Description

The default parameter "alphabet" is set to 0123456789, but with this value, when the generated number value contain at least one 0, the image can't be displayed.

It is because in jpgraph_antispam.php , in the Stroke() function, there is a part of code which return false when the generated number contain one 0(number) or on O (letter).

for($i=0; $i < $n; ++$i ) {
    if( $this->iData[$i]==='0' || strtolower($this->iData[$i])==='o') {
	return false;
    }
}