remote *remote)
 {
 	const char *slash = strchr(remote->name, '/');
 	char *frag;
-	struct strbuf branch;
+	struct strbuf branch = STRBUF_INIT;
 	int n = slash ? slash - remote->name : 1000;
 	FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
 	char *s, *p;
@@ -248,6 +263,7 @@ static void read_branches_file(struct remote *remote)
 		s++;
 	if (!*s)
 		return;
+	remote->origin = REMOTE_BRANCHES;
 	p = s + strlen(s);
 	while (isspace(p[-1]))
 		*--p = 0;
@@ -270,7 +286,6 @@ static void read_branches_file(struct remote *remote)
 	 * #branch specified.  The "master" (or specified) branch is
 	 * fetched and stored in the local branch of the same name.
 	 */
-	strbuf_init(&branch, 0);
 	frag = strchr(p, '#');
 	if (frag) {
 		*(frag++) = '\0';
@@ -285,10 +300,21 @@ static void read_branches_file(struct remote *remote)
 	}
 	add_url_alias(remote, p);
 	add_fetch_refspec(remote, strbuf_detach(&branch, 0));
+	/*
+	 * Cogito compatible push: push current HEAD to remote #branch
+	 * (master if missing)
+	 */
+	strbuf_init(&branch, 0);
+	strbuf_addstr(&branch, "HEAD");
+	if (frag)
+		strbuf_addf(&branch, ":refs/heads/%s", frag);
+	else
+		strbuf_addstr(&branch, ":refs/heads/master");
+	add_push_refspec(remote, strbuf_detach(&branch, 0));
 	remote->fetch_tags = 1; /* always auto-follow */
 }
 
-static int handle_config(const char *key, const char *value)
+static int handle_config(const char *key, const char *value, void *cb)
 {
 	const char *name;
 	const char *subkey;
@@ -329,52 +355,59 @@ static int handle_config(const char *key, const char *value)
 	if (prefixcmp(key,  "remote."))
 		return 0;
 	name = key + 7;
+	if (*name == '/') {
+		warning("Config remote shorthand cannot begin with '/': %s",
+			name);
+		return 0;
+	}
 	subkey = strrchr(name, '.');
 	if (!subkey)
 		return error("Config with no key for remote %s", name);
-	if (*subkey == '/') {
-		warning("Config remote shorthand cannot begin with '/': %s", name);
-		return 0;
-	}
 	remote = make_remote(name, subkey - name);
-	if (!value) {
-		/* if we ever have a boolean variable, e.g. "remote.*.disabled"
-		 * [remote "frotz"]
-		 *      disabled
-		 * is a valid way to set it to true; we get NULL in value so
-		 * we need to handle it here.
-		 *
-		 * if (!strcmp(subkey, ".disabled")) {
-		 *      val = git_config_bool(key, value);
-		 *      return 0;
-		 * } else
-		 *
-		 */
-		return 0; /* ignore unknown booleans */
-	}
-	if (!strcmp(subkey, ".url")) {
-		add_url(remote, xstrdup(value));
+	remote->origin = REMOTE_CONFIG;
+	if (!strcmp(subkey, ".mirror"))
+		remote->mirror = git_config_bool(key, value);
+	else if (!strcmp(subkey, ".skipdefaultupdate"))
+		remote->skip_default_update = 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, ".push")) {
-		add_push_refspec(remote, xstrdup(value));
+		const char *v;
+		if (git_config_string(&v, key, value))
+			return -1;
+		add_push_refspec(remote, v);
 	} else if (!strcmp(subkey, ".fetch")) {
-		add_fetch_refspec(remote, xstrdup(value));
+		const char *v;
+		if (git_config_string(&v, key, value))
+			return -1;
+		add_fetch_refspec(remote, v);
 	} else if (!strcmp(subkey, ".receivepack")) {
+		const char *v;
+		if (git_config_string(&v, key, value))
+			return -1;
 		if (!remote->receivepack)
-			remote->receivepack = xstrdup(value);
+			remote->receivepack = v;
 		else
 			error("more than one receivepack given, using the first");
 	} else if (!strcmp(subkey, ".uploadpack")) {
+		const char *v;
+		if (git_config_string(&v, key, value))
+			return -1;
 		if (!remote->uploadpack)
-			remote->uploadpack = xstrdup(value);
+			remote->uploadpack = v;
 		else
 			error("more than one uploadpack given, using the first");
 	} else if (!strcmp(subkey, ".tagopt")) {
 		if (!strcmp(value, "--no-tags"))
 			remote->fetch_tags = -1;
 	} else if (!strcmp(subkey, ".proxy")) {
-		remote->http_proxy = xstrdup(value);
-	} else if (!strcmp(subkey, ".skipdefaultupdate"))
-		remote->skip_default_update = 1;
+		return git_config_string((const char **)&remote->http_proxy,
+					 key, value);
+	}
 	return 0;
 }
 
@@ -405,10 +438,52 @@ static void read_config(void)
 		current_branch =
 			make_branch(head_ref + strlen("refs/heads/"), 0);
 	}
-	git_config(handle_config);
+	git_config(handle_config, NULL);
 	alias_all_urls();
 }
 
+/*
+ * We need to make sure the tracking branches are well formed, but a
+ * wildcard refspec in "struct refspec" must have a trailing slash. We
+ * temporarily drop the trailing '/' while calling check_ref_format(),
+ * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
+ * error return is Ok for a wildcard refspec.
+ */
+static int verify_refname(char *name, int is_glob)
+{
+	int result, len = -1;
+
+	if (is_glob) {
+		len = strlen(name);
+		assert(name[len - 1] == '/');
+		name[len - 1] = '\0';
+	}
+	result = check_ref_format(name);
+	if (is_glob)
+		name[len - 1] = '/';
+	return result;
+}
+
+/*
+ * 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;
@@ -416,11 +491,11 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
 	struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
 
 	for (i = 0; i < nr_refspec; i++) {
-		size_t llen, rlen;
+		size_t llen;
 		int is_glob;
 		const char *lhs, *rhs;
 
-		llen = rlen = is_glob = 0;
+		llen = is_glob = 0;
 
 		lhs = refspec[i];
 		if (*lhs == '+') {
@@ -429,13 +504,20 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
 		}
 
 		rhs = strrchr(lhs, ':');
+
+		/*
+		 * Before going on, special case ":" (or "+:") as a refspec
+		 * for matching refs.
+		 */
+		if (!fetch && rhs == lhs && rhs[1] == '\0') {
+			rs[i].matching = 1;
+			continue;
+		}
+
 		if (rhs) {
-			rhs++;
-			rlen = strlen(rhs);
+			size_t rlen = strlen(++rhs);
 			is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
-			if (is_glob)
-				rlen -= 2;
-			rs[i].dst = xstrndup(rhs, rlen);
+			rs[i].dst = xstrndup(rhs, rlen - is_glob);
 		}
 
 		llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
@@ -443,7 +525,7 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
 			if ((rhs && !is_glob) || (!rhs && fetch))
 				goto invalid;
 			is_glob = 1;
-			llen -= 2;
+			llen--;
 		} else if (rhs && is_glob) {
 			goto invalid;
 		}
@@ -460,7 +542,7 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
 			if (!*rs[i].src)
 				; /* empty is ok */
 			else {
-				st = check_ref_format(rs[i].src);
+				st = verify_refname(rs[i].src, is_glob);
 				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 					goto invalid;
 			}
@@ -475,7 +557,7 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
 			} else if (!*rs[i].dst) {
 				; /* ok */
 			} else {
-				st = check_ref_format(rs[i].dst);
+				st = verify_refname(rs[i].dst, is_glob);
 				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 					goto invalid;
 			}
@@ -490,7 +572,7 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
 			if (!*rs[i].src)
 				; /* empty is ok */
 			else if (is_glob) {
-				st = check_ref_format(rs[i].src);
+				st = verify_refname(rs[i].src, is_glob);
 				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 					goto invalid;
 			}
@@ -504,13 +586,13 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
 			 * - otherwise it must be a valid looking ref.
 			 */
 			if (!rs[i].dst) {
-				st = check_ref_format(rs[i].src);
+				st = verify_refname(rs[i].src, is_glob);
 				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 					goto invalid;
 			} else if (!*rs[i].dst) {
 				goto invalid;
 			} else {
-				st = check_ref_format(rs[i].dst);
+				st = verify_refname(rs[i].dst, is_glob);
 				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
 					goto invalid;
 			}
@@ -520,7 +602,12 @@ static struct refspec *parse_refspec_internal(int nr_refspec, const char **refsp
 
  invalid:
 	if (verify) {
-		free(rs);
+		/*
+		 * nr_refspec must be greater than zero and i must be valid
+		 * since it is only possible to reach this point from within
+		 * the for loop above.
+		 */
+		free_refspecs(rs, i+1);
 		return NULL;
 	}
 	die("Invalid refspec '%s'", refspec[i]);
@@ -532,8 +619,7 @@ int valid_fetch_refspec(const char *fetch_refspec_str)
 	struct refspec *refspec;
 
 	refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
-	if (refspec)
-		free(refspec);
+	free_refspecs(refspec, 1);
 	return !!refspec;
 }
 
@@ -542,17 +628,14 @@ struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
 	return parse_refspec_internal(nr_refspec, refspec, 1, 0);
 }
 
-struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
+static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
 {
 	return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 }
 
 static int valid_remote_nick(const char *name)
 {
-	if (!name[0] || /* not empty */
-	    (name[0] == '.' && /* not "." */
-	     (!name[1] || /* not ".." */
-	      (name[1] == '.' && !name[2]))))
+	if (!name[0] || is_dot_or_dotdot(name))
 		return 0;
 	return !strchr(name, '/'); /* no slash */
 }
@@ -659,8 +742,7 @@ int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 		if (!fetch->dst)
 			continue;
 		if (fetch->pattern) {
-			if (!prefixcmp(needle, key) &&
-			    needle[strlen(key)] == '/') {
+			if (!prefixcmp(needle, key)) {
 				*result = xmalloc(strlen(value) +
 						  strlen(needle) -
 						  strlen(key) + 1);
@@ -679,11 +761,19 @@ int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 	return -1;
 }
 
-struct ref *alloc_ref(unsigned namelen)
+static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
+		const char *name)
 {
-	struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
-	memset(ret, 0, sizeof(struct ref) + namelen);
-	return ret;
+	size_t len = strlen(name);
+	struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1);
+	memcpy(ref->name, prefix, prefixlen);
+	memcpy(ref->name + prefixlen, name, len);
+	return ref;
+}
+
+struct ref *alloc_ref(const char *name)
+{
+	return alloc_ref_with_prefix("", 0, name);
 }
 
 static struct ref *copy_ref(const struct ref *ref)
@@ -706,13 +796,22 @@ struct ref *copy_ref_list(const struct ref *ref)
 	return ret;
 }
 
+static void free_ref(struct ref *ref)
+{
+	if (!ref)
+		return;
+	free(ref->remote_status);
+	free(ref->symref);
+	free(ref);
+}
+
 void free_refs(struct ref *ref)
 {
 	struct ref *next;
 	while (ref) {
 		next = ref->next;
 		free(ref->peer_ref);
-		free(ref);
+		free_ref(ref);
 		ref = next;
 	}
 }
@@ -783,31 +882,22 @@ static struct ref *try_explicit_object_name(const char *name)
 {
 	unsigned char sha1[20];
 	struct ref *ref;
-	int len;
 
 	if (!*name) {
-		ref = alloc_ref(20);
-		strcpy(ref->name, "(delete)");
+		ref = alloc_ref("(delete)");
 		hashclr(ref->new_sha1);
 		return ref;
 	}
 	if (get_sha1(name, sha1))
 		return NULL;
-	len = strlen(name) + 1;
-	ref = alloc_ref(len);
-	memcpy(ref->name, name, len);
+	ref = alloc_ref(name);
 	hashcpy(ref->new_sha1, sha1);
 	return ref;
 }
 
 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 {
-	struct ref *ret;
-	size_t len;
-
-	len = strlen(name) + 1;
-	ret = alloc_ref(len);
-	memcpy(ret->name, name, len);
+	struct ref *ret = alloc_ref(name);
 	tail_link_ref(ret, tail);
 	return ret;
 }
@@ -834,16 +924,15 @@ static char *guess_ref(const char *name, struct ref *peer)
 
 static int match_explicit(struct ref *src, struct ref *dst,
 			  struct ref ***dst_tail,
-			  struct refspec *rs,
-			  int errs)
+			  struct refspec *rs)
 {
 	struct ref *matched_src, *matched_dst;
 
 	const char *dst_value = rs->dst;
 	char *dst_guess;
 
-	if (rs->pattern)
-		return errs;
+	if (rs->pattern || rs->matching)
+		return 0;
 
 	matched_src = matched_dst = NULL;
 	switch (count_refspec_match(rs->src, src, &matched_src)) {
@@ -856,23 +945,16 @@ static int match_explicit(struct ref *src, struct ref *dst,
 		 */
 		matched_src = try_explicit_object_name(rs->src);
 		if (!matched_src)
-			error("src refspec %s does not match any.", rs->src);
+			return error("src refspec %s does not match any.", rs->src);
 		break;
 	default:
-		matched_src = NULL;
-		error("src refspec %s matches more than one.", rs->src);
-		break;
+		return error("src refspec %s matches more than one.", rs->src);
 	}
 
-	if (!matched_src)
-		errs = 1;
-
 	if (!dst_value) {
 		unsigned char sha1[20];
 		int flag;
 
-		if (!matched_src)
-			return errs;
 		dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
 		if (!dst_value ||
 		    ((flag & REF_ISSYMREF) &&
@@ -903,18 +985,16 @@ static int match_explicit(struct ref *src, struct ref *dst,
 		      dst_value);
 		break;
 	}
-	if (errs || !matched_dst)
-		return 1;
-	if (matched_dst->peer_ref) {
-		errs = 1;
-		error("dst ref %s receives from more than one src.",
+	if (!matched_dst)
+		return -1;
+	if (matched_dst->peer_ref)
+		return error("dst ref %s receives from more than one src.",
 		      matched_dst->name);
-	}
 	else {
 		matched_dst->peer_ref = matched_src;
 		matched_dst->force = rs->force;
 	}
-	return errs;
+	return 0;
 }
 
 static int match_explicit_refs(struct ref *src, struct ref *dst,
@@ -923,8 +1003,8 @@ static int match_explicit_refs(struct ref *src, struct ref *dst,
 {
 	int i, errs;
 	for (i = errs = 0; i < rs_nr; i++)
-		errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
-	return -errs;
+		errs += match_explicit(src, dst, dst_tail, &rs[i]);
+	return errs;
 }
 
 static const struct refspec *check_pattern_match(const struct refspec *rs,
@@ -932,13 +1012,21 @@ static const struct refspec *check_pattern_match(const struct refspec *rs,
 						 const struct ref *src)
 {
 	int i;
+	int matching_refs = -1;
 	for (i = 0; i < rs_nr; i++) {
-		if (rs[i].pattern &&
-		    !prefixcmp(src->name, rs[i].src) &&
-		    src->name[strlen(rs[i].src)] == '/')
+		if (rs[i].matching &&
+		    (matching_refs == -1 || rs[i].force)) {
+			matching_refs = i;
+			continue;
+		}
+
+		if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
 			return rs + i;
 	}
-	return NULL;
+	if (matching_refs != -1)
+		return rs + matching_refs;
+	else
+		return NULL;
 }
 
 /*
@@ -949,11 +1037,16 @@ static const struct refspec *check_pattern_match(const struct refspec *rs,
 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 	       int nr_refspec, const char **refspec, int flags)
 {
-	struct refspec *rs =
-		parse_push_refspec(nr_refspec, (const char **) refspec);
+	struct refspec *rs;
 	int send_all = flags & MATCH_REFS_ALL;
 	int send_mirror = flags & MATCH_REFS_MIRROR;
+	static const char *default_refspec[] = { ":", 0 };
 
+	if (!nr_refspec) {
+		nr_refspec = 1;
+		refspec = default_refspec;
+	}
+	rs = parse_push_refspec(nr_refspec, (const char **) refspec);
 	if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
 		return -1;
 
@@ -964,48 +1057,50 @@ int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 		char *dst_name;
 		if (src->peer_ref)
 			continue;
-		if (nr_refspec) {
-			pat = check_pattern_match(rs, nr_refspec, src);
-			if (!pat)
-				continue;
-		}
-		else if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
+
+		pat = check_pattern_match(rs, nr_refspec, src);
+		if (!pat)
+			continue;
+
+		if (pat->matching) {
 			/*
 			 * "matching refs"; traditionally we pushed everything
 			 * including refs outside refs/heads/ hierarchy, but
 			 * that does not make much sense these days.
 			 */
-			continue;
+			if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
+				continue;
+			dst_name = xstrdup(src->name);
 
-		if (pat) {
+		} else {
 			const char *dst_side = pat->dst ? pat->dst : pat->src;
 			dst_name = xmalloc(strlen(dst_side) +
 					   strlen(src->name) -
 					   strlen(pat->src) + 2);
 			strcpy(dst_name, dst_side);
 			strcat(dst_name, src->name + strlen(pat->src));
-		} else
-			dst_name = xstrdup(src->name);
+		}
 		dst_peer = find_ref_by_name(dst, dst_name);
-		if (dst_peer && dst_peer->peer_ref)
-			/* We're already sending something to this ref. */
-			goto free_name;
+		if (dst_peer) {
+			if (dst_peer->peer_ref)
+				/* We're already sending something to this ref. */
+				goto free_name;
+
+		} else {
+			if (pat->matching && !(send_all || send_mirror))
+				/*
+				 * Remote doesn't have it, and we have no
+				 * explicit pattern, and we don't have
+				 * --all nor --mirror.
+				 */
+				goto free_name;
 
-		if (!dst_peer && !nr_refspec && !(send_all || send_mirror))
-			/*
-			 * Remote doesn't have it, and we have no
-			 * explicit pattern, and we don't have
-			 * --all nor --mirror.
-			 */
-			goto free_name;
-		if (!dst_peer) {
 			/* Create a new one and link it */
 			dst_peer = make_linked_ref(dst_name, dst_tail);
 			hashcpy(dst_peer->new_sha1, src->new_sha1);
 		}
 		dst_peer->peer_ref = src;
-		if (pat)
-			dst_peer->force = pat->force;
+		dst_peer->force = pat->force;
 	free_name:
 		free(dst_name);
 	}
@@ -1070,10 +1165,8 @@ static struct ref *get_expanded_map(const struct ref *remote_refs,
 			struct ref *cpy = copy_ref(ref);
 			match = ref->name + remote_prefix_len;
 
-			cpy->peer_ref = alloc_ref(local_prefix_len +
-						  strlen(match) + 1);
-			sprintf(cpy->peer_ref->name, "%s%s",
-				refspec->dst, match);
+			cpy->peer_ref = alloc_ref_with_prefix(refspec->dst,
+					local_prefix_len, match);
 			if (refspec->force)
 				cpy->peer_ref->force = 1;
 			*tail = cpy;
@@ -1106,27 +1199,18 @@ struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
 
 static struct ref *get_local_ref(const char *name)
 {
-	struct ref *ret;
 	if (!name)
 		return NULL;
 
-	if (!prefixcmp(name, "refs/")) {
-		ret = alloc_ref(strlen(name) + 1);
-		strcpy(ret->name, name);
-		return ret;
-	}
+	if (!prefixcmp(name, "refs/"))
+		return alloc_ref(name);
 
 	if (!prefixcmp(name, "heads/") ||
 	    !prefixcmp(name, "tags/") ||
-	    !prefixcmp(name, "remotes/")) {
-		ret = alloc_ref(strlen(name) + 6);
-		sprintf(ret->name, "refs/%s", name);
-		return ret;
-	}
+	    !prefixcmp(name, "remotes/"))
+		return alloc_ref_with_prefix("refs/", 5, name);
 
-	ret = alloc_ref(strlen(name) + 12);
-	sprintf(ret->name, "refs/heads/%s", name);
-	return ret;
+	return alloc_ref_with_prefix("refs/heads/", 11, name);
 }
 
 int get_fetch_map(const struct ref *remote_refs,
@@ -1172,3 +1256,123 @@ int get_fetch_map(const struct ref *remote_refs,
 
 	return 0;
 }
+
+int resolve_remote_symref(struct ref *ref, struct ref *list)
+{
+	if (!ref->symref)
+		return 0;
+	for (; list; list = list->next)
+		if (!strcmp(ref->symref, list->name)) {
+			hashcpy(ref->old_sha1, list->old_sha1);
+			return 0;
+		}
+	return 1;
+}
+
+/*
+ * Return true if there is anything to report, otherwise false.
+ */
+int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
+{
+	unsigned char sha1[20];
+	struct commit *ours, *theirs;
+	char symmetric[84];
+	struct rev_info revs;
+	const char *rev_argv[10], *base;
+	int rev_argc;
+
+	/*
+	 * Nothing to report unless we are marked to build on top of
+	 * somebody else.
+	 */
+	if (!branch ||
+	    !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
+		return 0;
+
+	/*
+	 * If what we used to build on no longer exists, there is
+	 * nothing to report.
+	 */
+	base = branch->merge[0]->dst;
+	if (!resolve_ref(base, sha1, 1, NULL))
+		return 0;
+	theirs = lookup_commit(sha1);
+	if (!theirs)
+		return 0;
+
+	if (!resolve_ref(branch->refname, sha1, 1, NULL))
+		return 0;
+	ours = lookup_commit(sha1);
+	if (!ours)
+		return 0;
+
+	/* are we the same? */
+	if (theirs == ours)
+		return 0;
+
+	/* Run "rev-list --left-right ours...theirs" internally... */
+	rev_argc = 0;
+	rev_argv[rev_argc++] = NULL;
+	rev_argv[rev_argc++] = "--left-right";
+	rev_argv[rev_argc++] = symmetric;
+	rev_argv[rev_argc++] = "--";
+	rev_argv[rev_argc] = NULL;
+
+	strcpy(symmetric, sha1_to_hex(ours->object.sha1));
+	strcpy(symmetric + 40, "...");
+	strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
+
+	init_revisions(&revs, NULL);
+	setup_revisions(rev_argc, rev_argv, &revs, NULL);
+	prepare_revision_walk(&revs);
+
+	/* ... and count the commits on each side. */
+	*num_ours = 0;
+	*num_theirs = 0;
+	while (1) {
+		struct commit *c = get_revision(&revs);
+		if (!c)
+			break;
+		if (c->object.flags & SYMMETRIC_LEFT)
+			(*num_ours)++;
+		else
+			(*num_theirs)++;
+	}
+
+	/* clear object flags smudged by the above traversal */
+	clear_commit_marks(ours, ALL_REV_FLAGS);
+	clear_commit_marks(theirs, ALL_REV_FLAGS);
+	return 1;
+}
+
+/*
+ * Return true when there is anything to report, otherwise false.
+ */
+int format_tracking_info(struct branch *branch, struct strbuf *sb)
+{
+	int num_ours, num_theirs;
+	const char *base;
+
+	if (!stat_tracking_info(branch, &num_ours, &num_theirs))
+		return 0;
+
+	base = branch->merge[0]->dst;
+	if (!prefixcmp(base, "refs/remotes/")) {
+		base += strlen("refs/remotes/");
+	}
+	if (!num_theirs)
+		strbuf_addf(sb, "Your branch is ahead of '%s' "
+			    "by %d commit%s.\n",
+			    base, num_ours, (num_ours == 1) ? "" : "s");
+	else if (!num_ours)
+		strbuf_addf(sb, "Your branch is behind '%s' "
+			    "by %d commit%s, "
+			    "and can be fast-forwarded.\n",
+			    base, num_theirs, (num_theirs == 1) ? "" : "s");
+	else
+		strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
+			    "and have %d and %d different commit(s) each, "
+			    "respectively.\n",
+			    base, num_ours, num_theirs);
+	return 1;
+}