Merge branch 'jk/pkt-line-cleanup'

Clean up pkt-line API, implementation and its callers to make them
more robust.

* jk/pkt-line-cleanup:
  do not use GIT_TRACE_PACKET=3 in tests
  remote-curl: always parse incoming refs
  remote-curl: move ref-parsing code up in file
  remote-curl: pass buffer straight to get_remote_heads
  teach get_remote_heads to read from a memory buffer
  pkt-line: share buffer/descriptor reading implementation
  pkt-line: provide a LARGE_PACKET_MAX static buffer
  pkt-line: move LARGE_PACKET_MAX definition from sideband
  pkt-line: teach packet_read_line to chomp newlines
  pkt-line: provide a generic reading function with options
  pkt-line: drop safe_write function
  pkt-line: move a misplaced comment
  write_or_die: raise SIGPIPE when we get EPIPE
  upload-archive: use argv_array to store client arguments
  upload-archive: do not copy repo name
  send-pack: prefer prefixcmp over memcmp in receive_status
  fetch-pack: fix out-of-bounds buffer offset in get_ack
  upload-pack: remove packet debugging harness
  upload-pack: do not add duplicate objects to shallow list
  upload-pack: use get_sha1_hex to parse "shallow" lines

22 files changed, 338 insertions, 365 deletions

diff --git a/builtin/archive.c b/builtin/archive.c
index 9a1cfd3dac..49178f159e 100644
--- a/builtin/archive.c
+++ b/builtin/archive.c
@@ -27,8 +27,8 @@ static int run_remote_archiver(int argc, const char **argv,
 			       const char *remote, const char *exec,
 			       const char *name_hint)
 {
-	char buf[LARGE_PACKET_MAX];
-	int fd[2], i, len, rv;
+	char *buf;
+	int fd[2], i, rv;
 	struct transport *transport;
 	struct remote *_remote;
 
@@ -53,21 +53,18 @@ static int run_remote_archiver(int argc, const char **argv,
 		packet_write(fd[1], "argument %s\n", argv[i]);
 	packet_flush(fd[1]);
 
-	len = packet_read_line(fd[0], buf, sizeof(buf));
-	if (!len)
+	buf = packet_read_line(fd[0], NULL);
+	if (!buf)
 		die(_("git archive: expected ACK/NAK, got EOF"));
-	if (buf[len-1] == '\n')
-		buf[--len] = 0;
 	if (strcmp(buf, "ACK")) {
-		if (len > 5 && !prefixcmp(buf, "NACK "))
+		if (!prefixcmp(buf, "NACK "))
 			die(_("git archive: NACK %s"), buf + 5);
-		if (len > 4 && !prefixcmp(buf, "ERR "))
+		if (!prefixcmp(buf, "ERR "))
 			die(_("remote error: %s"), buf + 4);
 		die(_("git archive: protocol error"));
 	}
 
-	len = packet_read_line(fd[0], buf, sizeof(buf));
-	if (len)
+	if (packet_read_line(fd[0], NULL))
 		die(_("git archive: expected a flush"));
 
 	/* Now, start reading from fd[0] and spit it out to stdout */
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 670e81fd99..aba4465552 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -119,14 +119,11 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 			/* in stateless RPC mode we use pkt-line to read
 			 * from stdin, until we get a flush packet
 			 */
-			static char line[1000];
 			for (;;) {
-				int n = packet_read_line(0, line, sizeof(line));
-				if (!n)
+				char *line = packet_read_line(0, NULL);
+				if (!line)
 					break;
-				if (line[n-1] == '\n')
-					n--;
-				add_sought_entry_mem(&sought, &nr_sought,  &alloc_sought, line, n);
+				add_sought_entry(&sought, &nr_sought,  &alloc_sought, line);
 			}
 		}
 		else {
@@ -147,7 +144,7 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 				   args.verbose ? CONNECT_VERBOSE : 0);
 	}
 
-	get_remote_heads(fd[0], &ref, 0, NULL);
+	get_remote_heads(fd[0], NULL, 0, &ref, 0, NULL);
 
 	ref = fetch_pack(&args, fd, conn, ref, dest,
 			 sought, nr_sought, pack_lockfile_ptr);
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 62ba6e7a3d..ccebd74f16 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -754,17 +754,15 @@ static struct command *read_head_info(void)
 	struct command *commands = NULL;
 	struct command **p = &commands;
 	for (;;) {
-		static char line[1000];
+		char *line;
 		unsigned char old_sha1[20], new_sha1[20];
 		struct command *cmd;
 		char *refname;
 		int len, reflen;
 
-		len = packet_read_line(0, line, sizeof(line));
-		if (!len)
+		line = packet_read_line(0, &len);
+		if (!line)
 			break;
-		if (line[len-1] == '\n')
-			line[--len] = 0;
 		if (len < 83 ||
 		    line[40] != ' ' ||
 		    line[81] != ' ' ||
@@ -932,7 +930,7 @@ static void report(struct command *commands, const char *unpack_status)
 	if (use_sideband)
 		send_sideband(1, 1, buf.buf, buf.len, use_sideband);
 	else
-		safe_write(1, buf.buf, buf.len);
+		write_or_die(1, buf.buf, buf.len);
 	strbuf_release(&buf);
 }
 
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index 57a46b2654..152c4ea092 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -79,7 +79,7 @@ static void print_helper_status(struct ref *ref)
 		}
 		strbuf_addch(&buf, '\n');
 
-		safe_write(1, buf.buf, buf.len);
+		write_or_die(1, buf.buf, buf.len);
 	}
 	strbuf_release(&buf);
 }
@@ -207,7 +207,7 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 
 	memset(&extra_have, 0, sizeof(extra_have));
 
-	get_remote_heads(fd[0], &remote_refs, REF_NORMAL, &extra_have);
+	get_remote_heads(fd[0], NULL, 0, &remote_refs, REF_NORMAL, &extra_have);
 
 	transport_verify_remote_names(nr_refspecs, refspecs);
 
diff --git a/builtin/upload-archive.c b/builtin/upload-archive.c
index b928beb8ed..af2da35e7d 100644
--- a/builtin/upload-archive.c
+++ b/builtin/upload-archive.c
@@ -7,6 +7,7 @@
 #include "pkt-line.h"
 #include "sideband.h"
 #include "run-command.h"
+#include "argv-array.h"
 
 static const char upload_archive_usage[] =
 	"git upload-archive <repo>";
@@ -18,51 +19,31 @@ static const char deadchild[] =
 
 int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix)
 {
-	const char *sent_argv[MAX_ARGS];
+	struct argv_array sent_argv = ARGV_ARRAY_INIT;
 	const char *arg_cmd = "argument ";
-	char *p, buf[4096];
-	int sent_argc;
-	int len;
 
 	if (argc != 2)
 		usage(upload_archive_usage);
 
-	if (strlen(argv[1]) + 1 > sizeof(buf))
-		die("insanely long repository name");
-
-	strcpy(buf, argv[1]); /* enter-repo smudges its argument */
-
-	if (!enter_repo(buf, 0))
-		die("'%s' does not appear to be a git repository", buf);
+	if (!enter_repo(argv[1], 0))
+		die("'%s' does not appear to be a git repository", argv[1]);
 
 	/* put received options in sent_argv[] */
-	sent_argc = 1;
-	sent_argv[0] = "git-upload-archive";
-	for (p = buf;;) {
-		/* This will die if not enough free space in buf */
-		len = packet_read_line(0, p, (buf + sizeof buf) - p);
-		if (len == 0)
+	argv_array_push(&sent_argv, "git-upload-archive");
+	for (;;) {
+		char *buf = packet_read_line(0, NULL);
+		if (!buf)
 			break;	/* got a flush */
-		if (sent_argc > MAX_ARGS - 2)
-			die("Too many options (>%d)", MAX_ARGS - 2);
+		if (sent_argv.argc > MAX_ARGS)
+			die("Too many options (>%d)", MAX_ARGS - 1);
 
-		if (p[len-1] == '\n') {
-			p[--len] = 0;
-		}
-		if (len < strlen(arg_cmd) ||
-		    strncmp(arg_cmd, p, strlen(arg_cmd)))
+		if (prefixcmp(buf, arg_cmd))
 			die("'argument' token or flush expected");
-
-		len -= strlen(arg_cmd);
-		memmove(p, p + strlen(arg_cmd), len);
-		sent_argv[sent_argc++] = p;
-		p += len;
-		*p++ = 0;
+		argv_array_push(&sent_argv, buf + strlen(arg_cmd));
 	}
-	sent_argv[sent_argc] = NULL;
 
 	/* parse all options sent by the client */
-	return write_archive(sent_argc, sent_argv, prefix, 0, NULL, 1);
+	return write_archive(sent_argv.argc, sent_argv.argv, prefix, 0, NULL, 1);
 }
 
 __attribute__((format (printf, 1, 2)))
diff --git a/cache.h b/cache.h
index 59e5b53179..bcdb3edbc4 100644
--- a/cache.h
+++ b/cache.h
@@ -1064,7 +1064,9 @@ struct extra_have_objects {
 	int nr, alloc;
 	unsigned char (*array)[20];
 };
-extern struct ref **get_remote_heads(int in, struct ref **list, unsigned int flags, struct extra_have_objects *);
+extern struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+				     struct ref **list, unsigned int flags,
+				     struct extra_have_objects *);
 extern int server_supports(const char *feature);
 extern int parse_feature_request(const char *features, const char *feature);
 extern const char *server_feature_value(const char *feature, int *len_ret);
diff --git a/connect.c b/connect.c
index 49e56ba35a..f57efd06c1 100644
--- a/connect.c
+++ b/connect.c
@@ -62,8 +62,8 @@ static void die_initial_contact(int got_at_least_one_head)
 /*
  * Read all the refs from the other end
  */
-struct ref **get_remote_heads(int in, struct ref **list,
-			      unsigned int flags,
+struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+			      struct ref **list, unsigned int flags,
 			      struct extra_have_objects *extra_have)
 {
 	int got_at_least_one_head = 0;
@@ -72,18 +72,19 @@ struct ref **get_remote_heads(int in, struct ref **list,
 	for (;;) {
 		struct ref *ref;
 		unsigned char old_sha1[20];
-		static char buffer[1000];
 		char *name;
 		int len, name_len;
+		char *buffer = packet_buffer;
 
-		len = packet_read(in, buffer, sizeof(buffer));
+		len = packet_read(in, &src_buf, &src_len,
+				  packet_buffer, sizeof(packet_buffer),
+				  PACKET_READ_GENTLE_ON_EOF |
+				  PACKET_READ_CHOMP_NEWLINE);
 		if (len < 0)
 			die_initial_contact(got_at_least_one_head);
 
 		if (!len)
 			break;
-		if (buffer[len-1] == '\n')
-			buffer[--len] = 0;
 
 		if (len > 4 && !prefixcmp(buffer, "ERR "))
 			die("remote error: %s", buffer + 4);
diff --git a/daemon.c b/daemon.c
index df8c0ab058..6aeddcb98d 100644
--- a/daemon.c
+++ b/daemon.c
@@ -600,7 +600,7 @@ static void parse_host_arg(char *extra_args, int buflen)
 
 static int execute(void)
 {
-	static char line[1000];
+	char *line = packet_buffer;
 	int pktlen, len, i;
 	char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 
@@ -608,7 +608,7 @@ static int execute(void)
 		loginfo("Connection from %s:%s", addr, port);
 
 	alarm(init_timeout ? init_timeout : timeout);
-	pktlen = packet_read_line(0, line, sizeof(line));
+	pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
 	alarm(0);
 
 	len = strlen(line);
diff --git a/fetch-pack.c b/fetch-pack.c
index cef8fde61b..f156dd4fac 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -172,8 +172,8 @@ static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 		 * shallow and unshallow commands every time there
 		 * is a block of have lines exchanged.
 		 */
-		char line[1000];
-		while (packet_read_line(fd, line, sizeof(line))) {
+		char *line;
+		while ((line = packet_read_line(fd, NULL))) {
 			if (!prefixcmp(line, "shallow "))
 				continue;
 			if (!prefixcmp(line, "unshallow "))
@@ -215,17 +215,17 @@ static int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
 
 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 {
-	static char line[1000];
-	int len = packet_read_line(fd, line, sizeof(line));
+	int len;
+	char *line = packet_read_line(fd, &len);
 
 	if (!len)
 		die("git fetch-pack: expected ACK/NAK, got EOF");
-	if (line[len-1] == '\n')
-		line[--len] = 0;
 	if (!strcmp(line, "NAK"))
 		return NAK;
 	if (!prefixcmp(line, "ACK ")) {
 		if (!get_sha1_hex(line+4, result_sha1)) {
+			if (len < 45)
+				return ACK;
 			if (strstr(line+45, "continue"))
 				return ACK_continue;
 			if (strstr(line+45, "common"))
@@ -245,7 +245,7 @@ static void send_request(struct fetch_pack_args *args,
 		send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 		packet_flush(fd);
 	} else
-		safe_write(fd, buf->buf, buf->len);
+		write_or_die(fd, buf->buf, buf->len);
 }
 
 static void insert_one_alternate_ref(const struct ref *ref, void *unused)
@@ -346,11 +346,11 @@ static int find_common(struct fetch_pack_args *args,
 	state_len = req_buf.len;
 
 	if (args->depth > 0) {
-		char line[1024];
+		char *line;
 		unsigned char sha1[20];
 
 		send_request(args, fd[1], &req_buf);
-		while (packet_read_line(fd[0], line, sizeof(line))) {
+		while ((line = packet_read_line(fd[0], NULL))) {
 			if (!prefixcmp(line, "shallow ")) {
 				if (get_sha1_hex(line + 8, sha1))
 					die("invalid shallow line: %s", line);
diff --git a/http-backend.c b/http-backend.c
index f50e77fb28..8144f3ad5e 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -70,7 +70,7 @@ static void format_write(int fd, const char *fmt, ...)
 	if (n >= sizeof(buffer))
 		die("protocol error: impossibly long line");
 
-	safe_write(fd, buffer, n);
+	write_or_die(fd, buffer, n);
 }
 
 static void http_status(unsigned code, const char *msg)
@@ -111,7 +111,7 @@ static void hdr_cache_forever(void)
 
 static void end_headers(void)
 {
-	safe_write(1, "\r\n", 2);
+	write_or_die(1, "\r\n", 2);
 }
 
 __attribute__((format (printf, 1, 2)))
@@ -157,7 +157,7 @@ static void send_strbuf(const char *type, struct strbuf *buf)
 	hdr_int(content_length, buf->len);
 	hdr_str(content_type, type);
 	end_headers();
-	safe_write(1, buf->buf, buf->len);
+	write_or_die(1, buf->buf, buf->len);
 }
 
 static void send_local_file(const char *the_type, const char *name)
@@ -185,7 +185,7 @@ static void send_local_file(const char *the_type, const char *name)
 			die_errno("Cannot read '%s'", p);
 		if (!n)
 			break;
-		safe_write(1, buf, n);
+		write_or_die(1, buf, n);
 	}
 	close(fd);
 	free(buf);
diff --git a/http.c b/http.c
index d9d1aad3be..8803c70825 100644
--- a/http.c
+++ b/http.c
@@ -5,6 +5,7 @@
 #include "url.h"
 #include "credential.h"
 #include "version.h"
+#include "pkt-line.h"
 
 int active_requests;
 int http_is_verbose;
diff --git a/pkt-line.c b/pkt-line.c
index eaba15f124..70f19501d0 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "pkt-line.h"
 
+char packet_buffer[LARGE_PACKET_MAX];
 static const char *packet_trace_prefix = "git";
 static const char trace_key[] = "GIT_TRACE_PACKET";
 
@@ -47,45 +48,13 @@ static void packet_trace(const char *buf, unsigned int len, int write)
 }
 
 /*
- * Write a packetized stream, where each line is preceded by
- * its length (including the header) as a 4-byte hex number.
- * A length of 'zero' means end of stream (and a length of 1-3
- * would be an error).
- *
- * This is all pretty stupid, but we use this packetized line
- * format to make a streaming format possible without ever
- * over-running the read buffers. That way we'll never read
- * into what might be the pack data (which should go to another
- * process entirely).
- *
- * The writing side could use stdio, but since the reading
- * side can't, we stay with pure read/write interfaces.
- */
-ssize_t safe_write(int fd, const void *buf, ssize_t n)
-{
-	ssize_t nn = n;
-	while (n) {
-		int ret = xwrite(fd, buf, n);
-		if (ret > 0) {
-			buf = (char *) buf + ret;
-			n -= ret;
-			continue;
-		}
-		if (!ret)
-			die("write error (disk full?)");
-		die_errno("write error");
-	}
-	return nn;
-}
-
-/*
  * If we buffered things up above (we don't, but we should),
  * we'd flush it here
  */
 void packet_flush(int fd)
 {
 	packet_trace("0000", 4, 1);
-	safe_write(fd, "0000", 4);
+	write_or_die(fd, "0000", 4);
 }
 
 void packet_buf_flush(struct strbuf *buf)
@@ -121,7 +90,7 @@ void packet_write(int fd, const char *fmt, ...)
 	va_start(args, fmt);
 	n = format_packet(fmt, args);
 	va_end(args);
-	safe_write(fd, buffer, n);
+	write_or_die(fd, buffer, n);
 }
 
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
@@ -135,13 +104,29 @@ void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 	strbuf_add(buf, buffer, n);
 }
 
-static int safe_read(int fd, void *buffer, unsigned size, int return_line_fail)
+static int get_packet_data(int fd, char **src_buf, size_t *src_size,
+			   void *dst, unsigned size, int options)
 {
-	ssize_t ret = read_in_full(fd, buffer, size);
-	if (ret < 0)
-		die_errno("read error");
-	else if (ret < size) {
-		if (return_line_fail)
+	ssize_t ret;
+
+	if (fd >= 0 && src_buf && *src_buf)
+		die("BUG: multiple sources given to packet_read");
+
+	/* Read up to "size" bytes from our source, whatever it is. */
+	if (src_buf && *src_buf) {
+		ret = size < *src_size ? size : *src_size;
+		memcpy(dst, *src_buf, ret);
+		*src_buf += ret;
+		*src_size -= ret;
+	} else {
+		ret = read_in_full(fd, dst, size);
+		if (ret < 0)
+			die_errno("read error");
+	}
+
+	/* And complain if we didn't get enough bytes to satisfy the read. */
+	if (ret < size) {
+		if (options & PACKET_READ_GENTLE_ON_EOF)
 			return -1;
 
 		die("The remote end hung up unexpectedly");
@@ -175,13 +160,14 @@ static int packet_length(const char *linelen)
 	return len;
 }
 
-static int packet_read_internal(int fd, char *buffer, unsigned size, int return_line_fail)
+int packet_read(int fd, char **src_buf, size_t *src_len,
+		char *buffer, unsigned size, int options)
 {
 	int len, ret;
 	char linelen[4];
 
-	ret = safe_read(fd, linelen, 4, return_line_fail);
-	if (return_line_fail && ret < 0)
+	ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
+	if (ret < 0)
 		return ret;
 	len = packet_length(linelen);
 	if (len < 0)
@@ -193,50 +179,37 @@ static int packet_read_internal(int fd, char *buffer, unsigned size, int return_
 	len -= 4;
 	if (len >= size)
 		die("protocol error: bad line length %d", len);
-	ret = safe_read(fd, buffer, len, return_line_fail);
-	if (return_line_fail && ret < 0)
+	ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
+	if (ret < 0)
 		return ret;
+
+	if ((options & PACKET_READ_CHOMP_NEWLINE) &&
+	    len && buffer[len-1] == '\n')
+		len--;
+
 	buffer[len] = 0;
 	packet_trace(buffer, len, 0);
 	return len;
 }
 
-int packet_read(int fd, char *buffer, unsigned size)
+static char *packet_read_line_generic(int fd,
+				      char **src, size_t *src_len,
+				      int *dst_len)
 {
-	return packet_read_internal(fd, buffer, size, 1);
+	int len = packet_read(fd, src, src_len,
+			      packet_buffer, sizeof(packet_buffer),
+			      PACKET_READ_CHOMP_NEWLINE);
+	if (dst_len)
+		*dst_len = len;
+	return len ? packet_buffer : NULL;
 }
 
-int packet_read_line(int fd, char *buffer, unsigned size)
+char *packet_read_line(int fd, int *len_p)
 {
-	return packet_read_internal(fd, buffer, size, 0);
+	return packet_read_line_generic(fd, NULL, NULL, len_p);
 }
 
-int packet_get_line(struct strbuf *out,
-	char **src_buf, size_t *src_len)
+char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
 {
-	int len;
-
-	if (*src_len < 4)
-		return -1;
-	len = packet_length(*src_buf);
-	if (len < 0)
-		return -1;
-	if (!len) {
-		*src_buf += 4;
-		*src_len -= 4;
-		packet_trace("0000", 4, 0);
-		return 0;
-	}
-	if (*src_len < len)
-		return -2;
-
-	*src_buf += 4;
-	*src_len -= 4;
-	len -= 4;
-
-	strbuf_add(out, *src_buf, len);
-	*src_buf += len;
-	*src_len -= len;
-	packet_trace(out->buf, out->len, 0);
-	return len;
+	return packet_read_line_generic(-1, src, src_len, dst_len);
 }
diff --git a/pkt-line.h b/pkt-line.h
index 8cfeb0c31c..0a838d1656 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -5,16 +5,78 @@
 #include "strbuf.h"
 
 /*
- * Silly packetized line writing interface
+ * Write a packetized stream, where each line is preceded by
+ * its length (including the header) as a 4-byte hex number.
+ * A length of 'zero' means end of stream (and a length of 1-3
+ * would be an error).
+ *
+ * This is all pretty stupid, but we use this packetized line
+ * format to make a streaming format possible without ever
+ * over-running the read buffers. That way we'll never read
+ * into what might be the pack data (which should go to another
+ * process entirely).
+ *
+ * The writing side could use stdio, but since the reading
+ * side can't, we stay with pure read/write interfaces.
  */
 void packet_flush(int fd);
 void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 void packet_buf_flush(struct strbuf *buf);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 
-int packet_read_line(int fd, char *buffer, unsigned size);
-int packet_read(int fd, char *buffer, unsigned size);
-int packet_get_line(struct strbuf *out, char **src_buf, size_t *src_len);
-ssize_t safe_write(int, const void *, ssize_t);
+/*
+ * Read a packetized line into the buffer, which must be at least size bytes
+ * long. The return value specifies the number of bytes read into the buffer.
+ *
+ * If src_buffer is not NULL (and nor is *src_buffer), it should point to a
+ * buffer containing the packet data to parse, of at least *src_len bytes.
+ * After the function returns, src_buf will be incremented and src_len
+ * decremented by the number of bytes consumed.
+ *
+ * If src_buffer (or *src_buffer) is NULL, then data is read from the
+ * descriptor "fd".
+ *
+ * If options does not contain PACKET_READ_GENTLE_ON_EOF, we will die under any
+ * of the following conditions:
+ *
+ *   1. Read error from descriptor.
+ *
+ *   2. Protocol error from the remote (e.g., bogus length characters).
+ *
+ *   3. Receiving a packet larger than "size" bytes.
+ *
+ *   4. Truncated output from the remote (e.g., we expected a packet but got
+ *      EOF, or we got a partial packet followed by EOF).
+ *
+ * If options does contain PACKET_READ_GENTLE_ON_EOF, we will not die on
+ * condition 4 (truncated input), but instead return -1. However, we will still
+ * die for the other 3 conditions.
+ *
+ * If options contains PACKET_READ_CHOMP_NEWLINE, a trailing newline (if
+ * present) is removed from the buffer before returning.
+ */
+#define PACKET_READ_GENTLE_ON_EOF (1u<<0)
+#define PACKET_READ_CHOMP_NEWLINE (1u<<1)
+int packet_read(int fd, char **src_buffer, size_t *src_len, char
+		*buffer, unsigned size, int options);
+
+/*
+ * Convenience wrapper for packet_read that is not gentle, and sets the
+ * CHOMP_NEWLINE option. The return value is NULL for a flush packet,
+ * and otherwise points to a static buffer (that may be overwritten by
+ * subsequent calls). If the size parameter is not NULL, the length of the
+ * packet is written to it.
+ */
+char *packet_read_line(int fd, int *size);
+
+/*
+ * Same as packet_read_line, but read from a buf rather than a descriptor;
+ * see packet_read for details on how src_* is used.
+ */
+char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size);
+
+#define DEFAULT_PACKET_MAX 1000
+#define LARGE_PACKET_MAX 65520
+extern char packet_buffer[LARGE_PACKET_MAX];
 
 #endif
diff --git a/remote-curl.c b/remote-curl.c
index 933c69ac26..93a09a64c3 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -76,21 +76,82 @@ struct discovery {
 	char *buf_alloc;
 	char *buf;
 	size_t len;
+	struct ref *refs;
 	unsigned proto_git : 1;
 };
 static struct discovery *last_discovery;
 
+static struct ref *parse_git_refs(struct discovery *heads, int for_push)
+{
+	struct ref *list = NULL;
+	get_remote_heads(-1, heads->buf, heads->len, &list,
+			 for_push ? REF_NORMAL : 0, NULL);
+	return list;
+}
+
+static struct ref *parse_info_refs(struct discovery *heads)
+{
+	char *data, *start, *mid;
+	char *ref_name;
+	int i = 0;
+
+	struct ref *refs = NULL;
+	struct ref *ref = NULL;
+	struct ref *last_ref = NULL;
+
+	data = heads->buf;
+	start = NULL;
+	mid = data;
+	while (i < heads->len) {
+		if (!start) {
+			start = &data[i];
+		}
+		if (data[i] == '\t')
+			mid = &data[i];
+		if (data[i] == '\n') {
+			if (mid - start != 40)
+				die("%sinfo/refs not valid: is this a git repository?", url);
+			data[i] = 0;
+			ref_name = mid + 1;
+			ref = xmalloc(sizeof(struct ref) +
+				      strlen(ref_name) + 1);
+			memset(ref, 0, sizeof(struct ref));
+			strcpy(ref->name, ref_name);
+			get_sha1_hex(start, ref->old_sha1);
+			if (!refs)
+				refs = ref;
+			if (last_ref)
+				last_ref->next = ref;
+			last_ref = ref;
+			start = NULL;
+		}
+		i++;
+	}
+
+	ref = alloc_ref("HEAD");
+	if (!http_fetch_ref(url, ref) &&
+	    !resolve_remote_symref(ref, refs)) {
+		ref->next = refs;
+		refs = ref;
+	} else {
+		free(ref);
+	}
+
+	return refs;
+}
+
 static void free_discovery(struct discovery *d)
 {
 	if (d) {
 		if (d == last_discovery)
 			last_discovery = NULL;
 		free(d->buf_alloc);
+		free_refs(d->refs);
 		free(d);
 	}
 }
 
-static struct discovery* discover_refs(const char *service)
+static struct discovery* discover_refs(const char *service, int for_push)
 {
 	struct strbuf exp = STRBUF_INIT;
 	struct strbuf type = STRBUF_INIT;
@@ -138,32 +199,35 @@ static struct discovery* discover_refs(const char *service)
 	if (maybe_smart &&
 	    (5 <= last->len && last->buf[4] == '#') &&
 	    !strbuf_cmp(&exp, &type)) {
+		char *line;
+
 		/*
 		 * smart HTTP response; validate that the service
 		 * pkt-line matches our request.
 		 */
-		if (packet_get_line(&buffer, &last->buf, &last->len) <= 0)
-			die("%s has invalid packet header", refs_url);
-		if (buffer.len && buffer.buf[buffer.len - 1] == '\n')
-			strbuf_setlen(&buffer, buffer.len - 1);
+		line = packet_read_line_buf(&last->buf, &last->len, NULL);
 
 		strbuf_reset(&exp);
 		strbuf_addf(&exp, "# service=%s", service);
-		if (strbuf_cmp(&exp, &buffer))
-			die("invalid server response; got '%s'", buffer.buf);
+		if (strcmp(line, exp.buf))
+			die("invalid server response; got '%s'", line);
 		strbuf_release(&exp);
 
 		/* The header can include additional metadata lines, up
 		 * until a packet flush marker.  Ignore these now, but
 		 * in the future we might start to scan them.
 		 */
-		strbuf_reset(&buffer);
-		while (packet_get_line(&buffer, &last->buf, &last->len) > 0)
-			strbuf_reset(&buffer);
+		while (packet_read_line_buf(&last->buf, &last->len, NULL))
+			;
 
 		last->proto_git = 1;
 	}
 
+	if (last->proto_git)
+		last->refs = parse_git_refs(last, for_push);
+	else
+		last->refs = parse_info_refs(last);
+
 	free(refs_url);
 	strbuf_release(&exp);
 	strbuf_release(&type);
@@ -172,99 +236,16 @@ static struct discovery* discover_refs(const char *service)
 	return last;
 }
 
-static int write_discovery(int in, int out, void *data)
-{
-	struct discovery *heads = data;
-	int err = 0;
-	if (write_in_full(out, heads->buf, heads->len) != heads->len)
-		err = 1;
-	close(out);
-	return err;
-}
-
-static struct ref *parse_git_refs(struct discovery *heads, int for_push)
-{
-	struct ref *list = NULL;
-	struct async async;
-
-	memset(&async, 0, sizeof(async));
-	async.proc = write_discovery;
-	async.data = heads;
-	async.out = -1;
-
-	if (start_async(&async))
-		die("cannot start thread to parse advertised refs");
-	get_remote_heads(async.out, &list,
-			for_push ? REF_NORMAL : 0, NULL);
-	close(async.out);
-	if (finish_async(&async))
-		die("ref parsing thread failed");
-	return list;
-}
-
-static struct ref *parse_info_refs(struct discovery *heads)
-{
-	char *data, *start, *mid;
-	char *ref_name;
-	int i = 0;
-
-	struct ref *refs = NULL;
-	struct ref *ref = NULL;
-	struct ref *last_ref = NULL;
-
-	data = heads->buf;
-	start = NULL;
-	mid = data;
-	while (i < heads->len) {
-		if (!start) {
-			start = &data[i];
-		}
-		if (data[i] == '\t')
-			mid = &data[i];
-		if (data[i] == '\n') {
-			if (mid - start != 40)
-				die("%sinfo/refs not valid: is this a git repository?", url);
-			data[i] = 0;
-			ref_name = mid + 1;
-			ref = xmalloc(sizeof(struct ref) +
-				      strlen(ref_name) + 1);
-			memset(ref, 0, sizeof(struct ref));
-			strcpy(ref->name, ref_name);
-			get_sha1_hex(start, ref->old_sha1);
-			if (!refs)
-				refs = ref;
-			if (last_ref)
-				last_ref->next = ref;
-			last_ref = ref;
-			start = NULL;
-		}
-		i++;
-	}
-
-	ref = alloc_ref("HEAD");
-	if (!http_fetch_ref(url, ref) &&
-	    !resolve_remote_symref(ref, refs)) {
-		ref->next = refs;
-		refs = ref;
-	} else {
-		free(ref);
-	}
-
-	return refs;
-}
-
 static struct ref *get_refs(int for_push)
 {
 	struct discovery *heads;
 
 	if (for_push)
-		heads = discover_refs("git-receive-pack");
+		heads = discover_refs("git-receive-pack", for_push);
 	else
-		heads = discover_refs("git-upload-pack");
+		heads = discover_refs("git-upload-pack", for_push);
 
-	if (heads->proto_git)
-		return parse_git_refs(heads, for_push);
-	return parse_info_refs(heads);
+	return heads->refs;
 }
 
 static void output_refs(struct ref *refs)
@@ -278,7 +259,6 @@ static void output_refs(struct ref *refs)
 	}
 	printf("\n");
 	fflush(stdout);
-	free_refs(refs);
 }
 
 struct rpc_state {
@@ -308,7 +288,7 @@ static size_t rpc_out(void *ptr, size_t eltsize,
 
 	if (!avail) {
 		rpc->initial_buffer = 0;
-		avail = packet_read_line(rpc->out, rpc->buf, rpc->alloc);
+		avail = packet_read(rpc->out, NULL, NULL, rpc->buf, rpc->alloc, 0);
 		if (!avail)
 			return 0;
 		rpc->pos = 0;
@@ -425,7 +405,7 @@ static int post_rpc(struct rpc_state *rpc)
 			break;
 		}
 
-		n = packet_read_line(rpc->out, buf, left);
+		n = packet_read(rpc->out, NULL, NULL, buf, left, 0);
 		if (!n)
 			break;
 		rpc->len += n;
@@ -579,7 +559,7 @@ static int rpc_service(struct rpc_state *rpc, struct discovery *heads)
 	rpc->hdr_accept = strbuf_detach(&buf, NULL);
 
 	while (!err) {
-		int n = packet_read_line(rpc->out, rpc->buf, rpc->alloc);
+		int n = packet_read(rpc->out, NULL, NULL, rpc->buf, rpc->alloc, 0);
 		if (!n)
 			break;
 		rpc->pos = 0;
@@ -685,7 +665,7 @@ static int fetch_git(struct discovery *heads,
 
 	err = rpc_service(&rpc, heads);
 	if (rpc.result.len)
-		safe_write(1, rpc.result.buf, rpc.result.len);
+		write_or_die(1, rpc.result.buf, rpc.result.len);
 	strbuf_release(&rpc.result);
 	strbuf_release(&preamble);
 	free(depth_arg);
@@ -694,7 +674,7 @@ static int fetch_git(struct discovery *heads,
 
 static int fetch(int nr_heads, struct ref **to_fetch)
 {
-	struct discovery *d = discover_refs("git-upload-pack");
+	struct discovery *d = discover_refs("git-upload-pack", 0);
 	if (d->proto_git)
 		return fetch_git(d, nr_heads, to_fetch);
 	else
@@ -805,7 +785,7 @@ static int push_git(struct discovery *heads, int nr_spec, char **specs)
 
 	err = rpc_service(&rpc, heads);
 	if (rpc.result.len)
-		safe_write(1, rpc.result.buf, rpc.result.len);
+		write_or_die(1, rpc.result.buf, rpc.result.len);
 	strbuf_release(&rpc.result);
 	free(argv);
 	return err;
@@ -813,7 +793,7 @@ static int push_git(struct discovery *heads, int nr_spec, char **specs)
 
 static int push(int nr_spec, char **specs)
 {
-	struct discovery *heads = discover_refs("git-receive-pack");
+	struct discovery *heads = discover_refs("git-receive-pack", 1);
 	int ret;
 
 	if (heads->proto_git)
diff --git a/send-pack.c b/send-pack.c
index 97ab336097..7d172ef37f 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -106,15 +106,11 @@ static int pack_objects(int fd, struct ref *refs, struct extra_have_objects *ext
 static int receive_status(int in, struct ref *refs)
 {
 	struct ref *hint;
-	char line[1000];
 	int ret = 0;
-	int len = packet_read_line(in, line, sizeof(line));
-	if (len < 10 || memcmp(line, "unpack ", 7))
+	char *line = packet_read_line(in, NULL);
+	if (prefixcmp(line, "unpack "))
 		return error("did not receive remote status");
-	if (memcmp(line, "unpack ok\n", 10)) {
-		char *p = line + strlen(line) - 1;
-		if (*p == '\n')
-			*p = '\0';
+	if (strcmp(line, "unpack ok")) {
 		error("unpack failed: %s", line + 7);
 		ret = -1;
 	}
@@ -122,17 +118,15 @@ static int receive_status(int in, struct ref *refs)
 	while (1) {
 		char *refname;
 		char *msg;
-		len = packet_read_line(in, line, sizeof(line));
-		if (!len)
+		line = packet_read_line(in, NULL);
+		if (!line)
 			break;
-		if (len < 3 ||
-		    (memcmp(line, "ok ", 3) && memcmp(line, "ng ", 3))) {
-			fprintf(stderr, "protocol error: %s\n", line);
+		if (prefixcmp(line, "ok ") && prefixcmp(line, "ng ")) {
+			error("invalid ref status from remote: %s", line);
 			ret = -1;
 			break;
 		}
 
-		line[strlen(line)-1] = '\0';
 		refname = line + 3;
 		msg = strchr(refname, ' ');
 		if (msg)
@@ -281,7 +275,7 @@ int send_pack(struct send_pack_args *args,
 			send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
 		}
 	} else {
-		safe_write(out, req_buf.buf, req_buf.len);
+		write_or_die(out, req_buf.buf, req_buf.len);
 		packet_flush(out);
 	}
 	strbuf_release(&req_buf);
diff --git a/sideband.c b/sideband.c
index d5ffa1c891..d1125f5c52 100644
--- a/sideband.c
+++ b/sideband.c
@@ -1,3 +1,4 @@
+#include "cache.h"
 #include "pkt-line.h"
 #include "sideband.h"
 
@@ -37,7 +38,7 @@ int recv_sideband(const char *me, int in_stream, int out)
 
 	while (1) {
 		int band, len;
-		len = packet_read_line(in_stream, buf + pf, LARGE_PACKET_MAX);
+		len = packet_read(in_stream, NULL, NULL, buf + pf, LARGE_PACKET_MAX, 0);
 		if (len == 0)
 			break;
 		if (len < 1) {
@@ -108,7 +109,7 @@ int recv_sideband(const char *me, int in_stream, int out)
 			} while (len);
 			continue;
 		case 1:
-			safe_write(out, buf + pf+1, len);
+			write_or_die(out, buf + pf+1, len);
 			continue;
 		default:
 			fprintf(stderr, "%s: protocol error: bad band #%d\n",
@@ -138,12 +139,12 @@ ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet
 		if (0 <= band) {
 			sprintf(hdr, "%04x", n + 5);
 			hdr[4] = band;
-			safe_write(fd, hdr, 5);
+			write_or_die(fd, hdr, 5);
 		} else {
 			sprintf(hdr, "%04x", n + 4);
-			safe_write(fd, hdr, 4);
+			write_or_die(fd, hdr, 4);
 		}
-		safe_write(fd, p, n);
+		write_or_die(fd, p, n);
 		p += n;
 		sz -= n;
 	}
diff --git a/sideband.h b/sideband.h
index d72db35d1e..e46bed0b01 100644
--- a/sideband.h
+++ b/sideband.h
@@ -4,9 +4,6 @@
 #define SIDEBAND_PROTOCOL_ERROR -2
 #define SIDEBAND_REMOTE_ERROR -1
 
-#define DEFAULT_PACKET_MAX 1000
-#define LARGE_PACKET_MAX 65520
-
 int recv_sideband(const char *me, int in_stream, int out);
 ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max);
 
diff --git a/t/t5503-tagfollow.sh b/t/t5503-tagfollow.sh
index 60de2d6ede..f30c03885c 100755
--- a/t/t5503-tagfollow.sh
+++ b/t/t5503-tagfollow.sh
@@ -4,10 +4,6 @@ test_description='test automatic tag following'
 
 . ./test-lib.sh
 
-if ! test_have_prereq NOT_MINGW; then
-	say "GIT_DEBUG_SEND_PACK not supported - skipping tests"
-fi
-
 # End state of the repository:
 #
 #         T - tag1          S - tag2
@@ -17,7 +13,7 @@ fi
 #     \   C - origin/cat    \
 #      origin/master         master
 
-test_expect_success NOT_MINGW setup '
+test_expect_success setup '
 	test_tick &&
 	echo ichi >file &&
 	git add file &&
@@ -39,28 +35,35 @@ test_expect_success NOT_MINGW setup '
 '
 
 U=UPLOAD_LOG
+UPATH="$(pwd)/$U"
 
-test_expect_success NOT_MINGW 'setup expect' '
+test_expect_success 'setup expect' '
 cat - <<EOF >expect
-#S
 want $A
-#E
 EOF
 '
 
-test_expect_success NOT_MINGW 'fetch A (new commit : 1 connection)' '
+get_needs () {
+	test -s "$1" &&
+	perl -alne '
+		next unless $F[1] eq "upload-pack<";
+		last if $F[2] eq "0000";
+		print $F[2], " ", $F[3];
+	' "$1"
+}
+
+test_expect_success 'fetch A (new commit : 1 connection)' '
 	rm -f $U &&
 	(
 		cd cloned &&
-		GIT_DEBUG_SEND_PACK=3 git fetch 3>../$U &&
+		GIT_TRACE_PACKET=$UPATH git fetch &&
 		test $A = $(git rev-parse --verify origin/master)
 	) &&
-	test -s $U &&
-	cut -d" " -f1,2 $U >actual &&
+	get_needs $U >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success NOT_MINGW "create tag T on A, create C on branch cat" '
+test_expect_success "create tag T on A, create C on branch cat" '
 	git tag -a -m tag1 tag1 $A &&
 	T=$(git rev-parse --verify tag1) &&
 
@@ -72,30 +75,27 @@ test_expect_success NOT_MINGW "create tag T on A, create C on branch cat" '
 	git checkout master
 '
 
-test_expect_success NOT_MINGW 'setup expect' '
+test_expect_success 'setup expect' '
 cat - <<EOF >expect
-#S
 want $C
 want $T
-#E
 EOF
 '
 
-test_expect_success NOT_MINGW 'fetch C, T (new branch, tag : 1 connection)' '
+test_expect_success 'fetch C, T (new branch, tag : 1 connection)' '
 	rm -f $U &&
 	(
 		cd cloned &&
-		GIT_DEBUG_SEND_PACK=3 git fetch 3>../$U &&
+		GIT_TRACE_PACKET=$UPATH git fetch &&
 		test $C = $(git rev-parse --verify origin/cat) &&
 		test $T = $(git rev-parse --verify tag1) &&
 		test $A = $(git rev-parse --verify tag1^0)
 	) &&
-	test -s $U &&
-	cut -d" " -f1,2 $U >actual &&
+	get_needs $U >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success NOT_MINGW "create commits O, B, tag S on B" '
+test_expect_success "create commits O, B, tag S on B" '
 	test_tick &&
 	echo O >file &&
 	git add file &&
@@ -111,39 +111,34 @@ test_expect_success NOT_MINGW "create commits O, B, tag S on B" '
 	S=$(git rev-parse --verify tag2)
 '
 
-test_expect_success NOT_MINGW 'setup expect' '
+test_expect_success 'setup expect' '
 cat - <<EOF >expect
-#S
 want $B
 want $S
-#E
 EOF
 '
 
-test_expect_success NOT_MINGW 'fetch B, S (commit and tag : 1 connection)' '
+test_expect_success 'fetch B, S (commit and tag : 1 connection)' '
 	rm -f $U &&
 	(
 		cd cloned &&
-		GIT_DEBUG_SEND_PACK=3 git fetch 3>../$U &&
+		GIT_TRACE_PACKET=$UPATH git fetch &&
 		test $B = $(git rev-parse --verify origin/master) &&
 		test $B = $(git rev-parse --verify tag2^0) &&
 		test $S = $(git rev-parse --verify tag2)
 	) &&
-	test -s $U &&
-	cut -d" " -f1,2 $U >actual &&
+	get_needs $U >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success NOT_MINGW 'setup expect' '
+test_expect_success 'setup expect' '
 cat - <<EOF >expect
-#S
 want $B
 want $S
-#E
 EOF
 '
 
-test_expect_success NOT_MINGW 'new clone fetch master and tags' '
+test_expect_success 'new clone fetch master and tags' '
 	git branch -D cat
 	rm -f $U
 	(
@@ -151,15 +146,14 @@ test_expect_success NOT_MINGW 'new clone fetch master and tags' '
 		cd clone2 &&
 		git init &&
 		git remote add origin .. &&
-		GIT_DEBUG_SEND_PACK=3 git fetch 3>../$U &&
+		GIT_TRACE_PACKET=$UPATH git fetch &&
 		test $B = $(git rev-parse --verify origin/master) &&
 		test $S = $(git rev-parse --verify tag2) &&
 		test $B = $(git rev-parse --verify tag2^0) &&
 		test $T = $(git rev-parse --verify tag1) &&
 		test $A = $(git rev-parse --verify tag1^0)
 	) &&
-	test -s $U &&
-	cut -d" " -f1,2 $U >actual &&
+	get_needs $U >actual &&
 	test_cmp expect actual
 '
 
diff --git a/t/t5700-clone-reference.sh b/t/t5700-clone-reference.sh
index c47d450cc3..60f1552ade 100755
--- a/t/t5700-clone-reference.sh
+++ b/t/t5700-clone-reference.sh
@@ -54,11 +54,14 @@ cd "$base_dir"
 
 rm -f "$U.D"
 
-test_expect_success 'cloning with reference (no -l -s)' \
-'GIT_DEBUG_SEND_PACK=3 git clone --reference B "file://$(pwd)/A" D 3>"$U.D"'
+test_expect_success 'cloning with reference (no -l -s)' '
+	GIT_TRACE_PACKET=$U.D git clone --reference B "file://$(pwd)/A" D
+'
 
-test_expect_success 'fetched no objects' \
-'! grep "^want" "$U.D"'
+test_expect_success 'fetched no objects' '
+	test -s "$U.D" &&
+	! grep " want" "$U.D"
+'
 
 cd "$base_dir"
 
@@ -173,12 +176,13 @@ test_expect_success 'fetch with incomplete alternates' '
 	(
 		cd K &&
 		git remote add J "file://$base_dir/J" &&
-		GIT_DEBUG_SEND_PACK=3 git fetch J 3>"$U.K"
+		GIT_TRACE_PACKET=$U.K git fetch J
 	) &&
 	master_object=$(cd A && git for-each-ref --format="%(objectname)" refs/heads/master) &&
-	! grep "^want $master_object" "$U.K" &&
+	test -s "$U.K" &&
+	! grep " want $master_object" "$U.K" &&
 	tag_object=$(cd A && git for-each-ref --format="%(objectname)" refs/tags/HEAD) &&
-	! grep "^want $tag_object" "$U.K"
+	! grep " want $tag_object" "$U.K"
 '
 
 test_done
diff --git a/transport.c b/transport.c
index eb9eb33e0f..ba5d8afb1b 100644
--- a/transport.c
+++ b/transport.c
@@ -508,7 +508,7 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 	struct ref *refs;
 
 	connect_setup(transport, for_push, 0);
-	get_remote_heads(data->fd[0], &refs,
+	get_remote_heads(data->fd[0], NULL, 0, &refs,
 			 for_push ? REF_NORMAL : 0, &data->extra_have);
 	data->got_remote_heads = 1;
 
@@ -537,7 +537,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 
 	if (!data->got_remote_heads) {
 		connect_setup(transport, 0, 0);
-		get_remote_heads(data->fd[0], &refs_tmp, 0, NULL);
+		get_remote_heads(data->fd[0], NULL, 0, &refs_tmp, 0, NULL);
 		data->got_remote_heads = 1;
 	}
 
@@ -795,7 +795,7 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 		struct ref *tmp_refs;
 		connect_setup(transport, 1, 0);
 
-		get_remote_heads(data->fd[0], &tmp_refs, REF_NORMAL, NULL);
+		get_remote_heads(data->fd[0], NULL, 0, &tmp_refs, REF_NORMAL, NULL);
 		data->got_remote_heads = 1;
 	}
 
diff --git a/upload-pack.c b/upload-pack.c
index f5673ee4c2..bfa6279cc4 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -44,7 +44,6 @@ static unsigned int timeout;
  * otherwise maximum packet size (up to 65520 bytes).
  */
 static int use_sideband;
-static int debug_fd;
 static int advertise_refs;
 static int stateless_rpc;
 
@@ -53,13 +52,6 @@ static void reset_timeout(void)
 	alarm(timeout);
 }
 
-static int strip(char *line, int len)
-{
-	if (len && line[len-1] == '\n')
-		line[--len] = 0;
-	return len;
-}
-
 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
 {
 	if (use_sideband)
@@ -72,7 +64,8 @@ static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
 		xwrite(fd, data, sz);
 		return sz;
 	}
-	return safe_write(fd, data, sz);
+	write_or_die(fd, data, sz);
+	return sz;
 }
 
 static FILE *pack_pipe = NULL;
@@ -415,7 +408,6 @@ static int ok_to_give_up(void)
 
 static int get_common_commits(void)
 {
-	static char line[1000];
 	unsigned char sha1[20];
 	char last_hex[41];
 	int got_common = 0;
@@ -425,10 +417,10 @@ static int get_common_commits(void)
 	save_commit_buffer = 0;
 
 	for (;;) {
-		int len = packet_read_line(0, line, sizeof(line));
+		char *line = packet_read_line(0, NULL);
 		reset_timeout();
 
-		if (!len) {
+		if (!line) {
 			if (multi_ack == 2 && got_common
 			    && !got_other && ok_to_give_up()) {
 				sent_ready = 1;
@@ -447,7 +439,6 @@ static int get_common_commits(void)
 			got_other = 0;
 			continue;
 		}
-		strip(line, len);
 		if (!prefixcmp(line, "have ")) {
 			switch (got_sha1(line+5, sha1)) {
 			case -1: /* they have what we do not */
@@ -581,36 +572,33 @@ error:
 static void receive_needs(void)
 {
 	struct object_array shallows = OBJECT_ARRAY_INIT;
-	static char line[1000];
-	int len, depth = 0;
+	int depth = 0;
 	int has_non_tip = 0;
 
 	shallow_nr = 0;
-	if (debug_fd)
-		write_str_in_full(debug_fd, "#S\n");
 	for (;;) {
 		struct object *o;
 		const char *features;
 		unsigned char sha1_buf[20];
-		len = packet_read_line(0, line, sizeof(line));
+		char *line = packet_read_line(0, NULL);
 		reset_timeout();
-		if (!len)
+		if (!line)
 			break;
-		if (debug_fd)
-			write_in_full(debug_fd, line, len);
 
 		if (!prefixcmp(line, "shallow ")) {
 			unsigned char sha1[20];
 			struct object *object;
-			if (get_sha1(line + 8, sha1))
+			if (get_sha1_hex(line + 8, sha1))
 				die("invalid shallow line: %s", line);
 			object = parse_object(sha1);
 			if (!object)
 				die("did not find object for %s", line);
 			if (object->type != OBJ_COMMIT)
 				die("invalid shallow object %s", sha1_to_hex(sha1));
-			object->flags |= CLIENT_SHALLOW;
-			add_object_array(object, NULL, &shallows);
+			if (!(object->flags & CLIENT_SHALLOW)) {
+				object->flags |= CLIENT_SHALLOW;
+				add_object_array(object, NULL, &shallows);
+			}
 			continue;
 		}
 		if (!prefixcmp(line, "deepen ")) {
@@ -657,8 +645,6 @@ static void receive_needs(void)
 			add_object_array(o, NULL, &want_obj);
 		}
 	}
-	if (debug_fd)
-		write_str_in_full(debug_fd, "#E\n");
 
 	/*
 	 * We have sent all our refs already, and the other end
@@ -854,8 +840,6 @@ int main(int argc, char **argv)
 	if (is_repository_shallow())
 		die("attempt to fetch/clone from a shallow repository");
 	git_config(upload_pack_config, NULL);
-	if (getenv("GIT_DEBUG_SEND_PACK"))
-		debug_fd = atoi(getenv("GIT_DEBUG_SEND_PACK"));
 	upload_pack();
 	return 0;
 }
diff --git a/write_or_die.c b/write_or_die.c
index 960f448cff..b50f99a936 100644
--- a/write_or_die.c
+++ b/write_or_die.c
@@ -1,5 +1,15 @@
 #include "cache.h"
 
+static void check_pipe(int err)
+{
+	if (err == EPIPE) {
+		signal(SIGPIPE, SIG_DFL);
+		raise(SIGPIPE);
+		/* Should never happen, but just in case... */
+		exit(141);
+	}
+}
+
 /*
  * Some cases use stdio, but want to flush after the write
  * to get error handling (and to get better interactive
@@ -34,8 +44,7 @@ void maybe_flush_or_die(FILE *f, const char *desc)
 			return;
 	}
 	if (fflush(f)) {
-		if (errno == EPIPE)
-			exit(0);
+		check_pipe(errno);
 		die_errno("write failure on '%s'", desc);
 	}
 }
@@ -50,8 +59,7 @@ void fsync_or_die(int fd, const char *msg)
 void write_or_die(int fd, const void *buf, size_t count)
 {
 	if (write_in_full(fd, buf, count) < 0) {
-		if (errno == EPIPE)
-			exit(0);
+		check_pipe(errno);
 		die_errno("write error");
 	}
 }
@@ -59,8 +67,7 @@ void write_or_die(int fd, const void *buf, size_t count)
 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
 {
 	if (write_in_full(fd, buf, count) < 0) {
-		if (errno == EPIPE)
-			exit(0);
+		check_pipe(errno);
 		fprintf(stderr, "%s: write error (%s)\n",
 			msg, strerror(errno));
 		return 0;