From aa2893a132880e454e8d69ae2251f213460673db Mon Sep 17 00:00:00 2001
From: Alex Ionescu <aionescu@gmail.com>
Date: Wed, 9 Nov 2005 01:39:39 +0000
Subject: [PATCH] - Implement RtlRealPrecessdor and RtlRealSuccessor

svn path=/trunk/; revision=19081
---
 reactos/lib/rtl/splaytree.c | 57 ++++++++++++++++++++++++++++---------
 1 file changed, 44 insertions(+), 13 deletions(-)

diff --git a/reactos/lib/rtl/splaytree.c b/reactos/lib/rtl/splaytree.c
index 7b45d8da5ed..ab81a43eb66 100644
--- a/reactos/lib/rtl/splaytree.c
+++ b/reactos/lib/rtl/splaytree.c
@@ -41,31 +41,62 @@ RtlDeleteNoSplay (
 	UNIMPLEMENTED;
 }
 
-
 /*
-* @unimplemented
+* @implemented
 */
 PRTL_SPLAY_LINKS
 NTAPI
-RtlRealPredecessor (
-	PRTL_SPLAY_LINKS Links
-	)
+RtlRealPredecessor(PRTL_SPLAY_LINKS Links)
 {
-	UNIMPLEMENTED;
-	return 0;
+    PRTL_SPLAY_LINKS Child;
+
+    /* Get the left child */
+    Child = RtlLeftChild(Links);
+    if (Child)
+    {
+        /* Get right-most child */
+        while (RtlRightChild(Child)) Child = RtlRightChild(Child);
+        return Child;
+    }
+
+    /* We don't have a left child, keep looping until we find our parent */
+    Child = Links;
+    while (RtlIsLeftChild(Child)) Child = RtlParent(Child);
+
+    /* The parent should be a right child, return the real predecessor */
+    if (RtlIsRightChild(Child)) return RtlParent(Child);
+
+    /* The parent isn't a right child, so no real precessor for us */
+    return NULL;
 }
 
 /*
-* @unimplemented
+* @implemented
 */
 PRTL_SPLAY_LINKS
 NTAPI
-RtlRealSuccessor (
-	PRTL_SPLAY_LINKS Links
-	)
+RtlRealSuccessor(PRTL_SPLAY_LINKS Links)
 {
-	UNIMPLEMENTED;
-	return 0;
+    PRTL_SPLAY_LINKS Child;
+
+    /* Get the right child */
+    Child = RtlRightChild(Links);
+    if (Child)
+    {
+        /* Get left-most child */
+        while (RtlLeftChild(Child)) Child = RtlLeftChild(Child);
+        return Child;
+    }
+
+    /* We don't have a right child, keep looping until we find our parent */
+    Child = Links;
+    while (RtlIsRightChild(Child)) Child = RtlParent(Child);
+
+    /* The parent should be a left child, return the real successor */
+    if (RtlIsLeftChild(Child)) return RtlParent(Child);
+
+    /* The parent isn't a right child, so no real successor for us */
+    return NULL;
 }
 
 /*