Index: H5Fint.c
===================================================================
--- H5Fint.c	(revision 154117)
+++ H5Fint.c	(working copy)
@@ -888,6 +888,7 @@
     if(H5FO_top_dest(f) < 0)
         HDONE_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "problems closing file")
     f->shared = NULL;
+    memset(f, 0xCD, sizeof(H5F_t)); // trip dangling references early!
     f = H5FL_FREE(H5F_t, f);
 
     FUNC_LEAVE_NOAPI(ret_value)