add xmlThrDefMutex = NULL in xmlCleanupGlobals() as suggested by Rob

* globals.c: add xmlThrDefMutex = NULL in xmlCleanupGlobals()
  as suggested by Rob Richards
Daniel
diff --git a/ChangeLog b/ChangeLog
index 52f799a..26107df 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jul 15 22:03:13 CEST 2003 Daniel Veillard <daniel@veillard.com>
+
+	* globals.c: add xmlThrDefMutex = NULL in xmlCleanupGlobals() 
+	  as suggested by Rob Richards
+
 Tue Jul 15 15:30:55 CEST 2003 Daniel Veillard <daniel@veillard.com>
 
 	* DOCBparser.c HTMLparser.c entities.c parser.c relaxng.c 
diff --git a/globals.c b/globals.c
index 811160f..9c1b1d2 100644
--- a/globals.c
+++ b/globals.c
@@ -46,8 +46,10 @@
 
 void xmlCleanupGlobals()
 {
-    if (xmlThrDefMutex != NULL)
+    if (xmlThrDefMutex != NULL) {
 	xmlFreeMutex(xmlThrDefMutex);
+	xmlThrDefMutex = NULL;
+    }
 }
 
 /************************************************************************