fix NULL when accessing instances of read_steer

v2.6/toolkit/fastnlotoolkit/include/fastnlotk/read_steer.h

@@ -597,15 +597,19 @@ public:
       return read_steer::Steering(steerID)->getstcol(label,column); }
    // check existence of value
    static bool getexist(const std::string& label, std::string steerID=read_steer::stdID ){
+      if ( read_steer::instances==NULL ) read_steer::instances = new std::map<string,read_steer*>();
       if ( read_steer::instances->count(steerID) == 0 ) return false;
       return read_steer::Steering(steerID)->exist(label);}
    static bool getarrayexist(const std::string& label, std::string steerID=read_steer::stdID ){
+      if ( read_steer::instances==NULL ) read_steer::instances = new std::map<string,read_steer*>();
       if ( read_steer::instances->count(steerID) == 0 ) return false;
       return read_steer::Steering(steerID)->arrayexist(label);}
    static bool getarraycontainkey(const std::string& key, const std::string& label, std::string steerID=read_steer::stdID ){
+      if ( read_steer::instances==NULL ) read_steer::instances = new std::map<string,read_steer*>();
       if ( read_steer::instances->count(steerID) == 0 ) return false;
       return read_steer::Steering(steerID)->arraycontainkey(key, label);}
    static void arraypushback_steer(const std::string& value, const std::string& label, std::string steerID=read_steer::stdID ){
+      if ( read_steer::instances==NULL ) read_steer::instances = new std::map<string,read_steer*>();
       if ( read_steer::instances->count(steerID) == 0 ) return;
       read_steer::Steering(steerID)->arraypushback(value, label);}
    // add values