diff --git a/libisofs/branches/thomas/Makefile.am b/libisofs/branches/thomas/Makefile.am
index f992d25c..6101ec9c 100644
--- a/libisofs/branches/thomas/Makefile.am
+++ b/libisofs/branches/thomas/Makefile.am
@@ -55,6 +55,8 @@ libisofs_libisofs_la_SOURCES = \
 	libisofs/iso1999.h \
 	libisofs/iso1999.c \
 	libisofs/data_source.c
+libisofs_libisofs_la_LIBADD= \
+	$(THREAD_LIBS)
 libinclude_HEADERS = \
 	libisofs/libisofs.h
 
diff --git a/libisofs/branches/thomas/libisofs/find.c b/libisofs/branches/thomas/libisofs/find.c
index 02881130..797ef881 100644
--- a/libisofs/branches/thomas/libisofs/find.c
+++ b/libisofs/branches/thomas/libisofs/find.c
@@ -93,13 +93,20 @@ int find_iter_remove(IsoDirIter *iter)
     return iso_dir_iter_remove(data->iter);
 }
 
+void find_notify_child_taken(IsoDirIter *iter, IsoNode *node)
+{
+    /* nothing to do */
+    return;
+}
+
 static
 struct iso_dir_iter_iface find_iter_class = {
         find_iter_next,
         find_iter_has_next,
         find_iter_free,
         find_iter_take,
-        find_iter_remove
+        find_iter_remove,
+        find_notify_child_taken
 };
 
 int iso_dir_find_children(IsoDir* dir, IsoFindCondition *cond, 
@@ -134,6 +141,11 @@ int iso_dir_find_children(IsoDir* dir, IsoFindCondition *cond,
     data->iter = children;
     data->cond = cond;
     it->data = data;
+    
+    if (iso_dir_iter_register(it) < 0) {
+        free(it);
+        return ISO_OUT_OF_MEM;
+    }
 
     *iter = it;
     return ISO_SUCCESS;
diff --git a/libisofs/branches/thomas/libisofs/libisofs.h b/libisofs/branches/thomas/libisofs/libisofs.h
index a48666d7..a5bd199b 100644
--- a/libisofs/branches/thomas/libisofs/libisofs.h
+++ b/libisofs/branches/thomas/libisofs/libisofs.h
@@ -2731,6 +2731,35 @@ void iso_tree_set_report_callback(IsoImage *image,
 int iso_tree_add_node(IsoImage *image, IsoDir *parent, const char *path,
                       IsoNode **node);
 
+/**
+ * Add a new node to the image tree, from an existing file, and with the
+ * given name, that must not exist on dir.
+ * 
+ * @param image
+ *      The image
+ * @param parent
+ *      The directory in the image tree where the node will be added.
+ * @param name
+ *      The name that the node will have on image.
+ * @param path
+ *      The path of the file to add in the filesystem.
+ * @param node
+ *      place where to store a pointer to the newly added file. No 
+ *      extra ref is addded, so you will need to call iso_node_ref() if you 
+ *      really need it. You can pass NULL in this parameter if you don't need 
+ *      the pointer.
+ * @return
+ *     number of nodes in parent if success, < 0 otherwise
+ *     Possible errors:
+ *         ISO_NULL_POINTER, if image, parent or path are NULL
+ *         ISO_NODE_NAME_NOT_UNIQUE, a node with same name already exists
+ *         ISO_OUT_OF_MEM
+ * 
+ * @since 0.6.4
+ */
+int iso_tree_add_new_node(IsoImage *image, IsoDir *parent, const char *name, 
+                          const char *path, IsoNode **node);
+
 /**
  * Add the contents of a dir to a given directory of the iso tree.
  * 
diff --git a/libisofs/branches/thomas/libisofs/node.c b/libisofs/branches/thomas/libisofs/node.c
index 22f46d73..95a0095e 100644
--- a/libisofs/branches/thomas/libisofs/node.c
+++ b/libisofs/branches/thomas/libisofs/node.c
@@ -485,6 +485,10 @@ int iso_node_take(IsoNode *node)
         /* should never occur */
         return ISO_ASSERT_FAILURE;
     }
+    
+    /* notify iterators just before remove */
+    iso_notify_dir_iters(node, 0); 
+    
     *pos = node->next;
     node->parent = NULL;
     node->next = NULL;
@@ -531,7 +535,6 @@ static
 int iter_take(IsoDirIter *iter)
 {
     struct dir_iter_data *data;
-    IsoNode *pos, *pre;
     if (iter == NULL) {
         return ISO_NULL_POINTER;
     }
@@ -549,38 +552,7 @@ int iter_take(IsoDirIter *iter)
     /* clear next flag */
     data->flag &= ~0x01;
     
-    pos = iter->dir->children;
-    pre = NULL;
-    while (pos != NULL && pos != data->pos) {
-        pre = pos;
-        pos = pos->next;
-    }
-    if (pos == NULL) {
-        return ISO_ERROR; /* node not in dir */
-    }
-    
-    if (pos != data->pos) {
-        return ISO_ASSERT_FAILURE;
-    }
-    
-    /* dispose iterator reference */
-    iso_node_unref(data->pos);
-    
-    if (pre == NULL) {
-        /* node is a first position */
-        iter->dir->children = pos->next;
-        data->pos = NULL;
-    } else {
-        pre->next = pos->next;
-        data->pos = pre;
-        iso_node_ref(pre); /* take iter ref */
-    }
-    
-    /* take pos */
-    pos->parent = NULL;
-    pos->next = NULL;
-    iter->dir->nchildren--;
-    return ISO_SUCCESS;
+    return iso_node_take(data->pos);
 }
 
 static
@@ -601,19 +573,49 @@ int iter_remove(IsoDirIter *iter)
         /* remove node */
         iso_node_unref(pos);
     }
-    if (data->pos == pos) {
-        return ISO_ERROR;
-    }
     return ret;
 }
 
+void iter_notify_child_taken(IsoDirIter *iter, IsoNode *node)
+{
+    IsoNode *pos, *pre;
+    struct dir_iter_data *data;
+    data = iter->data;
+    
+    if (data->pos == node) { 
+        pos = iter->dir->children;
+        pre = NULL;
+        while (pos != NULL && pos != data->pos) {
+            pre = pos;
+            pos = pos->next;
+        }
+        if (pos == NULL || pos != data->pos) {
+            return;
+        }
+        
+        /* dispose iterator reference */
+        iso_node_unref(data->pos);
+        
+        if (pre == NULL) {
+            /* node is a first position */
+            iter->dir->children = pos->next;
+            data->pos = NULL;
+        } else {
+            pre->next = pos->next;
+            data->pos = pre;
+            iso_node_ref(pre); /* take iter ref */
+        }
+    }
+}
+
 static
 struct iso_dir_iter_iface iter_class = {
         iter_next,
         iter_has_next,
         iter_free,
         iter_take,
-        iter_remove
+        iter_remove,
+        iter_notify_child_taken
 };
 
 int iso_dir_get_children(const IsoDir *dir, IsoDirIter **iter)
@@ -639,6 +641,11 @@ int iso_dir_get_children(const IsoDir *dir, IsoDirIter **iter)
     data->pos = NULL;
     data->flag = 0x00;
     it->data = data;
+    
+    if (iso_dir_iter_register(it) < 0) {
+        free(it);
+        return ISO_OUT_OF_MEM;
+    }
 
     *iter = it;
     return ISO_SUCCESS;
@@ -663,6 +670,7 @@ int iso_dir_iter_has_next(IsoDirIter *iter)
 void iso_dir_iter_free(IsoDirIter *iter)
 {
     if (iter != NULL) {
+        iso_dir_iter_unregister(iter);
         iter->class->free(iter);
         free(iter);
     }
@@ -970,6 +978,63 @@ int iso_dir_insert(IsoDir *dir, IsoNode *node, IsoNode **pos,
     return ++dir->nchildren;
 }
 
+/* iterators are stored in a linked list */
+struct iter_reg_node {
+    IsoDirIter *iter;
+    struct iter_reg_node *next;
+};
+
+/* list header */
+static
+struct iter_reg_node *iter_reg = NULL;
+
+/**
+ * Add a new iterator to the registry. The iterator register keeps track of
+ * all iterators being used, and are notified when directory structure 
+ * changes.
+ */
+int iso_dir_iter_register(IsoDirIter *iter)
+{
+    struct iter_reg_node *new;
+    new = malloc(sizeof(struct iter_reg_node));
+    if (new == NULL) {
+        return ISO_OUT_OF_MEM;
+    }
+    new->iter = iter;
+    new->next = iter_reg;
+    iter_reg = new;
+    return ISO_SUCCESS;
+}
+
+/**
+ * Unregister a directory iterator.
+ */
+void iso_dir_iter_unregister(IsoDirIter *iter)
+{
+    struct iter_reg_node **pos;
+    pos = &iter_reg;
+    while (*pos != NULL && (*pos)->iter != iter) {
+        pos = &(*pos)->next;
+    }
+    if (*pos) {
+        struct iter_reg_node *tmp = (*pos)->next;
+        free(*pos);
+        *pos = tmp;
+    }
+}
+
+void iso_notify_dir_iters(IsoNode *node, int flag) 
+{
+    struct iter_reg_node *pos = iter_reg;
+    while (pos != NULL) {
+        IsoDirIter *iter = pos->iter;
+        if (iter->dir == node->parent) {
+            iter->class->notify_child_taken(iter, node);
+        }
+        pos = pos->next;
+    }
+}
+
 int iso_node_new_root(IsoDir **root)
 {
     IsoDir *dir;
diff --git a/libisofs/branches/thomas/libisofs/node.h b/libisofs/branches/thomas/libisofs/node.h
index a1fc96d3..dd13469f 100644
--- a/libisofs/branches/thomas/libisofs/node.h
+++ b/libisofs/branches/thomas/libisofs/node.h
@@ -161,6 +161,11 @@ struct iso_dir_iter_iface
 
     int (*remove)(IsoDirIter *iter);
     
+    /** 
+     * This is called just before remove a node from a directory. The iterator
+     * may want to update its internal state according to this.
+     */
+    void (*notify_child_taken)(IsoDirIter *iter, IsoNode *node);
 };
 
 /**
@@ -322,4 +327,18 @@ int iso_dir_exists(IsoDir *dir, const char *name, IsoNode ***pos);
 int iso_dir_insert(IsoDir *dir, IsoNode *node, IsoNode **pos, 
                    enum iso_replace_mode replace);
 
+/**
+ * Add a new iterator to the registry. The iterator register keeps track of
+ * all iterators being used, and are notified when directory structure 
+ * changes.
+ */
+int iso_dir_iter_register(IsoDirIter *iter);
+
+/**
+ * Unregister a directory iterator.
+ */
+void iso_dir_iter_unregister(IsoDirIter *iter);
+
+void iso_notify_dir_iters(IsoNode *node, int flag);
+
 #endif /*LIBISO_NODE_H_*/
diff --git a/libisofs/branches/thomas/libisofs/tree.c b/libisofs/branches/thomas/libisofs/tree.c
index 5dc360ed..420b6113 100644
--- a/libisofs/branches/thomas/libisofs/tree.c
+++ b/libisofs/branches/thomas/libisofs/tree.c
@@ -475,6 +475,59 @@ int iso_tree_add_node(IsoImage *image, IsoDir *parent, const char *path,
     return result;
 }
 
+int iso_tree_add_new_node(IsoImage *image, IsoDir *parent, const char *name, 
+                          const char *path, IsoNode **node)
+{
+    int result;
+    IsoFilesystem *fs;
+    IsoFileSource *file;
+    IsoNode *new;
+    IsoNode **pos;
+
+    if (image == NULL || parent == NULL || name == NULL || path == NULL) {
+        return ISO_NULL_POINTER;
+    }
+
+    if (node) {
+        *node = NULL;
+    }
+
+    fs = image->fs;
+    result = fs->get_by_path(fs, path, &file);
+    if (result < 0) {
+        return result;
+    }
+
+    /* find place where to insert */
+    result = iso_dir_exists(parent, name, &pos);
+    if (result) {
+        /* a node with same name already exists */
+        iso_file_source_unref(file);
+        return ISO_NODE_NAME_NOT_UNIQUE;
+    }
+
+    result = image->builder->create_node(image->builder, image, file, &new);
+    if (result < 0) {
+        return result;
+    }
+    
+    /* free the file */
+    iso_file_source_unref(file);
+    
+    result = iso_node_set_name(new, name);
+    if (result < 0) {
+        iso_node_unref(new);
+        return result;
+    }
+
+    if (node) {
+        *node = new;
+    }
+
+    /* finally, add node to parent */
+    return iso_dir_insert(parent, new, pos, ISO_REPLACE_NEVER);
+}
+
 static
 int check_excludes(IsoImage *image, const char *path)
 {