Bug 46967

On some platforms (z/OS for sure), the device file /dev/urandom can pass the "f.exists()" test, but throws an IOException of some kind when trying to open it.  The current code in ManagerBase.setRandomFile() doesn't handle this, which results in EVERY call to getRandom() to try again and log the error  "Failed to close randomIS".

The following changes to the method will add proper error handling to correct this (my changes marked "// kjw")

    public void setRandomFile( String s ) {
        // as a hack, you can use a static file - and genarate the same
        // session ids ( good for strange debugging )
        if (Globals.IS_SECURITY_ENABLED){
            randomIS = (DataInputStream)AccessController.doPrivileged(new PrivilegedSetRandomFile());          
        } else {
            try{
                devRandomSource=s;
                File f=new File( devRandomSource );
                if( ! f.exists() ) return;
                randomIS= new DataInputStream( new FileInputStream(f));
                randomIS.readLong();
                if( log.isDebugEnabled() )
                    log.debug( "Opening " + devRandomSource );
            } catch( IOException ex ) {
            	log.debug("Error reading " + devRandomSource, ex); //kjw
            	if (randomIS != null) {  // kjw: if opened
	                try {
	                    randomIS.close();
	                } catch (Exception e) {
	                    log.warn("Failed to close randomIS.");
	                }
            	}                       // kjw 
            	devRandomSource = null; // kjw: don't try again automatically
                randomIS=null;
            }
        }
    }