1 files changed, 167 insertions, 32 deletions

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 5fb6d6bcf1..5694a3a27f 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -1,7 +1,10 @@
 /*
  * "git fetch"
  */
+
 #define USE_THE_REPOSITORY_VARIABLE
+#define DISABLE_SIGN_COMPARE_WARNINGS
+
 #include "builtin.h"
 #include "advice.h"
 #include "config.h"
@@ -454,14 +457,10 @@ static void filter_prefetch_refspec(struct refspec *rs)
 				 ref_namespace[NAMESPACE_TAGS].ref))) {
 			int j;
 
-			free(rs->items[i].src);
-			free(rs->items[i].dst);
-			free(rs->raw[i]);
+			refspec_item_clear(&rs->items[i]);
 
-			for (j = i + 1; j < rs->nr; j++) {
+			for (j = i + 1; j < rs->nr; j++)
 				rs->items[j - 1] = rs->items[j];
-				rs->raw[j - 1] = rs->raw[j];
-			}
 			rs->nr--;
 			i--;
 			continue;
@@ -587,7 +586,7 @@ static struct ref *get_ref_map(struct remote *remote,
 		struct refspec_item tag_refspec;
 
 		/* also fetch all tags */
-		refspec_item_init(&tag_refspec, TAG_REFSPEC, 0);
+		refspec_item_init_push(&tag_refspec, TAG_REFSPEC);
 		get_fetch_map(remote_refs, &tag_refspec, &tail, 0);
 		refspec_item_clear(&tag_refspec);
 	} else if (tags == TAGS_DEFAULT && *autotags) {
@@ -669,7 +668,7 @@ static int s_update_ref(const char *action,
 	 */
 	if (!transaction) {
 		transaction = our_transaction = ref_store_transaction_begin(get_main_ref_store(the_repository),
-									    &err);
+									    0, &err);
 		if (!transaction) {
 			ret = STORE_REF_ERROR_OTHER;
 			goto out;
@@ -1578,6 +1577,135 @@ static int backfill_tags(struct display_state *display_state,
 	return retcode;
 }
 
+static const char *strip_refshead(const char *name){
+	skip_prefix(name, "refs/heads/", &name);
+	return name;
+}
+
+static void set_head_advice_msg(const char *remote, const char *head_name)
+{
+	const char message_advice_set_head[] =
+	N_("Run 'git remote set-head %s %s' to follow the change, or set\n"
+	   "'remote.%s.followRemoteHEAD' configuration option to a different value\n"
+	   "if you do not want to see this message. Specifically running\n"
+	   "'git config set remote.%s.followRemoteHEAD warn-if-not-branch-%s'\n"
+	   "will disable the warning until the remote changes HEAD to something else.");
+
+	advise_if_enabled(ADVICE_FETCH_SET_HEAD_WARN, _(message_advice_set_head),
+			remote, head_name, remote, remote, head_name);
+}
+
+static void report_set_head(const char *remote, const char *head_name,
+			struct strbuf *buf_prev, int updateres) {
+	struct strbuf buf_prefix = STRBUF_INIT;
+	const char *prev_head = NULL;
+
+	strbuf_addf(&buf_prefix, "refs/remotes/%s/", remote);
+	skip_prefix(buf_prev->buf, buf_prefix.buf, &prev_head);
+
+	if (prev_head && strcmp(prev_head, head_name)) {
+		printf("'HEAD' at '%s' is '%s', but we have '%s' locally.\n",
+			remote, head_name, prev_head);
+		set_head_advice_msg(remote, head_name);
+	}
+	else if (updateres && buf_prev->len) {
+		printf("'HEAD' at '%s' is '%s', "
+			"but we have a detached HEAD pointing to '%s' locally.\n",
+			remote, head_name, buf_prev->buf);
+		set_head_advice_msg(remote, head_name);
+	}
+	strbuf_release(&buf_prefix);
+}
+
+static int set_head(const struct ref *remote_refs, struct remote *remote)
+{
+	int result = 0, create_only, baremirror, was_detached;
+	struct strbuf b_head = STRBUF_INIT, b_remote_head = STRBUF_INIT,
+		      b_local_head = STRBUF_INIT;
+	int follow_remote_head = remote->follow_remote_head;
+	const char *no_warn_branch = remote->no_warn_branch;
+	char *head_name = NULL;
+	struct ref *ref, *matches;
+	struct ref *fetch_map = NULL, **fetch_map_tail = &fetch_map;
+	struct refspec_item refspec = {
+		.force = 0,
+		.pattern = 1,
+		.src = (char *) "refs/heads/*",
+		.dst = (char *) "refs/heads/*",
+	};
+	struct string_list heads = STRING_LIST_INIT_DUP;
+	struct ref_store *refs = get_main_ref_store(the_repository);
+
+	get_fetch_map(remote_refs, &refspec, &fetch_map_tail, 0);
+	matches = guess_remote_head(find_ref_by_name(remote_refs, "HEAD"),
+				    fetch_map, REMOTE_GUESS_HEAD_ALL);
+	for (ref = matches; ref; ref = ref->next) {
+		string_list_append(&heads, strip_refshead(ref->name));
+	}
+
+	if (follow_remote_head == FOLLOW_REMOTE_NEVER)
+		goto cleanup;
+
+	if (!heads.nr)
+		result = 1;
+	else if (heads.nr > 1)
+		result = 1;
+	else
+		head_name = xstrdup(heads.items[0].string);
+
+	if (!head_name)
+		goto cleanup;
+	baremirror = is_bare_repository() && remote->mirror;
+	create_only = follow_remote_head == FOLLOW_REMOTE_ALWAYS ? 0 : !baremirror;
+	if (baremirror) {
+		strbuf_addstr(&b_head, "HEAD");
+		strbuf_addf(&b_remote_head, "refs/heads/%s", head_name);
+	} else {
+		strbuf_addf(&b_head, "refs/remotes/%s/HEAD", remote->name);
+		strbuf_addf(&b_remote_head, "refs/remotes/%s/%s", remote->name, head_name);
+	}
+		/* make sure it's valid */
+	if (!baremirror && !refs_ref_exists(refs, b_remote_head.buf)) {
+		result = 1;
+		goto cleanup;
+	}
+	was_detached = refs_update_symref_extended(refs, b_head.buf, b_remote_head.buf,
+					"fetch", &b_local_head, create_only);
+	if (was_detached == -1) {
+		result = 1;
+		goto cleanup;
+	}
+	if (verbosity >= 0 &&
+		follow_remote_head == FOLLOW_REMOTE_WARN &&
+		(!no_warn_branch || strcmp(no_warn_branch, head_name)))
+		report_set_head(remote->name, head_name, &b_local_head, was_detached);
+
+cleanup:
+	free(head_name);
+	free_refs(fetch_map);
+	free_refs(matches);
+	string_list_clear(&heads, 0);
+	strbuf_release(&b_head);
+	strbuf_release(&b_local_head);
+	strbuf_release(&b_remote_head);
+	return result;
+}
+
+static int uses_remote_tracking(struct transport *transport, struct refspec *rs)
+{
+	if (!remote_is_configured(transport->remote, 0))
+		return 0;
+
+	if (!rs->nr)
+		rs = &transport->remote->fetch;
+
+	for (int i = 0; i < rs->nr; i++)
+		if (rs->items[i].dst)
+			return 1;
+
+	return 0;
+}
+
 static int do_fetch(struct transport *transport,
 		    struct refspec *rs,
 		    const struct fetch_config *config)
@@ -1590,7 +1718,6 @@ static int do_fetch(struct transport *transport,
 	const struct ref *remote_refs;
 	struct transport_ls_refs_options transport_ls_refs_options =
 		TRANSPORT_LS_REFS_OPTIONS_INIT;
-	int must_list_refs = 1;
 	struct fetch_head fetch_head = { 0 };
 	struct strbuf err = STRBUF_INIT;
 
@@ -1609,21 +1736,7 @@ static int do_fetch(struct transport *transport,
 	}
 
 	if (rs->nr) {
-		int i;
-
 		refspec_ref_prefixes(rs, &transport_ls_refs_options.ref_prefixes);
-
-		/*
-		 * We can avoid listing refs if all of them are exact
-		 * OIDs
-		 */
-		must_list_refs = 0;
-		for (i = 0; i < rs->nr; i++) {
-			if (!rs->items[i].exact_sha1) {
-				must_list_refs = 1;
-				break;
-			}
-		}
 	} else {
 		struct branch *branch = branch_get(NULL);
 
@@ -1638,16 +1751,30 @@ static int do_fetch(struct transport *transport,
 					    branch->merge[i]->src);
 			}
 		}
-	}
 
-	if (tags == TAGS_SET || tags == TAGS_DEFAULT) {
-		must_list_refs = 1;
-		if (transport_ls_refs_options.ref_prefixes.nr)
+		/*
+		 * If there are no refs specified to fetch, then we just
+		 * fetch HEAD; mention that to narrow the advertisement.
+		 */
+		if (!transport_ls_refs_options.ref_prefixes.nr)
 			strvec_push(&transport_ls_refs_options.ref_prefixes,
-				    "refs/tags/");
+				    "HEAD");
 	}
 
-	if (must_list_refs) {
+	if (tags == TAGS_SET || tags == TAGS_DEFAULT)
+		strvec_push(&transport_ls_refs_options.ref_prefixes,
+			    "refs/tags/");
+
+	if (transport_ls_refs_options.ref_prefixes.nr &&
+	    uses_remote_tracking(transport, rs))
+		strvec_push(&transport_ls_refs_options.ref_prefixes,
+			    "HEAD");
+
+	/*
+	 * Only initiate ref listing if we have at least one ref we want to
+	 * know about.
+	 */
+	if (transport_ls_refs_options.ref_prefixes.nr) {
 		trace2_region_enter("fetch", "remote_refs", the_repository);
 		remote_refs = transport_get_remote_refs(transport,
 							&transport_ls_refs_options);
@@ -1671,7 +1798,7 @@ static int do_fetch(struct transport *transport,
 
 	if (atomic_fetch) {
 		transaction = ref_store_transaction_begin(get_main_ref_store(the_repository),
-							  &err);
+							  0, &err);
 		if (!transaction) {
 			retcode = -1;
 			goto cleanup;
@@ -1798,6 +1925,12 @@ static int do_fetch(struct transport *transport,
 				  "you need to specify exactly one branch with the --set-upstream option"));
 		}
 	}
+	if (set_head(remote_refs, transport->remote))
+		;
+		/*
+		 * Way too many cases where this can go wrong
+		 * so let's just fail silently for now.
+		 */
 
 cleanup:
 	if (retcode) {
@@ -1988,6 +2121,8 @@ static int fetch_multiple(struct string_list *list, int max_children,
 	strvec_pushl(&argv, "-c", "fetch.bundleURI=",
 		     "fetch", "--append", "--no-auto-gc",
 		     "--no-write-commit-graph", NULL);
+	for (i = 0; i < server_options.nr; i++)
+		strvec_pushf(&argv, "--server-option=%s", server_options.items[i].string);
 	add_options_to_argv(&argv, config);
 
 	if (max_children != 1 && list->nr != 1) {
@@ -2221,8 +2356,8 @@ int cmd_fetch(int argc,
 			   N_("deepen history of shallow clone")),
 		OPT_STRING(0, "shallow-since", &deepen_since, N_("time"),
 			   N_("deepen history of shallow repository based on time")),
-		OPT_STRING_LIST(0, "shallow-exclude", &deepen_not, N_("revision"),
-				N_("deepen history of shallow clone, excluding rev")),
+		OPT_STRING_LIST(0, "shallow-exclude", &deepen_not, N_("ref"),
+				N_("deepen history of shallow clone, excluding ref")),
 		OPT_INTEGER(0, "deepen", &deepen_relative,
 			    N_("deepen history of shallow clone")),
 		OPT_SET_INT_F(0, "unshallow", &unshallow,