(cache_sync): Store the previous backup file.

src/server/dbck-cache.c

 /*
- * $Id: dbck-cache.c,v 0.33 1998/08/07 23:07:01 ceder Exp $
+ * $Id: dbck-cache.c,v 0.34 1998/10/11 17:20:01 ceder Exp $
  * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996  Lysator Academic Computer Association.
  *
  * This file is part of the LysKOM server.
@@ -33,7 +33,7 @@
  */
 
 static const char *
-rcsid = "$Id: dbck-cache.c,v 0.33 1998/08/07 23:07:01 ceder Exp $";
+rcsid = "$Id: dbck-cache.c,v 0.34 1998/10/11 17:20:01 ceder Exp $";
 #include "rcs.h"
 USE(rcsid);
 
@@ -581,6 +581,15 @@ cache_sync(void)
 
     if ( is_clean(param.datafile_name) )
     {
+	if (is_clean(param.backupfile_name))
+	{
+	    if (rename(param.backupfile_name,
+		       param.backupfile_name_2) != 0)
+	    {
+		log("pre_sync: can't do extra backup.\n");
+	    }
+	}
+
 	if ( rename(param.datafile_name, param.backupfile_name) != 0 )
 	    log("WARNING: cache_sync: can't backup.\n");
     }