From 3c024e7b3170bd2d3869a404b08bc20345bc6f81 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Sun, 2 Oct 2011 21:36:21 +0200
Subject: [PATCH] add a new vlist flag for avoiding automatic delete of entries

---
 utils.c | 5 +++--
 utils.h | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/utils.c b/utils.c
index cc22290..31a5967 100644
--- a/utils.c
+++ b/utils.c
@@ -21,7 +21,8 @@ __vlist_init(struct vlist_tree *tree, avl_tree_comp cmp,
 void
 vlist_delete(struct vlist_tree *tree, struct vlist_node *node)
 {
-	avl_delete(&tree->avl, &node->avl);
+	if (!tree->no_delete)
+		avl_delete(&tree->avl, &node->avl);
 	tree->update(tree, NULL, node);
 }
 
@@ -37,7 +38,7 @@ vlist_add(struct vlist_tree *tree, struct vlist_node *node)
 
 	anode = avl_find(&tree->avl, key);
 	if (anode) {
-		if (tree->keep_old)
+		if (tree->keep_old || !tree->no_delete)
 			goto update_only;
 
 		old_node = container_of(anode, struct vlist_node, avl);
diff --git a/utils.h b/utils.h
index d71a8f7..8ef968a 100644
--- a/utils.h
+++ b/utils.h
@@ -29,6 +29,7 @@ struct vlist_tree {
 	vlist_update_cb update;
 	int key_offset;
 	bool keep_old;
+	bool no_delete;
 
 	int version;
 };
-- 
2.11.0