diff --git a/libisofs/trunk/CONTRIBUTORS b/libisofs/trunk/CONTRIBUTORS
index c774a038..7c150504 100644
--- a/libisofs/trunk/CONTRIBUTORS
+++ b/libisofs/trunk/CONTRIBUTORS
@@ -1,2 +1,3 @@
 Joe Neeman
 Philippe Rouquier 
+David Mohr
diff --git a/libisofs/trunk/libisofs/ecma119.c b/libisofs/trunk/libisofs/ecma119.c
index a1ac6810..f0f85484 100755
--- a/libisofs/trunk/libisofs/ecma119.c
+++ b/libisofs/trunk/libisofs/ecma119.c
@@ -7,6 +7,7 @@
 #include <time.h>
 #include <assert.h>
 #include <err.h>
+#include <stdarg.h>
 
 #include "ecma119.h"
 #include "ecma119_tree.h"
@@ -27,8 +28,6 @@ bs_get_size(struct burn_source *bs);
 static void
 bs_free_data(struct burn_source *bs);
 
-typedef void (*write_fn)(struct ecma119_write_target*, uint8_t*);
-
 /* return true if the given state is only required for Joliet volumes */
 static int
 is_joliet_state(enum ecma119_write_state);
@@ -42,15 +41,15 @@ write_data_chunk(struct ecma119_write_target *t, uint8_t *buf);
 
 /* writing functions. All these functions assume the buf is large enough */
 static void
-write_pri_vol_desc(struct ecma119_write_target *t, uint8_t *buf);
+write_pri_vol_desc(struct ecma119_write_target *t, uint8_t *buf, va_list params);
 static void
-write_vol_desc_terminator(struct ecma119_write_target *t, uint8_t *buf);
+write_vol_desc_terminator(struct ecma119_write_target *t, uint8_t *buf, va_list params);
 static void
 write_path_table(struct ecma119_write_target *t, int l_type, uint8_t *buf);
 static void
-write_l_path_table(struct ecma119_write_target *t, uint8_t *buf);
+write_l_path_table(struct ecma119_write_target *t, uint8_t *buf, va_list params);
 static void
-write_m_path_table(struct ecma119_write_target *t, uint8_t *buf);
+write_m_path_table(struct ecma119_write_target *t, uint8_t *buf, va_list params);
 static void
 write_one_dir_record(struct ecma119_write_target *t,
 		     struct ecma119_tree_node *dir,
@@ -61,7 +60,7 @@ write_one_dir(struct ecma119_write_target *t,
 	      struct ecma119_tree_node *dir,
 	      uint8_t *buf);
 static void
-write_dirs(struct ecma119_write_target *t, uint8_t *buf);
+write_dirs(struct ecma119_write_target *t, uint8_t *buf, va_list params);
 
 /* wrapper functions for writing */
 static void wr_system_area(struct ecma119_write_target*, uint8_t*);
@@ -72,7 +71,7 @@ static void wr_m_path_table(struct ecma119_write_target*, uint8_t*);
 static void wr_dir_records(struct ecma119_write_target*, uint8_t*);
 static void wr_files(struct ecma119_write_target*, uint8_t*);
 
-static const write_fn writers[] =
+static const write_fn_wrap writers[] =
 {
 	NULL,
 	wr_system_area,
@@ -391,7 +390,23 @@ wr_m_path_table(struct ecma119_write_target *t, uint8_t *buf)
 static void
 wr_dir_records(struct ecma119_write_target *t, uint8_t *buf)
 {
-	ecma119_start_chunking(t, write_dirs, t->total_dir_size, buf);
+	int i;
+	int j;
+	size_t size = 0;
+	size_t dir_size;
+	struct ecma119_tree_node *dir;
+	for (i = j = 0; j < t->dirlist_len; j++) {
+		dir = t->dirlist[j];
+		dir_size = dir->dir.len + dir->dir.CE_len;
+		if (size + dir_size > t->block_size) {
+			/* we are exceeding a logical block now,
+			 * so write all the directory records so far */
+			ecma119_start_chunking(t, write_dirs, size, buf, i, j-1);
+			i = j;
+			size = 0;
+		}
+		size += dir_size;
+	}
 }
 
 static void
@@ -427,7 +442,7 @@ wr_files(struct ecma119_write_target *t, uint8_t *buf)
 }
 
 static void
-write_pri_vol_desc(struct ecma119_write_target *t, uint8_t *buf)
+write_pri_vol_desc(struct ecma119_write_target *t, uint8_t *buf, va_list params)
 {
 	struct ecma119_pri_vol_desc *vol = (struct ecma119_pri_vol_desc*)buf;
 	struct iso_volume *volume = t->volset->volume[t->volnum];
@@ -469,7 +484,7 @@ write_pri_vol_desc(struct ecma119_write_target *t, uint8_t *buf)
 }
 
 static void
-write_vol_desc_terminator(struct ecma119_write_target *t, uint8_t *buf)
+write_vol_desc_terminator(struct ecma119_write_target *t, uint8_t *buf, va_list params)
 {
 	struct ecma119_vol_desc_terminator *vol =
 		(struct ecma119_vol_desc_terminator*) buf;
@@ -507,13 +522,13 @@ write_path_table(struct ecma119_write_target *t, int l_type, uint8_t *buf)
 }
 
 static void
-write_l_path_table(struct ecma119_write_target *t, uint8_t *buf)
+write_l_path_table(struct ecma119_write_target *t, uint8_t *buf, va_list params)
 {
 	write_path_table(t, 1, buf);
 }
 
 static void
-write_m_path_table(struct ecma119_write_target *t, uint8_t *buf)
+write_m_path_table(struct ecma119_write_target *t, uint8_t *buf, va_list params)
 {
 	write_path_table(t, 0, buf);
 }
@@ -597,14 +612,19 @@ write_one_dir(struct ecma119_write_target *t,
 }
 
 static void
-write_dirs(struct ecma119_write_target *t, uint8_t *buf)
+write_dirs(struct ecma119_write_target *t, uint8_t *buf, va_list params)
 {
-	size_t i;
+	int i,start,end;
 	struct ecma119_tree_node *dir;
-	for (i = 0; i < t->dirlist_len; i++) {
+	start = va_arg(params, int);
+	end = va_arg(params, int);
+	assert(start >= 0);
+	assert(end < t->dirlist_len);
+
+	for (i = start; i < end; i++) {
 		dir = t->dirlist[i];
 		write_one_dir(t, dir, buf);
-		buf += round_up(dir->dir.len + dir->dir.CE_len, t->block_size);
+		buf += dir->dir.len + dir->dir.CE_len;
 	}
 }
 
@@ -612,9 +632,13 @@ void
 ecma119_start_chunking(struct ecma119_write_target *t,
 	       write_fn writer,
 	       off_t data_size,
-	       uint8_t *buf)
+	       uint8_t *buf,
+	       ...)
 {
+	va_list params;
+	va_start(params, buf);
 	if (data_size != t->state_data_size) {
+		/* FIXME: are we sure that roundup works as expected? */
 		data_size = round_up(data_size, t->block_size);
 		t->state_data = realloc(t->state_data, data_size);
 		t->state_data_size = data_size;
@@ -622,8 +646,9 @@ ecma119_start_chunking(struct ecma119_write_target *t,
 	memset(t->state_data, 0, t->state_data_size);
 	t->state_data_off = 0;
 	t->state_data_valid = 1;
-	writer(t, t->state_data);
+	writer(t, t->state_data, params);
 	write_data_chunk(t, buf);
+	va_end(params);
 }
 
 static void
diff --git a/libisofs/trunk/libisofs/ecma119.h b/libisofs/trunk/libisofs/ecma119.h
index 79505509..0ff5eede 100755
--- a/libisofs/trunk/libisofs/ecma119.h
+++ b/libisofs/trunk/libisofs/ecma119.h
@@ -258,10 +258,14 @@ struct ecma119_path_table_record
  * rather than block-by-block. This creates a buffer of size \p size, passes
  * it to the given writer, then hands out block-sized chunks.
  */
+typedef void (*write_fn)(struct ecma119_write_target*, uint8_t*, va_list);
+typedef void (*write_fn_wrap)(struct ecma119_write_target*, uint8_t*);
+
 void
 ecma119_start_chunking(struct ecma119_write_target *t,
-		       void (*)(struct ecma119_write_target*, uint8_t*),
+		       write_fn writer,
 		       off_t size,
-		       uint8_t *buf);
+		       uint8_t *buf,
+		       ...);
 
 #endif /* LIBISO_ECMA119_H */