Fixed some backward-compatibility issues with --files-from.

flist.c

@@ -52,6 +52,7 @@ extern int preserve_hard_links;
 extern int preserve_devices;
 extern int preserve_specials;
 extern int missing_args;
+extern int sock_f_in;
 extern int uid_ndx;
 extern int gid_ndx;
 extern int eol_nulls;
@@ -2092,6 +2093,13 @@ struct file_list *send_file_list(int f, int argc, char *argv[])
 				full_fname(argv[0]));
 			exit_cleanup(RERR_FILESELECT);
 		}
+		if (protocol_version == 30) {
+			/* Older protocols send the files-from data w/o packaging it in
+			 * multiplexed I/O packets, but protocol 30 messed up and did
+			 * this after starting multiplexing.  We'll temporarily switch
+			 * to buffered I/O to match this behavior. */
+			io_end_multiplex_in(MPLX_TO_BUFFERED);
+		}
 		use_ff_fd = 1;
 	}
 
@@ -2297,6 +2305,9 @@ struct file_list *send_file_list(int f, int argc, char *argv[])
 			send_file_name(f, flist, fbuf, &st, flags, NO_FILTERS);
 	}
 
+	if (use_ff_fd && protocol_version == 30)
+		io_start_multiplex_in(sock_f_in);
+
 	gettimeofday(&end_tv, NULL);
 	stats.flist_buildtime = (int64)(end_tv.tv_sec - start_tv.tv_sec) * 1000
 			      + (end_tv.tv_usec - start_tv.tv_usec) / 1000;
@@ -2352,7 +2363,7 @@ struct file_list *send_file_list(int f, int argc, char *argv[])
 		send_msg_int(MSG_IO_ERROR, io_error);
 
 	if (disable_buffering)
-		io_end_buffering_out(True);
+		io_end_buffering_out(IOBUF_FREE_BUFS);
 
 	stats.flist_size = stats.total_written - start_write;
 	stats.num_files = flist->used;

io.c

@@ -348,7 +348,7 @@ static void forward_filesfrom_data(void)
 			ff_forward_fd = -1;
 			write_buf(iobuf.out_fd, "\0\0", ff_lastchar ? 2 : 1);
 			free_xbuf(&ff_xb);
-			if (protocol_version < 31)
+			if (protocol_version == 30)
 				io_start_multiplex_out(iobuf.out_fd);
 		}
 		return;
@@ -1016,18 +1016,15 @@ int get_hlink_num(void)
  * for recv_file_list() to use. */
 void start_filesfrom_forwarding(int fd)
 {
-	ff_forward_fd = fd;
-	if (protocol_version < 31) {
-		int save_fd = iobuf.out_fd;
+	if (protocol_version == 30) {
 		/* Older protocols send the files-from data w/o packaging it in
-		 * multiplexed I/O packets.  To match this, we temporarily turn
-		 * off the multiplexing of our output w/o disabling buffering. */
-		assert(OUT_MULTIPLEXED);
-		/* Be extra, extra sure no messages go out before files-from data. */
-		iobuf.msg.pos = iobuf.msg.len = 0;
-		io_end_multiplex_out(False);
-		iobuf.out_fd = save_fd;
+		 * multiplexed I/O packets, but protocol 30 messed up and did
+		 * this after starting multiplexing.  We'll temporarily switch
+		 * to buffered I/O to match this behavior. */
+		iobuf.msg.pos = iobuf.msg.len = 0; /* Be extra sure no messages go out. */
+		io_end_multiplex_out(MPLX_TO_BUFFERED);
 	}
+	ff_forward_fd = fd;
 
 	alloc_xbuf(&ff_xb, FILESFROM_BUFLEN);
 }
@@ -1192,9 +1189,9 @@ int io_start_buffering_in(int f_in)
 
 void io_end_buffering_in(BOOL free_buffers)
 {
-	if (DEBUG_GTE(IO, 2)) {
-		rprintf(FINFO, "[%s] io_end_buffering_in(%s)\n",
-			who_am_i(), free_buffers ? "True" : "False");
+	if (msgs2stderr && DEBUG_GTE(IO, 2)) {
+		rprintf(FINFO, "[%s] io_end_buffering_in(IOBUF_%s_BUFS)\n",
+			who_am_i(), free_buffers ? "FREE" : "KEEP");
 	}
 
 	if (free_buffers)
@@ -1207,9 +1204,9 @@ void io_end_buffering_in(BOOL free_buffers)
 
 void io_end_buffering_out(BOOL free_buffers)
 {
-	if (DEBUG_GTE(IO, 2)) {
-		rprintf(FINFO, "[%s] io_end_buffering_out(%s)\n",
-			who_am_i(), free_buffers ? "True" : "False");
+	if (msgs2stderr && DEBUG_GTE(IO, 2)) {
+		rprintf(FINFO, "[%s] io_end_buffering_out(IOBUF_%s_BUFS)\n",
+			who_am_i(), free_buffers ? "FREE" : "KEEP");
 	}
 
 	io_flush(FULL_FLUSH);
@@ -1217,9 +1214,6 @@ void io_end_buffering_out(BOOL free_buffers)
 	if (free_buffers) {
 		free_xbuf(&iobuf.out);
 		free_xbuf(&iobuf.msg);
-	} else {
-		iobuf.out.pos = iobuf.out.len = 0;
-		iobuf.msg.pos = iobuf.msg.len = 0;
 	}
 
 	iobuf.out_fd = -1;
@@ -2045,11 +2039,11 @@ void io_printf(int fd, const char *format, ...)
 /* Setup for multiplexing a MSG_* stream with the data stream. */
 void io_start_multiplex_out(int fd)
 {
+	io_flush(FULL_FLUSH);
+
 	if (msgs2stderr && DEBUG_GTE(IO, 2))
 		rprintf(FINFO, "[%s] io_start_multiplex_out(%d)\n", who_am_i(), fd);
 
-	io_flush(FULL_FLUSH);
-
 	iobuf.out_empty_len = 4; /* See also OUT_MULTIPLEXED */
 	io_start_buffering_out(fd);
 
@@ -2067,27 +2061,32 @@ void io_start_multiplex_in(int fd)
 	io_start_buffering_in(fd);
 }
 
-void io_end_multiplex_in(BOOL free_buffers)
+void io_end_multiplex_in(int mode)
 {
-	if (DEBUG_GTE(IO, 2)) {
-		rprintf(FINFO, "[%s] io_end_multiplex_in(%s)\n",
-			who_am_i(), free_buffers ? "True" : "False");
-	}
+	if (msgs2stderr && DEBUG_GTE(IO, 2))
+		rprintf(FINFO, "[%s] io_end_multiplex_in(mode=%d)\n", who_am_i(), mode);
 
 	iobuf.in_multiplexed = False;
-	iobuf.raw_input_ends_before = 0;
-	io_end_buffering_in(free_buffers);
+	if (mode == MPLX_SWITCHING)
+		iobuf.raw_input_ends_before = 0;
+	else
+		assert(iobuf.raw_input_ends_before == 0);
+	if (mode != MPLX_TO_BUFFERED)
+		io_end_buffering_in(mode);
 }
 
 /* Stop output multiplexing. */
-void io_end_multiplex_out(BOOL free_buffers)
+void io_end_multiplex_out(int mode)
 {
-	if (DEBUG_GTE(IO, 2)) {
-		rprintf(FINFO, "[%s] io_end_multiplex_out(%s)\n",
-			who_am_i(), free_buffers ? "True" : "False");
-	}
+	if (msgs2stderr && DEBUG_GTE(IO, 2))
+		rprintf(FINFO, "[%s] io_end_multiplex_out(mode=%d)\n", who_am_i(), mode);
 
-	io_end_buffering_out(free_buffers);
+	if (mode != MPLX_TO_BUFFERED)
+		io_end_buffering_out(mode);
+	else
+		io_flush(FULL_FLUSH);
+
+	iobuf.out.len = 0;
 	iobuf.out_empty_len = 0;
 }
 

main.c

@@ -848,7 +848,7 @@ static int do_recv(int f_in, int f_out, char *local_name)
 		close(error_pipe[0]);
 
 		/* We can't let two processes write to the socket at one time. */
-		io_end_multiplex_out(False);
+		io_end_multiplex_out(MPLX_SWITCHING);
 		if (f_in != f_out)
 			close(f_out);
 		sock_f_out = -1;
@@ -895,7 +895,7 @@ static int do_recv(int f_in, int f_out, char *local_name)
 
 	am_generator = 1;
 
-	io_end_multiplex_in(False);
+	io_end_multiplex_in(MPLX_SWITCHING);
 	if (write_batch && !am_server)
 		stop_write_batch();
 
@@ -1056,6 +1056,8 @@ void start_server(int f_in, int f_out, int argc, char *argv[])
 		keep_dirlinks = 0; /* Must be disabled on the sender. */
 		if (need_messages_from_generator)
 			io_start_multiplex_in(f_in);
+		else
+			io_start_buffering_in(f_in);
 		recv_filter_list(f_in);
 		do_server_sender(f_in, f_out, argc, argv);
 	} else
@@ -1104,6 +1106,8 @@ int client_run(int f_in, int f_out, pid_t pid, int argc, char *argv[])
 			io_start_buffering_out(f_out);
 		if (protocol_version >= 31 || (!filesfrom_host && protocol_version >= 23))
 			io_start_multiplex_in(f_in);
+		else
+			io_start_buffering_in(f_in);
 		send_filter_list(f_out);
 		if (filesfrom_host)
 			filesfrom_fd = f_in;
@@ -1139,6 +1143,8 @@ int client_run(int f_in, int f_out, pid_t pid, int argc, char *argv[])
 			io_start_multiplex_in(f_in);
 		if (need_messages_from_generator)
 			io_start_multiplex_out(f_out);
+		else
+			io_start_buffering_out(f_out);
 	}
 
 	send_filter_list(read_batch ? -1 : f_out);

rsync.h

@@ -903,6 +903,13 @@ typedef struct {
 #define ICB_CIRCULAR_OUT (1<<3)
 #define ICB_INIT (1<<4)
 
+#define IOBUF_KEEP_BUFS 0
+#define IOBUF_FREE_BUFS 1
+
+#define MPLX_SWITCHING IOBUF_KEEP_BUFS
+#define MPLX_ALL_DONE IOBUF_FREE_BUFS
+#define MPLX_TO_BUFFERED 2
+
 #define RL_EOL_NULLS (1<<0)
 #define RL_DUMP_COMMENTS (1<<1)
 #define RL_CONVERT (1<<2)