From d2e0015ab754df537470fa79b7991c9f7b040600 Mon Sep 17 00:00:00 2001
From: Eric Kohl <eric.kohl@reactos.org>
Date: Fri, 14 May 1999 13:30:07 +0000
Subject: [PATCH] Fixed overlapping buffer handling.

svn path=/trunk/; revision=465
---
 reactos/lib/crtdll/string/memmove.c | 36 +++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/reactos/lib/crtdll/string/memmove.c b/reactos/lib/crtdll/string/memmove.c
index d8af46e554b..3315e10d8c9 100644
--- a/reactos/lib/crtdll/string/memmove.c
+++ b/reactos/lib/crtdll/string/memmove.c
@@ -3,18 +3,34 @@
 
 void * memmove(void *dest,const void *src,size_t count)
 {
-	char *char_dest = (char *)dest;
-	char *char_src = (char *)src;
+    char *char_dest = (char *)dest;
+    char *char_src = (char *)src;
 
-	while(count > 0 )
+    if ((char_dest <= char_src) || (char_dest >= (char_src+count)))
+    {
+        /*  non-overlapping buffers */
+        while(count > 0)
 	{
-		*char_dest = *char_src;
-		char_dest++;
-		char_src++;
-		count--;
+            *char_dest = *char_src;
+            char_dest++;
+            char_src++;
+            count--;
 	}
+    }
+    else
+    {
+        /* overlaping buffers */
+        char_dest = (char *)dest + count - 1;
+        char_src = (char *)src + count - 1;
 
-	return dest;
-	
-	
+        while(count > 0)
+	{
+           *char_dest = *char_src;
+           char_dest--;
+           char_src--;
+           count--;
+	}
+    }
+
+    return dest;
 }