--- xbsql/xbsql.cpp~	2012-09-16 12:35:05.000000000 +0200
+++ xbsql/xbsql.cpp	2012-09-16 12:40:28.465720698 +0200
@@ -468,7 +468,7 @@
 		char	name[256]	;
 
 		strncpy	(name, table,			sizeof(name)) ;
-		strncat	(name, "_",			sizeof(name)) ;
+		strncat	(name, "_",			sizeof(name) -strlen(name) -1) ;
 		strncat	(name, fSet.getFieldName (idx),	sizeof(name)) ;
 
 		path	= getPath (name, "ndx") ;
@@ -874,10 +874,10 @@
 			const char	*fname	= fSet.getFieldName (idx) ;
 
 			strncpy	(_oldName, oldName, sizeof(_oldName)) ;
-			strncat	(_oldName, "_",     sizeof(_oldName)) ;
+			strncat	(_oldName, "_",     sizeof(_oldName)- strlen(_oldName) -1) ;
 			strncat	(_oldName, fname,   sizeof(_oldName)) ;
 			strncpy	(_newName, newName, sizeof(_newName)) ;
-			strncat	(_newName, "_",	    sizeof(_newName)) ;
+			strncat	(_newName, "_",	    sizeof(_newName) - strlen(newName) - 1) ;
 			strncat	(_newName, fname,   sizeof(_newName)) ;
 
 			oldAnon	= getPath (_oldName, "ndx") ;