kernel32/path: Potential off-by-one error, help needed!

[Kirill Smirnov]

Hi!

    While debugging bug #33307 
(http://bugs.winehq.org/show_bug.cgi?id=33307) I found a suspicious 
piece of code, looking like off-by-one error.

    Unfortunately, I'm not familiar with this part of wine and I don't 
know how to write corresponding test case.

    If you familiar with this module, please, take a look at this 
wanna-be-a-bug and the proposed patch.

--
Kirill


diff --git a/dlls/kernel32/path.c b/dlls/kernel32/path.c
index 63d977b..7d0dc35 100644
--- a/dlls/kernel32/path.c
+++ b/dlls/kernel32/path.c
@@ -205,8 +205,12 @@ static BOOL add_boot_rename_entry( LPCWSTR source, LPCWSTR 
dest, DWORD flags )
     if (dest)
     {
         if (flags & MOVEFILE_REPLACE_EXISTING)
+        {
             *p++ = '!';
-        memcpy( p, dest_name.Buffer, len2 );
+            memcpy( p, dest_name.Buffer, len2 - sizeof(WCHAR) );
+        }
+        else
+            memcpy( p, dest_name.Buffer, len2 );
         DataSize += len2;
     }
     else