--- orig/batch.c	2004-05-15 20:10:13
+++ batch.c	2004-07-03 20:20:27
@@ -172,6 +172,7 @@ void close_batch_csums_file(void)
 
 /**
  * Write csum info to batch file
+ * If flist_entry < 0, just open the file
  *
  * @todo This will break if s->count is ever larger than maxint.  The
  * batch code should probably be changed to consistently use the
@@ -198,6 +199,9 @@ void write_batch_csum_info(int *flist_en
 		}
 	}
 
+	if (*flist_entry < 0)
+		return;
+
 	write_batch_csums_file(flist_entry, sizeof (int));
 	int_count = s ? (int) s->count : 0;
 	write_batch_csums_file(&int_count, sizeof int_count);
@@ -285,6 +289,9 @@ void write_batch_delta_file(char *buff, 
 		}
 	}
 
+	if (!buff)
+		return;
+
 	if (write(f_delta, buff, bytes_to_write) < 0) {
 		rsyserr(FERROR, errno, "Batch file %s write error", filename);
 		close(f_delta);
--- orig/flist.c	2004-06-18 16:23:07
+++ flist.c	2004-07-03 20:20:27
@@ -950,7 +950,7 @@ void send_file_name(int f, struct file_l
 
 	flist_expand(flist);
 
-	if (write_batch)
+	if (write_batch)  /* TODO: why? remove and test. */
 		file->flags |= FLAG_TOP_DIR;
 
 	if (file->basename[0]) {
@@ -1308,6 +1308,18 @@ struct file_list *recv_file_list(int f)
 			else
 				io_error |= read_int(f);
 		}
+		if (write_batch) {
+			/* TODO: remove this FLAG_TOP_DIR stuff and test
+			 * CAS: I'm not sure what the FLAG_TOP_DIR does,
+			 * but we set it here, just so it matches what
+			 * happens for write_batch on the sender paths.
+			 */
+		    int i;
+		    for (i = 0; i < flist->count; i++)
+			    flist->files[i]->flags |= FLAG_TOP_DIR;
+
+		    write_batch_flist_info(flist->count, flist->files);
+		}
 	}
 
 	if (verbose > 3)
--- orig/generator.c	2004-06-30 07:24:45
+++ generator.c	2004-07-03 20:20:27
@@ -48,6 +48,7 @@ extern int whole_file;
 extern int local_server;
 extern int read_batch;
 extern int write_batch;
+extern int read_batch;
 extern int list_only;
 extern int only_existing;
 extern int orig_umask;
@@ -224,16 +225,27 @@ static BOOL disable_deltas_p(void)
  * Generate and send a stream of signatures/checksums that describe a buffer
  *
  * Generate approximately one checksum every block_len bytes.
+ *
+ * The flist_idx arg is only for the purpose of being able to call
+ * write_batch_csum_info().  Another (better?) way would be to instead
+ * return a pointer to a sum_struct, and then call write_batch_csum_info()
+ * outside.
  */
-static void generate_and_send_sums(struct map_struct *buf, size_t len, int f_out)
+static void generate_and_send_sums(struct map_struct *buf, size_t len, int f_out,
+				   int flist_idx)
 {
-	size_t i;
+	size_t i, j;
 	struct sum_struct sum;
 	OFF_T offset = 0;
 
 	sum_sizes_sqroot(&sum, len);
 
 	write_sum_head(f_out, &sum);
+	if (write_batch) { /* save all the sums to write out */
+		sum.sums = new_array(struct sum_buf, sum.count);
+		if (!sum.sums)
+			out_of_memory("generate_and_send_sums");
+	}
 
 	for (i = 0; i < sum.count; i++) {
 		unsigned int n1 = MIN(len, sum.blength);
@@ -253,10 +265,30 @@ static void generate_and_send_sums(struc
 		write_buf(f_out, sum2, sum.s2length);
 		len -= n1;
 		offset += n1;
+		
+		if (write_batch) {  /* we're receiver */
+			/* we only have to save the sums
+			 * if we want to write them out */
+			sum.sums[i].sum1 = sum1;
+			for (j = 0; j < SUM_LENGTH ; j++)
+				sum.sums[i].sum2[j] = sum2[j];
+		}
+	}
+	if (write_batch) {
+		write_batch_csum_info(&flist_idx, &sum);
+		free(sum.sums);
 	}
 }
 
 
+void write_null_sum(int f_out, int i)
+{
+	write_int(f_out, i);
+	if (!dry_run)
+		write_sum_head(f_out, NULL);
+	if (write_batch)
+		write_batch_csum_info(&i, NULL);
+}
 
 /*
  * Acts on file number @p i from @p flist, whose name is @p fname.
@@ -452,9 +484,7 @@ static void recv_generator(char *fname, 
 		if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 			return;
 		if (errno == ENOENT) {
-			write_int(f_out,i);
-			if (!dry_run)
-				write_sum_head(f_out, NULL);
+			write_null_sum(f_out, i);
 		} else if (verbose > 1) {
 			rsyserr(FERROR, errno,
 				"recv_generator: failed to open %s",
@@ -471,9 +501,7 @@ static void recv_generator(char *fname, 
 		/* now pretend the file didn't exist */
 		if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 			return;
-		write_int(f_out,i);
-		if (!dry_run)
-			write_sum_head(f_out, NULL);
+		write_null_sum(f_out, i);
 		return;
 	}
 
@@ -502,8 +530,7 @@ static void recv_generator(char *fname, 
 	}
 
 	if (disable_deltas_p()) {
-		write_int(f_out,i);
-		write_sum_head(f_out, NULL);
+		write_null_sum(f_out, i);
 		return;
 	}
 
@@ -516,8 +543,7 @@ static void recv_generator(char *fname, 
 		/* pretend the file didn't exist */
 		if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 			return;
-		write_int(f_out,i);
-		write_sum_head(f_out, NULL);
+		write_null_sum(f_out, i);
 		return;
 	}
 
@@ -535,7 +561,7 @@ static void recv_generator(char *fname, 
 		rprintf(FINFO, "generating and sending sums for %d\n", i);
 
 	write_int(f_out,i);
-	generate_and_send_sums(mapbuf, st.st_size, f_out);
+	generate_and_send_sums(mapbuf, st.st_size, f_out, i);
 
 	close(fd);
 	if (mapbuf)
--- orig/main.c	2004-06-30 07:24:30
+++ main.c	2004-07-03 20:20:27
@@ -1039,6 +1039,10 @@ int main(int argc,char *argv[])
 
 	if (write_batch && !am_server) {
 		write_batch_argvs_file(orig_argc, orig_argv);
+		/* initialize static fds */
+		ret = -1;
+		write_batch_csum_info(&ret, NULL);
+		write_batch_delta_file(NULL, 0);
 	}
 
 	if (am_daemon && !am_server)
--- orig/options.c	2004-06-20 19:30:00
+++ options.c	2004-07-03 20:20:27
@@ -643,6 +643,15 @@ int parse_arguments(int *argc, const cha
 			"write-batch and read-batch can not be used together\n");
 		exit_cleanup(RERR_SYNTAX);
 	}
+	if ((write_batch || read_batch) && am_server) {
+		rprintf(FERROR,
+			"batch-mode is incompatible with server mode\n");
+		write_batch = 0;
+		read_batch = 0;
+		/* We don't actually exit_cleanup(), so that we can still
+		 * service older version clients that send batch args to
+		 * the server. */
+	}
 	if (batch_prefix && strlen(batch_prefix) > MAX_BATCH_PREFIX_LEN) {
 		rprintf(FERROR,
 			"the batch-file prefix must be %d characters or less.\n",
@@ -884,13 +893,6 @@ void server_options(char **args,int *arg
 		args[ac++] = arg;
 	}
 
-	if (batch_prefix) {
-		char *r_or_w = write_batch ? "write" : "read";
-		if (asprintf(&arg, "--%s-batch=%s", r_or_w, batch_prefix) < 0)
-			goto oom;
-		args[ac++] = arg;
-	}
-
 	if (io_timeout) {
 		if (asprintf(&arg, "--timeout=%d", io_timeout) < 0)
 			goto oom;
--- orig/pipe.c	2004-06-18 16:00:09
+++ pipe.c	2004-07-03 20:20:27
@@ -26,6 +26,7 @@ extern int am_server;
 extern int blocking_io;
 extern int orig_umask;
 extern int read_batch;
+extern int write_batch;
 extern int filesfrom_fd;
 
 /**
@@ -117,6 +118,13 @@ pid_t local_child(int argc, char **argv,
 		am_sender = read_batch ? 0 : !am_sender;
 		am_server = 1;
 
+		/* There is write_batch code on both the receiver and
+		 * sender sides.  In local_child, both are local processes,
+		 * so we must make sure that only one actually writes.  It
+		 * shouldn't matter which one -- here we prevent the server
+		 * from writing. */
+		write_batch = 0;
+
 		if (!am_sender)
 			filesfrom_fd = -1;
 
--- orig/receiver.c	2004-07-02 18:23:01
+++ receiver.c	2004-07-03 20:20:27
@@ -46,6 +46,7 @@ extern int cleanup_got_literal;
 extern int module_id;
 extern int ignore_errors;
 extern int orig_umask;
+extern int write_batch;
 extern int keep_partial;
 extern int checksum_seed;
 
@@ -277,6 +278,8 @@ static int receive_data(int f_in,struct 
 	sum_end(file_sum1);
 
 	read_buf(f_in,file_sum2,MD4_SUM_LENGTH);
+	if (write_batch)
+		write_batch_delta_file(file_sum2, MD4_SUM_LENGTH);
 	if (verbose > 2)
 		rprintf(FINFO,"got file_sum\n");
 	if (fd != -1 && memcmp(file_sum1, file_sum2, MD4_SUM_LENGTH) != 0)
@@ -329,6 +332,9 @@ int recv_files(int f_in,struct file_list
 			continue;
 		}
 
+		if (write_batch)
+			write_batch_delta_file((char *) &i, sizeof i);
+
 		if (i < 0 || i >= flist->count) {
 			rprintf(FERROR,"Invalid file index %d in recv_files (count=%d)\n",
 				i, flist->count);
--- orig/token.c	2004-06-18 16:20:45
+++ token.c	2004-07-03 20:20:27
@@ -80,6 +80,8 @@ static int simple_recv_token(int f,char 
 
 	if (residue == 0) {
 		int i = read_int(f);
+		if (write_batch)
+		        write_batch_delta_file((char *) &i, sizeof(int));
 		if (i <= 0)
 			return i;
 		residue = i;
@@ -89,6 +91,8 @@ static int simple_recv_token(int f,char 
 	n = MIN(CHUNK_SIZE,residue);
 	residue -= n;
 	read_buf(f,buf,n);
+	if (write_batch)
+	        write_batch_delta_file(buf, n);
 	return n;
 }