1 files changed, 213 insertions, 39 deletions

diff --git a/remote.c b/remote.c
index efcba931ec..9f1a8aa2c4 100644
--- a/remote.c
+++ b/remote.c
@@ -148,6 +148,7 @@ static struct remote *make_remote(const char *name, int len)
 	}
 
 	ret = xcalloc(1, sizeof(struct remote));
+	ret->prune = -1;  /* unspecified */
 	ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 	remotes[remotes_nr++] = ret;
 	if (len)
@@ -404,6 +405,8 @@ static int handle_config(const char *key, const char *value, void *cb)
 		remote->skip_default_update = git_config_bool(key, value);
 	else if (!strcmp(subkey, ".skipfetchall"))
 		remote->skip_default_update = git_config_bool(key, value);
+	else if (!strcmp(subkey, ".prune"))
+		remote->prune = git_config_bool(key, value);
 	else if (!strcmp(subkey, ".url")) {
 		const char *v;
 		if (git_config_string(&v, key, value))
@@ -480,7 +483,7 @@ static void read_config(void)
 	int flag;
 	if (default_remote_name) /* did this already */
 		return;
-	default_remote_name = xstrdup("origin");
+	default_remote_name = "origin";
 	current_branch = NULL;
 	head_ref = resolve_ref_unsafe("HEAD", sha1, 0, &flag);
 	if (head_ref && (flag & REF_ISSYMREF) &&
@@ -1302,6 +1305,14 @@ static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***ds
 	free(sent_tips.tip);
 }
 
+struct ref *find_ref_by_name(const struct ref *list, const char *name)
+{
+	for ( ; list; list = list->next)
+		if (!strcmp(list->name, name))
+			return (struct ref *)list;
+	return NULL;
+}
+
 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
 {
 	for ( ; ref; ref = ref->next)
@@ -1411,12 +1422,13 @@ int match_push_refs(struct ref *src, struct ref **dst,
 }
 
 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
-	int force_update)
+			     int force_update)
 {
 	struct ref *ref;
 
 	for (ref = remote_refs; ref; ref = ref->next) {
 		int force_ref_update = ref->force || force_update;
+		int reject_reason = 0;
 
 		if (ref->peer_ref)
 			hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
@@ -1431,6 +1443,26 @@ 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.
+		 *
+		 * It also is an error if the user told us to check
+		 * with the remote-tracking branch to find the value
+		 * to expect, but we did not have such a tracking
+		 * branch.
+		 */
+		if (ref->expect_old_sha1) {
+			if (ref->expect_old_no_trackback ||
+			    hashcmp(ref->old_sha1, ref->old_sha1_expect))
+				reject_reason = REF_STATUS_REJECT_STALE;
+		}
+
+		/*
+		 * The usual "must fast-forward" rules.
+		 *
 		 * Decide whether an individual refspec A:B can be
 		 * pushed.  The push will succeed if any of the
 		 * following are true:
@@ -1448,24 +1480,26 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
 		 *     passing the --force argument
 		 */
 
-		if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
-			int why = 0; /* why would this push require --force? */
-
+		else if (!ref->deletion && !is_null_sha1(ref->old_sha1)) {
 			if (!prefixcmp(ref->name, "refs/tags/"))
-				why = REF_STATUS_REJECT_ALREADY_EXISTS;
+				reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
 			else if (!has_sha1_file(ref->old_sha1))
-				why = REF_STATUS_REJECT_FETCH_FIRST;
+				reject_reason = 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;
+				reject_reason = 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;
+				reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
 		}
+
+		/*
+		 * "--force" will defeat any rejection implemented
+		 * by the rules above.
+		 */
+		if (!force_ref_update)
+			ref->status = reject_reason;
+		else if (reject_reason)
+			ref->forced_update = 1;
 	}
 }
 
@@ -1695,7 +1729,11 @@ int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
 }
 
 /*
- * Return true if there is anything to report, otherwise false.
+ * Compare a branch with its upstream, and save their differences (number
+ * of commits) in *num_ours and *num_theirs.
+ *
+ * Return 0 if branch has no upstream (no base), -1 if upstream is missing
+ * (with "gone" base), otherwise 1 (with base).
  */
 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
 {
@@ -1706,34 +1744,30 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
 	const char *rev_argv[10], *base;
 	int rev_argc;
 
-	/*
-	 * Nothing to report unless we are marked to build on top of
-	 * somebody else.
-	 */
+	/* Cannot stat 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.
-	 */
+	/* Cannot stat if what we used to build on no longer exists */
 	base = branch->merge[0]->dst;
 	if (read_ref(base, sha1))
-		return 0;
+		return -1;
 	theirs = lookup_commit_reference(sha1);
 	if (!theirs)
-		return 0;
+		return -1;
 
 	if (read_ref(branch->refname, sha1))
-		return 0;
+		return -1;
 	ours = lookup_commit_reference(sha1);
 	if (!ours)
-		return 0;
+		return -1;
 
 	/* are we the same? */
-	if (theirs == ours)
-		return 0;
+	if (theirs == ours) {
+		*num_theirs = *num_ours = 0;
+		return 1;
+	}
 
 	/* Run "rev-list --left-right ours...theirs" internally... */
 	rev_argc = 0;
@@ -1775,31 +1809,53 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
  */
 int format_tracking_info(struct branch *branch, struct strbuf *sb)
 {
-	int num_ours, num_theirs;
+	int ours, theirs;
 	const char *base;
+	int upstream_is_gone = 0;
 
-	if (!stat_tracking_info(branch, &num_ours, &num_theirs))
+	switch (stat_tracking_info(branch, &ours, &theirs)) {
+	case 0:
+		/* no base */
 		return 0;
+	case -1:
+		/* with "gone" base */
+		upstream_is_gone = 1;
+		break;
+	default:
+		/* with base */
+		break;
+	}
 
 	base = branch->merge[0]->dst;
 	base = shorten_unambiguous_ref(base, 0);
-	if (!num_theirs) {
+	if (upstream_is_gone) {
+		strbuf_addf(sb,
+			_("Your branch is based on '%s', but the upstream is gone.\n"),
+			base);
+		if (advice_status_hints)
+			strbuf_addf(sb,
+				_("  (use \"git branch --unset-upstream\" to fixup)\n"));
+	} else if (!ours && !theirs) {
+		strbuf_addf(sb,
+			_("Your branch is up-to-date with '%s'.\n"),
+			base);
+	} else if (!theirs) {
 		strbuf_addf(sb,
 			Q_("Your branch is ahead of '%s' by %d commit.\n",
 			   "Your branch is ahead of '%s' by %d commits.\n",
-			   num_ours),
-			base, num_ours);
+			   ours),
+			base, ours);
 		if (advice_status_hints)
 			strbuf_addf(sb,
 				_("  (use \"git push\" to publish your local commits)\n"));
-	} else if (!num_ours) {
+	} else if (!ours) {
 		strbuf_addf(sb,
 			Q_("Your branch is behind '%s' by %d commit, "
 			       "and can be fast-forwarded.\n",
 			   "Your branch is behind '%s' by %d commits, "
 			       "and can be fast-forwarded.\n",
-			   num_theirs),
-			base, num_theirs);
+			   theirs),
+			base, theirs);
 		if (advice_status_hints)
 			strbuf_addf(sb,
 				_("  (use \"git pull\" to update your local branch)\n"));
@@ -1811,8 +1867,8 @@ 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",
-			   num_theirs),
-			base, num_ours, num_theirs);
+			   theirs),
+			base, ours, theirs);
 		if (advice_status_hints)
 			strbuf_addf(sb,
 				_("  (use \"git pull\" to merge the remote branch into yours)\n"));
@@ -1936,3 +1992,121 @@ struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fet
 	string_list_clear(&ref_names, 0);
 	return stale_refs;
 }
+
+/*
+ * Compare-and-swap
+ */
+void clear_cas_option(struct push_cas_option *cas)
+{
+	int i;
+
+	for (i = 0; i < cas->nr; i++)
+		free(cas->entry[i].refname);
+	free(cas->entry);
+	memset(cas, 0, sizeof(*cas));
+}
+
+static struct push_cas *add_cas_entry(struct push_cas_option *cas,
+				      const char *refname,
+				      size_t refnamelen)
+{
+	struct push_cas *entry;
+	ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
+	entry = &cas->entry[cas->nr++];
+	memset(entry, 0, sizeof(*entry));
+	entry->refname = xmemdupz(refname, refnamelen);
+	return entry;
+}
+
+int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
+{
+	const char *colon;
+	struct push_cas *entry;
+
+	if (unset) {
+		/* "--no-<option>" */
+		clear_cas_option(cas);
+		return 0;
+	}
+
+	if (!arg) {
+		/* just "--<option>" */
+		cas->use_tracking_for_rest = 1;
+		return 0;
+	}
+
+	/* "--<option>=refname" or "--<option>=refname:value" */
+	colon = strchrnul(arg, ':');
+	entry = add_cas_entry(cas, arg, colon - arg);
+	if (!*colon)
+		entry->use_tracking = 1;
+	else if (get_sha1(colon + 1, entry->expect))
+		return error("cannot parse expected object name '%s'", colon + 1);
+	return 0;
+}
+
+int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
+{
+	return parse_push_cas_option(opt->value, arg, unset);
+}
+
+int is_empty_cas(const struct push_cas_option *cas)
+{
+	return !cas->use_tracking_for_rest && !cas->nr;
+}
+
+/*
+ * Look at remote.fetch refspec and see if we have a remote
+ * tracking branch for the refname there.  Fill its current
+ * value in sha1[].
+ * If we cannot do so, return negative to signal an error.
+ */
+static int remote_tracking(struct remote *remote, const char *refname,
+			   unsigned char sha1[20])
+{
+	char *dst;
+
+	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, sha1))
+		return -1; /* we know what the tracking ref is but we cannot read it */
+	return 0;
+}
+
+static void apply_cas(struct push_cas_option *cas,
+		      struct remote *remote,
+		      struct ref *ref)
+{
+	int i;
+
+	/* Find an explicit --<option>=<name>[:<value>] entry */
+	for (i = 0; i < cas->nr; i++) {
+		struct push_cas *entry = &cas->entry[i];
+		if (!refname_match(entry->refname, ref->name, ref_rev_parse_rules))
+			continue;
+		ref->expect_old_sha1 = 1;
+		if (!entry->use_tracking)
+			hashcpy(ref->old_sha1_expect, cas->entry[i].expect);
+		else if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
+			ref->expect_old_no_trackback = 1;
+		return;
+	}
+
+	/* Are we using "--<option>" to cover all? */
+	if (!cas->use_tracking_for_rest)
+		return;
+
+	ref->expect_old_sha1 = 1;
+	if (remote_tracking(remote, ref->name, ref->old_sha1_expect))
+		ref->expect_old_no_trackback = 1;
+}
+
+void apply_push_cas(struct push_cas_option *cas,
+		    struct remote *remote,
+		    struct ref *remote_refs)
+{
+	struct ref *ref;
+	for (ref = remote_refs; ref; ref = ref->next)
+		apply_cas(cas, remote, ref);
+}