In read_batch mode, we read ints from the new batch_gen_fd pipe and

only process the updates from the batch file when the generator has
indicated that it is ready (which ensures that all the necessary
dirs have been created).

receiver.c

@@ -28,6 +28,8 @@ extern int max_delete;
 extern int csum_length;
 extern struct stats stats;
 extern int dry_run;
+extern int read_batch;
+extern int batch_gen_fd;
 extern int am_server;
 extern int relative_paths;
 extern int keep_dirlinks;
@@ -330,6 +332,7 @@ static void discard_receive_data(int f_in, OFF_T length)
  * Receiver process runs on the same host as the generator process. */
 int recv_files(int f_in, struct file_list *flist, char *local_name)
 {
+	int next_gen_i = -1;
 	int fd1,fd2;
 	STRUCT_STAT st;
 	char *fname, fbuf[MAXPATHLEN];
@@ -355,6 +358,12 @@ int recv_files(int f_in, struct file_list *flist, char *local_name)
 
 		i = read_int(f_in);
 		if (i == -1) {
+			if (read_batch) {
+				if (next_gen_i != flist->count)
+					while (read_int(batch_gen_fd) != -1) {}
+				next_gen_i = -1;
+			}
+
 			if (phase)
 				break;
 
@@ -399,6 +408,20 @@ int recv_files(int f_in, struct file_list *flist, char *local_name)
 
 		fnamecmp = fname;
 
+		if (read_batch) {
+			while (i > next_gen_i) {
+				next_gen_i = read_int(batch_gen_fd);
+				if (next_gen_i == -1)
+					next_gen_i = flist->count;
+			}
+			if (i < next_gen_i) {
+				rprintf(FINFO, "skipping update for \"%s\"\n",
+					fname);
+				discard_receive_data(f_in, file->length);
+				continue;
+			}
+		}
+
 		if (server_exclude_list.head
 		    && check_exclude(&server_exclude_list, fname,
 				     S_ISDIR(file->mode)) < 0) {