--- Libc/Libc-262/gen/setlogin.c
+++ Libc/Libc-997.90.3/gen/setlogin.c
@@ -1,21 +1,22 @@
 /*
- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
  * @APPLE_LICENSE_HEADER_END@
  */
@@ -54,10 +55,25 @@
 
 
 #include <unistd.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
 
-extern int _logname_valid;		/* shared with getlogin() */
+extern int __setlogin(const char* name);
+
+extern pthread_mutex_t __logname_mutex;
+extern char *__logname;
 
 int setlogin(const char* name)
 {
-	return (_logname_valid = _setlogin(name));
+	pthread_mutex_lock(&__logname_mutex);
+
+	int res = __setlogin(name);
+	if (res == 0 && __logname != NULL) {
+		__logname[0] = 0;
+	}
+
+	pthread_mutex_unlock(&__logname_mutex);
+
+	return res;
 }