1 files changed, 265 insertions, 98 deletions

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 0559fcc871..261b610d24 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1,4 +1,4 @@
-#include "cache.h"
+#include "builtin.h"
 #include "pack.h"
 #include "refs.h"
 #include "pkt-line.h"
@@ -9,6 +9,9 @@
 #include "object.h"
 #include "remote.h"
 #include "transport.h"
+#include "string-list.h"
+#include "sha1-array.h"
+#include "connected.h"
 
 static const char receive_pack_usage[] = "git receive-pack <git-dir>";
 
@@ -16,14 +19,15 @@ enum deny_action {
 	DENY_UNCONFIGURED,
 	DENY_IGNORE,
 	DENY_WARN,
-	DENY_REFUSE,
+	DENY_REFUSE
 };
 
 static int deny_deletes;
 static int deny_non_fast_forwards;
 static enum deny_action deny_current_branch = DENY_UNCONFIGURED;
 static enum deny_action deny_delete_current = DENY_UNCONFIGURED;
-static int receive_fsck_objects;
+static int receive_fsck_objects = -1;
+static int transfer_fsck_objects = -1;
 static int receive_unpack_limit = -1;
 static int transfer_unpack_limit = -1;
 static int unpack_limit = 100;
@@ -77,6 +81,11 @@ static int receive_pack_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (strcmp(var, "transfer.fsckobjects") == 0) {
+		transfer_fsck_objects = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp(var, "receive.denycurrentbranch")) {
 		deny_current_branch = parse_deny_action(var, value);
 		return 0;
@@ -118,9 +127,25 @@ static int show_ref(const char *path, const unsigned char *sha1, int flag, void
 	return 0;
 }
 
+static int show_ref_cb(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	path = strip_namespace(path);
+	/*
+	 * Advertise refs outside our current namespace as ".have"
+	 * refs, so that the client can use them to minimize data
+	 * transfer but will otherwise ignore them. This happens to
+	 * cover ".have" that are thrown in by add_one_alternate_ref()
+	 * to mark histories that are complete in our alternates as
+	 * well.
+	 */
+	if (!path)
+		path = ".have";
+	return show_ref(path, sha1, flag, cb_data);
+}
+
 static void write_head_info(void)
 {
-	for_each_ref(show_ref, NULL);
+	for_each_ref(show_ref_cb, NULL);
 	if (!sent_capabilities)
 		show_ref("capabilities^{}", null_sha1, 0, NULL);
 
@@ -129,13 +154,13 @@ static void write_head_info(void)
 struct command {
 	struct command *next;
 	const char *error_string;
+	unsigned int skip_update:1,
+		     did_not_exist:1;
 	unsigned char old_sha1[20];
 	unsigned char new_sha1[20];
 	char ref_name[FLEX_ARRAY]; /* more */
 };
 
-static struct command *commands;
-
 static const char pre_receive_hook[] = "hooks/pre-receive";
 static const char post_receive_hook[] = "hooks/post-receive";
 
@@ -188,21 +213,15 @@ static int copy_to_sideband(int in, int out, void *arg)
 	return 0;
 }
 
-static int run_receive_hook(const char *hook_name)
+typedef int (*feed_fn)(void *, const char **, size_t *);
+static int run_and_feed_hook(const char *hook_name, feed_fn feed, void *feed_state)
 {
-	static char buf[sizeof(commands->old_sha1) * 2 + PATH_MAX + 4];
-	struct command *cmd;
 	struct child_process proc;
 	struct async muxer;
 	const char *argv[2];
-	int have_input = 0, code;
-
-	for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
-		if (!cmd->error_string)
-			have_input = 1;
-	}
+	int code;
 
-	if (!have_input || access(hook_name, X_OK) < 0)
+	if (access(hook_name, X_OK) < 0)
 		return 0;
 
 	argv[0] = hook_name;
@@ -230,15 +249,13 @@ static int run_receive_hook(const char *hook_name)
 		return code;
 	}
 
-	for (cmd = commands; cmd; cmd = cmd->next) {
-		if (!cmd->error_string) {
-			size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
-				sha1_to_hex(cmd->old_sha1),
-				sha1_to_hex(cmd->new_sha1),
-				cmd->ref_name);
-			if (write_in_full(proc.in, buf, n) != n)
-				break;
-		}
+	while (1) {
+		const char *buf;
+		size_t n;
+		if (feed(feed_state, &buf, &n))
+			break;
+		if (write_in_full(proc.in, buf, n) != n)
+			break;
 	}
 	close(proc.in);
 	if (use_sideband)
@@ -246,6 +263,51 @@ static int run_receive_hook(const char *hook_name)
 	return finish_command(&proc);
 }
 
+struct receive_hook_feed_state {
+	struct command *cmd;
+	int skip_broken;
+	struct strbuf buf;
+};
+
+static int feed_receive_hook(void *state_, const char **bufp, size_t *sizep)
+{
+	struct receive_hook_feed_state *state = state_;
+	struct command *cmd = state->cmd;
+
+	while (cmd &&
+	       state->skip_broken && (cmd->error_string || cmd->did_not_exist))
+		cmd = cmd->next;
+	if (!cmd)
+		return -1; /* EOF */
+	strbuf_reset(&state->buf);
+	strbuf_addf(&state->buf, "%s %s %s\n",
+		    sha1_to_hex(cmd->old_sha1), sha1_to_hex(cmd->new_sha1),
+		    cmd->ref_name);
+	state->cmd = cmd->next;
+	if (bufp) {
+		*bufp = state->buf.buf;
+		*sizep = state->buf.len;
+	}
+	return 0;
+}
+
+static int run_receive_hook(struct command *commands, const char *hook_name,
+			    int skip_broken)
+{
+	struct receive_hook_feed_state state;
+	int status;
+
+	strbuf_init(&state.buf, 0);
+	state.cmd = commands;
+	state.skip_broken = skip_broken;
+	if (feed_receive_hook(&state, NULL, NULL))
+		return 0;
+	state.cmd = commands;
+	status = run_and_feed_hook(hook_name, feed_receive_hook, &state);
+	strbuf_release(&state.buf);
+	return status;
+}
+
 static int run_update_hook(struct command *cmd)
 {
 	static const char update_hook[] = "hooks/update";
@@ -332,17 +394,22 @@ static void refuse_unconfigured_deny_delete_current(void)
 static const char *update(struct command *cmd)
 {
 	const char *name = cmd->ref_name;
+	struct strbuf namespaced_name_buf = STRBUF_INIT;
+	const char *namespaced_name;
 	unsigned char *old_sha1 = cmd->old_sha1;
 	unsigned char *new_sha1 = cmd->new_sha1;
 	struct ref_lock *lock;
 
 	/* only refs/... are allowed */
-	if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
+	if (prefixcmp(name, "refs/") || check_refname_format(name + 5, 0)) {
 		rp_error("refusing to create funny ref '%s' remotely", name);
 		return "funny refname";
 	}
 
-	if (is_ref_checked_out(name)) {
+	strbuf_addf(&namespaced_name_buf, "%s%s", get_git_namespace(), name);
+	namespaced_name = strbuf_detach(&namespaced_name_buf, NULL);
+
+	if (is_ref_checked_out(namespaced_name)) {
 		switch (deny_current_branch) {
 		case DENY_IGNORE:
 			break;
@@ -370,7 +437,7 @@ static const char *update(struct command *cmd)
 			return "deletion prohibited";
 		}
 
-		if (!strcmp(name, head_name)) {
+		if (!strcmp(namespaced_name, head_name)) {
 			switch (deny_delete_current) {
 			case DENY_IGNORE:
 				break;
@@ -423,17 +490,22 @@ static const char *update(struct command *cmd)
 
 	if (is_null_sha1(new_sha1)) {
 		if (!parse_object(old_sha1)) {
-			rp_warning("Allowing deletion of corrupt ref.");
 			old_sha1 = NULL;
+			if (ref_exists(name)) {
+				rp_warning("Allowing deletion of corrupt ref.");
+			} else {
+				rp_warning("Deleting a non-existent ref.");
+				cmd->did_not_exist = 1;
+			}
 		}
-		if (delete_ref(name, old_sha1, 0)) {
+		if (delete_ref(namespaced_name, old_sha1, 0)) {
 			rp_error("failed to delete %s", name);
 			return "failed to delete";
 		}
 		return NULL; /* good */
 	}
 	else {
-		lock = lock_any_ref_for_update(name, old_sha1, 0);
+		lock = lock_any_ref_for_update(namespaced_name, old_sha1, 0);
 		if (!lock) {
 			rp_error("failed to lock %s", name);
 			return "failed to lock";
@@ -447,15 +519,15 @@ static const char *update(struct command *cmd)
 
 static char update_post_hook[] = "hooks/post-update";
 
-static void run_update_post_hook(struct command *cmd)
+static void run_update_post_hook(struct command *commands)
 {
-	struct command *cmd_p;
+	struct command *cmd;
 	int argc;
 	const char **argv;
 	struct child_process proc;
 
-	for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
-		if (cmd_p->error_string)
+	for (argc = 0, cmd = commands; cmd; cmd = cmd->next) {
+		if (cmd->error_string || cmd->did_not_exist)
 			continue;
 		argc++;
 	}
@@ -464,12 +536,12 @@ static void run_update_post_hook(struct command *cmd)
 	argv = xmalloc(sizeof(*argv) * (2 + argc));
 	argv[0] = update_post_hook;
 
-	for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
+	for (argc = 1, cmd = commands; cmd; cmd = cmd->next) {
 		char *p;
-		if (cmd_p->error_string)
+		if (cmd->error_string || cmd->did_not_exist)
 			continue;
-		p = xmalloc(strlen(cmd_p->ref_name) + 1);
-		strcpy(p, cmd_p->ref_name);
+		p = xmalloc(strlen(cmd->ref_name) + 1);
+		strcpy(p, cmd->ref_name);
 		argv[argc] = p;
 		argc++;
 	}
@@ -488,37 +560,146 @@ static void run_update_post_hook(struct command *cmd)
 	}
 }
 
-static void execute_commands(const char *unpacker_error)
+static void check_aliased_update(struct command *cmd, struct string_list *list)
 {
-	struct command *cmd = commands;
+	struct strbuf buf = STRBUF_INIT;
+	const char *dst_name;
+	struct string_list_item *item;
+	struct command *dst_cmd;
+	unsigned char sha1[20];
+	char cmd_oldh[41], cmd_newh[41], dst_oldh[41], dst_newh[41];
+	int flag;
+
+	strbuf_addf(&buf, "%s%s", get_git_namespace(), cmd->ref_name);
+	dst_name = resolve_ref(buf.buf, sha1, 0, &flag);
+	strbuf_release(&buf);
+
+	if (!(flag & REF_ISSYMREF))
+		return;
+
+	dst_name = strip_namespace(dst_name);
+	if (!dst_name) {
+		rp_error("refusing update to broken symref '%s'", cmd->ref_name);
+		cmd->skip_update = 1;
+		cmd->error_string = "broken symref";
+		return;
+	}
+
+	if ((item = string_list_lookup(list, dst_name)) == NULL)
+		return;
+
+	cmd->skip_update = 1;
+
+	dst_cmd = (struct command *) item->util;
+
+	if (!hashcmp(cmd->old_sha1, dst_cmd->old_sha1) &&
+	    !hashcmp(cmd->new_sha1, dst_cmd->new_sha1))
+		return;
+
+	dst_cmd->skip_update = 1;
+
+	strcpy(cmd_oldh, find_unique_abbrev(cmd->old_sha1, DEFAULT_ABBREV));
+	strcpy(cmd_newh, find_unique_abbrev(cmd->new_sha1, DEFAULT_ABBREV));
+	strcpy(dst_oldh, find_unique_abbrev(dst_cmd->old_sha1, DEFAULT_ABBREV));
+	strcpy(dst_newh, find_unique_abbrev(dst_cmd->new_sha1, DEFAULT_ABBREV));
+	rp_error("refusing inconsistent update between symref '%s' (%s..%s) and"
+		 " its target '%s' (%s..%s)",
+		 cmd->ref_name, cmd_oldh, cmd_newh,
+		 dst_cmd->ref_name, dst_oldh, dst_newh);
+
+	cmd->error_string = dst_cmd->error_string =
+		"inconsistent aliased update";
+}
+
+static void check_aliased_updates(struct command *commands)
+{
+	struct command *cmd;
+	struct string_list ref_list = STRING_LIST_INIT_NODUP;
+
+	for (cmd = commands; cmd; cmd = cmd->next) {
+		struct string_list_item *item =
+			string_list_append(&ref_list, cmd->ref_name);
+		item->util = (void *)cmd;
+	}
+	sort_string_list(&ref_list);
+
+	for (cmd = commands; cmd; cmd = cmd->next)
+		check_aliased_update(cmd, &ref_list);
+
+	string_list_clear(&ref_list, 0);
+}
+
+static int command_singleton_iterator(void *cb_data, unsigned char sha1[20])
+{
+	struct command **cmd_list = cb_data;
+	struct command *cmd = *cmd_list;
+
+	if (!cmd)
+		return -1; /* end of list */
+	*cmd_list = NULL; /* this returns only one */
+	hashcpy(sha1, cmd->new_sha1);
+	return 0;
+}
+
+static void set_connectivity_errors(struct command *commands)
+{
+	struct command *cmd;
+
+	for (cmd = commands; cmd; cmd = cmd->next) {
+		struct command *singleton = cmd;
+		if (!check_everything_connected(command_singleton_iterator,
+						0, &singleton))
+			continue;
+		cmd->error_string = "missing necessary objects";
+	}
+}
+
+static int iterate_receive_command_list(void *cb_data, unsigned char sha1[20])
+{
+	struct command **cmd_list = cb_data;
+	struct command *cmd = *cmd_list;
+
+	if (!cmd)
+		return -1; /* end of list */
+	*cmd_list = cmd->next;
+	hashcpy(sha1, cmd->new_sha1);
+	return 0;
+}
+
+static void execute_commands(struct command *commands, const char *unpacker_error)
+{
+	struct command *cmd;
 	unsigned char sha1[20];
 
 	if (unpacker_error) {
-		while (cmd) {
+		for (cmd = commands; cmd; cmd = cmd->next)
 			cmd->error_string = "n/a (unpacker error)";
-			cmd = cmd->next;
-		}
 		return;
 	}
 
-	if (run_receive_hook(pre_receive_hook)) {
-		while (cmd) {
+	cmd = commands;
+	if (check_everything_connected(iterate_receive_command_list,
+				       0, &cmd))
+		set_connectivity_errors(commands);
+
+	if (run_receive_hook(commands, pre_receive_hook, 0)) {
+		for (cmd = commands; cmd; cmd = cmd->next)
 			cmd->error_string = "pre-receive hook declined";
-			cmd = cmd->next;
-		}
 		return;
 	}
 
+	check_aliased_updates(commands);
+
 	head_name = resolve_ref("HEAD", sha1, 0, NULL);
 
-	while (cmd) {
-		cmd->error_string = update(cmd);
-		cmd = cmd->next;
-	}
+	for (cmd = commands; cmd; cmd = cmd->next)
+		if (!cmd->skip_update)
+			cmd->error_string = update(cmd);
 }
 
-static void read_head_info(void)
+static struct command *read_head_info(void)
 {
+	struct command *commands = NULL;
 	struct command **p = &commands;
 	for (;;) {
 		static char line[1000];
@@ -548,15 +729,14 @@ static void read_head_info(void)
 			if (strstr(refname + reflen + 1, "side-band-64k"))
 				use_sideband = LARGE_PACKET_MAX;
 		}
-		cmd = xmalloc(sizeof(struct command) + len - 80);
+		cmd = xcalloc(1, sizeof(struct command) + len - 80);
 		hashcpy(cmd->old_sha1, old_sha1);
 		hashcpy(cmd->new_sha1, new_sha1);
 		memcpy(cmd->ref_name, line + 82, len - 81);
-		cmd->error_string = NULL;
-		cmd->next = NULL;
 		*p = cmd;
 		p = &cmd->next;
 	}
+	return commands;
 }
 
 static const char *parse_pack_header(struct pack_header *hdr)
@@ -586,6 +766,11 @@ static const char *unpack(void)
 	struct pack_header hdr;
 	const char *hdr_err;
 	char hdr_arg[38];
+	int fsck_objects = (receive_fsck_objects >= 0
+			    ? receive_fsck_objects
+			    : transfer_fsck_objects >= 0
+			    ? transfer_fsck_objects
+			    : 0);
 
 	hdr_err = parse_pack_header(&hdr);
 	if (hdr_err)
@@ -598,7 +783,7 @@ static const char *unpack(void)
 		int code, i = 0;
 		const char *unpacker[4];
 		unpacker[i++] = "unpack-objects";
-		if (receive_fsck_objects)
+		if (fsck_objects)
 			unpacker[i++] = "--strict";
 		unpacker[i++] = hdr_arg;
 		unpacker[i++] = NULL;
@@ -618,7 +803,7 @@ static const char *unpack(void)
 
 		keeper[i++] = "index-pack";
 		keeper[i++] = "--stdin";
-		if (receive_fsck_objects)
+		if (fsck_objects)
 			keeper[i++] = "--strict";
 		keeper[i++] = "--fix-thin";
 		keeper[i++] = hdr_arg;
@@ -643,7 +828,7 @@ static const char *unpack(void)
 	}
 }
 
-static void report(const char *unpack_status)
+static void report(struct command *commands, const char *unpack_status)
 {
 	struct command *cmd;
 	struct strbuf buf = STRBUF_INIT;
@@ -667,53 +852,33 @@ static void report(const char *unpack_status)
 	strbuf_release(&buf);
 }
 
-static int delete_only(struct command *cmd)
+static int delete_only(struct command *commands)
 {
-	while (cmd) {
+	struct command *cmd;
+	for (cmd = commands; cmd; cmd = cmd->next) {
 		if (!is_null_sha1(cmd->new_sha1))
 			return 0;
-		cmd = cmd->next;
 	}
 	return 1;
 }
 
-static int add_refs_from_alternate(struct alternate_object_database *e, void *unused)
+static void add_one_alternate_sha1(const unsigned char sha1[20], void *unused)
 {
-	char *other;
-	size_t len;
-	struct remote *remote;
-	struct transport *transport;
-	const struct ref *extra;
-
-	e->name[-1] = '\0';
-	other = xstrdup(make_absolute_path(e->base));
-	e->name[-1] = '/';
-	len = strlen(other);
+	add_extra_ref(".have", sha1, 0);
+}
 
-	while (other[len-1] == '/')
-		other[--len] = '\0';
-	if (len < 8 || memcmp(other + len - 8, "/objects", 8))
-		return 0;
-	/* Is this a git repository with refs? */
-	memcpy(other + len - 8, "/refs", 6);
-	if (!is_directory(other))
-		return 0;
-	other[len - 8] = '\0';
-	remote = remote_get(other);
-	transport = transport_get(remote, other);
-	for (extra = transport_get_remote_refs(transport);
-	     extra;
-	     extra = extra->next) {
-		add_extra_ref(".have", extra->old_sha1, 0);
-	}
-	transport_disconnect(transport);
-	free(other);
-	return 0;
+static void collect_one_alternate_ref(const struct ref *ref, void *data)
+{
+	struct sha1_array *sa = data;
+	sha1_array_append(sa, ref->old_sha1);
 }
 
 static void add_alternate_refs(void)
 {
-	foreach_alt_odb(add_refs_from_alternate, NULL);
+	struct sha1_array sa = SHA1_ARRAY_INIT;
+	for_each_alternate_ref(collect_one_alternate_ref, &sa);
+	sha1_array_for_each_unique(&sa, add_one_alternate_sha1, NULL);
+	sha1_array_clear(&sa);
 }
 
 int cmd_receive_pack(int argc, const char **argv, const char *prefix)
@@ -722,6 +887,9 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 	int stateless_rpc = 0;
 	int i;
 	char *dir = NULL;
+	struct command *commands;
+
+	packet_trace_identity("receive-pack");
 
 	argv++;
 	for (i = 1; i < argc; i++) {
@@ -772,18 +940,17 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 	if (advertise_refs)
 		return 0;
 
-	read_head_info();
-	if (commands) {
+	if ((commands = read_head_info()) != NULL) {
 		const char *unpack_status = NULL;
 
 		if (!delete_only(commands))
 			unpack_status = unpack();
-		execute_commands(unpack_status);
+		execute_commands(commands, unpack_status);
 		if (pack_lockfile)
 			unlink_or_warn(pack_lockfile);
 		if (report_status)
-			report(unpack_status);
-		run_receive_hook(post_receive_hook);
+			report(commands, unpack_status);
+		run_receive_hook(commands, post_receive_hook, 1);
 		run_update_post_hook(commands);
 		if (auto_gc) {
 			const char *argv_gc_auto[] = {