From 768f97c38e3c583372ad8f5642e88a0b2ebee04d Mon Sep 17 00:00:00 2001
From: Jonas Fonseca <fonseca@diku.dk>
Date: Mon, 16 Jan 2006 05:10:22 +0100
Subject: [PATCH] Add get_dom_node_prev() which gets the previous sibling of a
 DOM node

---
 src/dom/node.c | 35 ++++++++++++++++++++++++++++++-----
 src/dom/node.h |  3 +++
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/src/dom/node.c b/src/dom/node.c
index 7ac7e1b9d..8d86a7a19 100644
--- a/src/dom/node.c
+++ b/src/dom/node.c
@@ -225,16 +225,15 @@ get_dom_node_map_entry(struct dom_node_list *list, enum dom_node_type type,
 	return dom_node_list_bsearch(&search, list);
 }
 
-int
-get_dom_node_list_index(struct dom_node *parent, struct dom_node *node)
+static int
+get_dom_node_list_pos(struct dom_node_list *list, struct dom_node *node)
 {
-	struct dom_node_list **list = get_dom_node_list(parent, node);
 	struct dom_node *entry;
 	int i;
 
-	if (!list) return -1;
+	assert(list);
 
-	foreach_dom_node (*list, entry, i) {
+	foreach_dom_node (list, entry, i) {
 		if (entry == node)
 			return i;
 	}
@@ -242,6 +241,32 @@ get_dom_node_list_index(struct dom_node *parent, struct dom_node *node)
 	return -1;
 }
 
+int
+get_dom_node_list_index(struct dom_node *parent, struct dom_node *node)
+{
+	struct dom_node_list **list = get_dom_node_list(parent, node);
+
+	return list ? get_dom_node_list_pos(*list, node) : -1;
+}
+
+struct dom_node *
+get_dom_node_prev(struct dom_node *node)
+{
+	struct dom_node_list **list;
+	int index;
+
+	assert(node->parent);
+
+	list = get_dom_node_list(node->parent, node);
+	if (!list) return NULL;
+
+	index = get_dom_node_list_pos(*list, node);
+	if (index > 0)
+		return (*list)->entries[index - 1];
+
+	return NULL;
+}
+
 /* Nodes */
 
 struct dom_node *
diff --git a/src/dom/node.h b/src/dom/node.h
index 542b89301..3e5e94c8e 100644
--- a/src/dom/node.h
+++ b/src/dom/node.h
@@ -243,6 +243,9 @@ int get_dom_node_list_index(struct dom_node *parent, struct dom_node *node);
  * @list is already sorted properly. */
 int get_dom_node_map_index(struct dom_node_list *list, struct dom_node *node);
 
+/* Returns the previous sibling to the node. */
+struct dom_node *get_dom_node_prev(struct dom_node *node);
+
 /* Looks up the @node_map for a node matching the requested type and name.
  * The @subtype maybe be 0 indication unknown subtype and only name should be
  * tested else it will indicate either the element or attribute private