[lasem] dom: full ownership transfer of new_child parameter.

[Emmanuel Pacaud <emmanuel src gnome org>]

commit f215ea62b59f2634815a152a9131f48ea1ed8d1d
Author: Emmanuel Pacaud <emmanuel gnome org>
Date:   Sun May 1 18:00:01 2011 +0200

    dom: full ownership transfer of new_child parameter.
    
    Unref the given object event if it is not actually inserted in
    the dom tree. This way, user doesn't have to pay attention of
    the returned value of append_child, insert_before and replace_child.

 src/lsmdomnode.c   |  144 +++++++++++++++++++++++++++++++++++++++++++++++----
 src/lsmdomparser.c |    8 +---
 2 files changed, 133 insertions(+), 19 deletions(-)
---
diff --git a/src/lsmdomnode.c b/src/lsmdomnode.c
index 1111733..242a3f1 100644
--- a/src/lsmdomnode.c
+++ b/src/lsmdomnode.c
@@ -300,19 +300,55 @@ lsm_dom_node_get_owner_document (LsmDomNode* self)
 	return LSM_DOM_DOCUMENT (parent);
 }
 
+/**
+ * lsm_dom_node_insert_before:
+ * @self: a #LsmDomNode
+ * @new_child: (transfer full): node to insert
+ * @ref_child: (transfer none): reference node, i.e., the node before which the new node must be inserted.
+ *
+ * Inserts the node @new_child before the existing child node @ref_child. If
+ * @ref_child is null, insert @new_child at the end of the list of children.
+ * If the @new_child is already in the tree, it is first removed.
+ *
+ * returns: (transfer none): the inserted node.
+ */
+
+/* TODO:
+ * If @new_child is a #LsmDocumentFragment object, all of its children are inserted,
+ * in the same order, before @ref_child. 
+ * Check if new_child is an ancestor of self.
+ */
+
 LsmDomNode*
 lsm_dom_node_insert_before (LsmDomNode* self, LsmDomNode* new_child, LsmDomNode* ref_child)
 {
 	LsmDomNodeClass *node_class;
 
-	g_return_val_if_fail (LSM_IS_DOM_NODE (self), NULL);
+	if (ref_child == NULL)
+		lsm_dom_node_append_child (self, new_child);
+
 	g_return_val_if_fail (LSM_IS_DOM_NODE (new_child), NULL);
-	g_return_val_if_fail (LSM_IS_DOM_NODE (ref_child), NULL);
+
+	if (new_child->parent_node != NULL)
+		lsm_dom_node_remove_child (self, new_child);
+
+	if (!LSM_IS_DOM_NODE (self)) {
+		g_critical ("%s: self is not a LsmDomNode", G_STRFUNC);
+		g_object_unref (new_child);
+		return NULL;
+	}
+
+	if (!LSM_IS_DOM_NODE (ref_child)) {
+		g_critical ("%s: ref_child is not a LsmDomNode", G_STRFUNC);
+		g_object_unref (new_child);
+		return NULL;
+	}
 
 	if (ref_child->parent_node != self) {
 		lsm_debug ("dom", "[LsmDomNode::insert_before] Ref child '%s' doesn't belong to '%s'",
 			   lsm_dom_node_get_node_name (ref_child),
 			   lsm_dom_node_get_node_name (self));
+		g_object_unref (new_child);
 		return NULL;
 	}
 
@@ -320,6 +356,7 @@ lsm_dom_node_insert_before (LsmDomNode* self, LsmDomNode* new_child, LsmDomNode*
 		lsm_debug ("dom", "[LsmDomNode::insert_before] Can't append '%s' to '%s'",
 			   lsm_dom_node_get_node_name (new_child),
 			   lsm_dom_node_get_node_name (self));
+		g_object_unref (new_child);
 		return NULL;
 	}
 
@@ -344,28 +381,75 @@ lsm_dom_node_insert_before (LsmDomNode* self, LsmDomNode* new_child, LsmDomNode*
 	return new_child;
 }
 
+/**
+ * lsm_dom_node_replace_child:
+ * @self: a #LsmDomNode
+ * @new_child: (transfer full): a replacement node
+ * @old_child: (transfer none): node to replace
+ *
+ * Replaces the child node @old_child with @new_child in the list of children,
+ * and returns the @old_child node.
+ * If the @new_child is already in the tree, it is first removed.
+ *
+ * returns: (transfer full): the replaced node.
+ */
+
+/* TODO:
+ * Check if new_child is an ancestor of self.
+ */
+
 LsmDomNode*
 lsm_dom_node_replace_child (LsmDomNode* self, LsmDomNode* new_child, LsmDomNode* old_child)
 {
 	LsmDomNode *next_sibling;
 	LsmDomNode *node;
 
-	g_return_val_if_fail (LSM_IS_DOM_NODE (self), NULL);
-	g_return_val_if_fail (LSM_IS_DOM_NODE (old_child), NULL);
+	if (new_child == NULL)
+		return lsm_dom_node_remove_child (self, old_child);
 
-	if (old_child->parent_node != self)
+	if (!LSM_IS_DOM_NODE (new_child)) {
+		g_critical ("%s: new_child is not a LsmDomNode", G_STRFUNC);
+		if (LSM_IS_DOM_NODE (old_child))
+			g_object_unref (old_child);
 		return NULL;
+	}
 
-	next_sibling = old_child->next_sibling;
+	if (new_child->parent_node != NULL)
+		lsm_dom_node_remove_child (self, new_child);
 
-	node = lsm_dom_node_remove_child (self, old_child);
-	if (node != old_child)
+	if (old_child == NULL) {
+		lsm_debug ("dom", "[LsmDomNode::replace_child] old_child == NULL)");
+		g_object_unref (new_child);
 		return NULL;
+	}
 
-	if (new_child == NULL)
+	if (!LSM_IS_DOM_NODE (old_child)) {
+		g_critical ("%s: old_child is not a LsmDomNode", G_STRFUNC);
+		g_object_unref (new_child);
+		return NULL;
+	}
+
+	if (!LSM_IS_DOM_NODE (self)) {
+		g_critical ("%s: self is not a LsmDomNode", G_STRFUNC);
+		g_object_unref (new_child);
+		g_object_unref (old_child);
 		return NULL;
+	}
 
-	g_return_val_if_fail (LSM_IS_DOM_NODE (new_child), NULL);
+	if (old_child->parent_node != self) {
+		g_object_unref (new_child);
+		g_object_unref (old_child);
+		return NULL;
+	}
+
+	next_sibling = old_child->next_sibling;
+
+	node = lsm_dom_node_remove_child (self, old_child);
+	if (node != old_child) {
+		g_object_unref (new_child);
+		g_object_unref (old_child);
+		return NULL;
+	}
 
 	if (next_sibling == NULL)
 		lsm_dom_node_append_child (self, new_child);
@@ -375,6 +459,16 @@ lsm_dom_node_replace_child (LsmDomNode* self, LsmDomNode* new_child, LsmDomNode*
 	return old_child;
 }
 
+/**
+ * lsm_dom_node_remove_child:
+ * @self: a #LsmDomNode
+ * @old_child: (transfer none): node to remove.
+ *
+ * Removes the child node indicated by @old_child from the list of children, and returns it.
+ *
+ * returns: (transfer full): the removed node.
+ */
+
 LsmDomNode*
 lsm_dom_node_remove_child (LsmDomNode* self, LsmDomNode* old_child)
 {
@@ -382,6 +476,10 @@ lsm_dom_node_remove_child (LsmDomNode* self, LsmDomNode* old_child)
 	LsmDomNodeClass *node_class;
 
 	g_return_val_if_fail (LSM_IS_DOM_NODE (self), NULL);
+
+	if (old_child == NULL)
+		return NULL;
+
 	g_return_val_if_fail (LSM_IS_DOM_NODE (old_child), NULL);
 
 	for (node = self->first_child;
@@ -415,19 +513,41 @@ lsm_dom_node_remove_child (LsmDomNode* self, LsmDomNode* old_child)
 	return old_child;
 }
 
+/**
+ * lsm_dom_node_append_child:
+ * @self: a #LsmDomNode
+ * @new_child: (transfer full): node to append
+ *
+ * Adds the node @new_child to the end of the list of children of this node.
+ * If the @new_child is already in the tree, it is first removed.
+ *
+ * returns: (transfer none): the added node.
+ */
+
 LsmDomNode *
 lsm_dom_node_append_child (LsmDomNode* self, LsmDomNode* new_child)
 {
 	LsmDomNodeClass *node_class;
 
-	g_return_val_if_fail (LSM_IS_DOM_NODE (self), NULL);
+	if (new_child == NULL)
+		return NULL;
+
 	g_return_val_if_fail (LSM_IS_DOM_NODE (new_child), NULL);
-	g_return_val_if_fail (new_child->parent_node == NULL, NULL);
+
+	if (!LSM_IS_DOM_NODE (self)) {
+		g_critical ("%s: self is not a LsmDomNode", G_STRFUNC);
+		g_object_unref (new_child);
+		return NULL;
+	}
+
+	if (new_child->parent_node != NULL)
+		lsm_dom_node_remove_child (self, new_child);
 
 	if (!LSM_DOM_NODE_GET_CLASS (self)->can_append_child (self, new_child)) {
 		lsm_debug ("dom", "[LsmDomNode::append_child] Can't append '%s' to '%s'",
 			   lsm_dom_node_get_node_name (new_child),
 			   lsm_dom_node_get_node_name (self));
+		g_object_unref (new_child);
 		return NULL;
 	}
 
diff --git a/src/lsmdomparser.c b/src/lsmdomparser.c
index 1842379..56ae64b 100644
--- a/src/lsmdomparser.c
+++ b/src/lsmdomparser.c
@@ -116,9 +116,6 @@ lsm_dom_parser_start_element(void *user_data,
 		state->is_error = FALSE;
 		state->error_depth = 0;
 	} else {
-		if (node != NULL)
-			g_object_unref (node);
-
 		state->is_error = TRUE;
 		state->error_depth = 1;
 	}
@@ -155,10 +152,7 @@ lsm_dom_parser_characters (void *user_data, const xmlChar *ch, int len)
 		text = g_strndup ((char *) ch, len);
 		node = LSM_DOM_NODE (lsm_dom_document_create_text_node (LSM_DOM_DOCUMENT (state->document), text));
 
-		if (lsm_dom_node_append_child (state->current_node, node) == NULL) {
-			if (node != NULL)
-				g_object_unref (node);
-		}
+		lsm_dom_node_append_child (state->current_node, node);
 
 		g_free (text);
 	}