From: Daniel Drake <dsd@gentoo.org>

Two threads could obtain the same lock as Obtain() does not check if the file
it is creating already exists.

This is most likely the result of a porting thinko, the corresponding java
method fails if the file it wants to create already exists, whereas the C#
version silently overwrites the existing file.

--- Lucene.Net.Orig/Store/FSDirectory.cs	2005-10-03 21:01:30.000000000 +0100
+++ Lucene.Net/Store/FSDirectory.cs	2005-10-03 21:02:32.000000000 +0100
@@ -71,7 +71,10 @@ namespace Lucene.Net.Store
 						throw new System.IO.IOException("Cannot create lock directory: " + Enclosing_Instance.lockDir);
 					}
 				}
-				
+
+				if (System.IO.File.Exists(lockFile.FullName))
+					return false;
+
                 try
                 {
                     System.IO.FileStream createdFile = lockFile.Create();
@@ -761,4 +764,4 @@ namespace Lucene.Net.Store
 			file.Close(); // close the file
 		}
 	}
-}
\ No newline at end of file
+}