From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 7 Feb 2019 06:05:30 +0000 (-0800)
Subject: Merge branch 'bc/fetch-pack-clear-alternate-shallow'
X-Git-Tag: v2.21.0-rc0~3
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/8f0f46539a8c557985241f3aec7a12bd5f2634c2?ds=inline;hp=-c

Merge branch 'bc/fetch-pack-clear-alternate-shallow'

"git fetch" over protocol v2 that needs to make a second connection
to backfill tags did not clear a variable that holds shallow
repository information correctly, leading to an access of freed
piece of memory.

* bc/fetch-pack-clear-alternate-shallow:
fetch-pack: clear alternate shallow in one more place
fetch-pack: clear alternate shallow when complete
---

8f0f46539a8c557985241f3aec7a12bd5f2634c2
diff --combined fetch-pack.c
index 08b3b356fa,a92621a388..812be15d7e
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@@ -135,42 -135,38 +135,42 @@@ enum ack_type 
  	ACK_ready
  };
  
 -static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 +static void consume_shallow_list(struct fetch_pack_args *args,
 +				 struct packet_reader *reader)
  {
  	if (args->stateless_rpc && args->deepen) {
  		/* If we sent a depth we will get back "duplicate"
  		 * shallow and unshallow commands every time there
  		 * is a block of have lines exchanged.
  		 */
 -		char *line;
 -		while ((line = packet_read_line(fd, NULL))) {
 -			if (starts_with(line, "shallow "))
 +		while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 +			if (starts_with(reader->line, "shallow "))
  				continue;
 -			if (starts_with(line, "unshallow "))
 +			if (starts_with(reader->line, "unshallow "))
  				continue;
  			die(_("git fetch-pack: expected shallow list"));
  		}
 +		if (reader->status != PACKET_READ_FLUSH)
 +			die(_("git fetch-pack: expected a flush packet after shallow list"));
  	}
  }
  
 -static enum ack_type get_ack(int fd, struct object_id *result_oid)
 +static enum ack_type get_ack(struct packet_reader *reader,
 +			     struct object_id *result_oid)
  {
  	int len;
 -	char *line = packet_read_line(fd, &len);
  	const char *arg;
  
 -	if (!line)
 +	if (packet_reader_read(reader) != PACKET_READ_NORMAL)
  		die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 -	if (!strcmp(line, "NAK"))
 +	len = reader->pktlen;
 +
 +	if (!strcmp(reader->line, "NAK"))
  		return NAK;
 -	if (skip_prefix(line, "ACK ", &arg)) {
 +	if (skip_prefix(reader->line, "ACK ", &arg)) {
  		if (!get_oid_hex(arg, result_oid)) {
  			arg += 40;
 -			len -= arg - line;
 +			len -= arg - reader->line;
  			if (len < 1)
  				return ACK;
  			if (strstr(arg, "continue"))
@@@ -182,7 -178,9 +182,7 @@@
  			return ACK;
  		}
  	}
 -	if (skip_prefix(line, "ERR ", &arg))
 -		die(_("remote error: %s"), arg);
 -	die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 +	die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
  }
  
  static void send_request(struct fetch_pack_args *args,
@@@ -250,15 -248,10 +250,15 @@@ static int find_common(struct fetch_neg
  	int got_ready = 0;
  	struct strbuf req_buf = STRBUF_INIT;
  	size_t state_len = 0;
 +	struct packet_reader reader;
  
  	if (args->stateless_rpc && multi_ack == 1)
  		die(_("--stateless-rpc requires multi_ack_detailed"));
  
 +	packet_reader_init(&reader, fd[0], NULL, 0,
 +			   PACKET_READ_CHOMP_NEWLINE |
 +			   PACKET_READ_DIE_ON_ERR_PACKET);
 +
  	if (!args->no_dependents) {
  		mark_tips(negotiator, args->negotiation_tips);
  		for_each_cached_alternate(negotiator, insert_one_alternate_object);
@@@ -336,42 -329,38 +336,42 @@@
  			packet_buf_write(&req_buf, "deepen-not %s", s->string);
  		}
  	}
 -	if (server_supports_filtering && args->filter_options.choice)
 +	if (server_supports_filtering && args->filter_options.choice) {
 +		struct strbuf expanded_filter_spec = STRBUF_INIT;
 +		expand_list_objects_filter_spec(&args->filter_options,
 +						&expanded_filter_spec);
  		packet_buf_write(&req_buf, "filter %s",
 -				 args->filter_options.filter_spec);
 +				 expanded_filter_spec.buf);
 +		strbuf_release(&expanded_filter_spec);
 +	}
  	packet_buf_flush(&req_buf);
  	state_len = req_buf.len;
  
  	if (args->deepen) {
 -		char *line;
  		const char *arg;
  		struct object_id oid;
  
  		send_request(args, fd[1], &req_buf);
 -		while ((line = packet_read_line(fd[0], NULL))) {
 -			if (skip_prefix(line, "shallow ", &arg)) {
 +		while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
 +			if (skip_prefix(reader.line, "shallow ", &arg)) {
  				if (get_oid_hex(arg, &oid))
 -					die(_("invalid shallow line: %s"), line);
 +					die(_("invalid shallow line: %s"), reader.line);
  				register_shallow(the_repository, &oid);
  				continue;
  			}
 -			if (skip_prefix(line, "unshallow ", &arg)) {
 +			if (skip_prefix(reader.line, "unshallow ", &arg)) {
  				if (get_oid_hex(arg, &oid))
 -					die(_("invalid unshallow line: %s"), line);
 +					die(_("invalid unshallow line: %s"), reader.line);
  				if (!lookup_object(the_repository, oid.hash))
 -					die(_("object not found: %s"), line);
 +					die(_("object not found: %s"), reader.line);
  				/* make sure that it is parsed as shallow */
  				if (!parse_object(the_repository, &oid))
 -					die(_("error in object: %s"), line);
 +					die(_("error in object: %s"), reader.line);
  				if (unregister_shallow(&oid))
 -					die(_("no shallow found: %s"), line);
 +					die(_("no shallow found: %s"), reader.line);
  				continue;
  			}
 -			die(_("expected shallow/unshallow, got %s"), line);
 +			die(_("expected shallow/unshallow, got %s"), reader.line);
  		}
  	} else if (!args->stateless_rpc)
  		send_request(args, fd[1], &req_buf);
@@@ -408,9 -397,9 +408,9 @@@
  			if (!args->stateless_rpc && count == INITIAL_FLUSH)
  				continue;
  
 -			consume_shallow_list(args, fd[0]);
 +			consume_shallow_list(args, &reader);
  			do {
 -				ack = get_ack(fd[0], result_oid);
 +				ack = get_ack(&reader, result_oid);
  				if (ack)
  					print_verbose(args, _("got %s %d %s"), "ack",
  						      ack, oid_to_hex(result_oid));
@@@ -480,9 -469,9 +480,9 @@@ done
  	strbuf_release(&req_buf);
  
  	if (!got_ready || !no_done)
 -		consume_shallow_list(args, fd[0]);
 +		consume_shallow_list(args, &reader);
  	while (flushes || multi_ack) {
 -		int ack = get_ack(fd[0], result_oid);
 +		int ack = get_ack(&reader, result_oid);
  		if (ack) {
  			print_verbose(args, _("got %s (%d) %s"), "ack",
  				      ack, oid_to_hex(result_oid));
@@@ -1097,8 -1086,7 +1097,8 @@@ static int add_haves(struct fetch_negot
  static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
  			      const struct fetch_pack_args *args,
  			      const struct ref *wants, struct oidset *common,
 -			      int *haves_to_send, int *in_vain)
 +			      int *haves_to_send, int *in_vain,
 +			      int sideband_all)
  {
  	int ret = 0;
  	struct strbuf req_buf = STRBUF_INIT;
@@@ -1124,8 -1112,6 +1124,8 @@@
  		packet_buf_write(&req_buf, "include-tag");
  	if (prefer_ofs_delta)
  		packet_buf_write(&req_buf, "ofs-delta");
 +	if (sideband_all)
 +		packet_buf_write(&req_buf, "sideband-all");
  
  	/* Add shallow-info and deepen request */
  	if (server_supports_feature("fetch", "shallow", 0))
@@@ -1136,13 -1122,9 +1136,13 @@@
  	/* Add filter */
  	if (server_supports_feature("fetch", "filter", 0) &&
  	    args->filter_options.choice) {
 +		struct strbuf expanded_filter_spec = STRBUF_INIT;
  		print_verbose(args, _("Server supports filter"));
 +		expand_list_objects_filter_spec(&args->filter_options,
 +						&expanded_filter_spec);
  		packet_buf_write(&req_buf, "filter %s",
 -				 args->filter_options.filter_spec);
 +				 expanded_filter_spec.buf);
 +		strbuf_release(&expanded_filter_spec);
  	} else if (args->filter_options.choice) {
  		warning("filtering not recognized by server, ignoring");
  	}
@@@ -1290,6 -1272,8 +1290,8 @@@ static void receive_shallow_info(struc
  		setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
  					NULL);
  		args->deepen = 1;
+ 	} else {
+ 		alternate_shallow_file = NULL;
  	}
  }
  
@@@ -1343,13 -1327,7 +1345,13 @@@ static struct ref *do_fetch_pack_v2(str
  	struct fetch_negotiator negotiator;
  	fetch_negotiator_init(&negotiator, negotiation_algorithm);
  	packet_reader_init(&reader, fd[0], NULL, 0,
 -			   PACKET_READ_CHOMP_NEWLINE);
 +			   PACKET_READ_CHOMP_NEWLINE |
 +			   PACKET_READ_DIE_ON_ERR_PACKET);
 +	if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
 +	    server_supports_feature("fetch", "sideband-all", 0)) {
 +		reader.use_sideband = 1;
 +		reader.me = "fetch-pack";
 +	}
  
  	while (state != FETCH_DONE) {
  		switch (state) {
@@@ -1383,8 -1361,7 +1385,8 @@@
  		case FETCH_SEND_REQUEST:
  			if (send_fetch_request(&negotiator, fd[1], args, ref,
  					       &common,
 -					       &haves_to_send, &in_vain))
 +					       &haves_to_send, &in_vain,
 +					       reader.use_sideband))
  				state = FETCH_GET_PACK;
  			else
  				state = FETCH_PROCESS_ACKS;
@@@ -1514,6 -1491,7 +1516,7 @@@ static void update_shallow(struct fetch
  			rollback_lock_file(&shallow_lock);
  		} else
  			commit_lock_file(&shallow_lock);
+ 		alternate_shallow_file = NULL;
  		return;
  	}
  
@@@ -1537,6 -1515,7 +1540,7 @@@
  						&alternate_shallow_file,
  						&extra);
  			commit_lock_file(&shallow_lock);
+ 			alternate_shallow_file = NULL;
  		}
  		oid_array_clear(&extra);
  		return;
@@@ -1576,6 -1555,7 +1580,7 @@@
  		commit_lock_file(&shallow_lock);
  		oid_array_clear(&extra);
  		oid_array_clear(&ref);
+ 		alternate_shallow_file = NULL;
  		return;
  	}