[FUNCTOR-8] [PATCH] Possible NPE in TransformedGenerator if getWrappedGenerator() is overridden to return null

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0

Environment

ubuntu 11.10, sun-jdk-6, eclipse galileo

• Assignee: Simone Tripodi
• Reporter: Bruno P. Kinoshita
• Created: 01/Nov/11 03:12
• Updated: 31/May/12 15:44
• Resolved: 31/May/12 15:44

Description

If we override getWrappedGenerator method in TransformedGenerator to return null, it may result in a NullPointerException if hashCode is called.

Attached the patch for it, and below a snippet of code to reproduce this issue.

TransformedGenerator<Integer, Integer> t = new TransformedGenerator<Integer, Integer>(
new IntegerRange(1, 10), new UnaryFunction<Integer, Integer>() {
public Integer evaluate(Integer obj)

{ return obj += 1; }

}) {
@Override
protected Generator<? extends Integer> getWrappedGenerator()

{ return null; }

};

TransformedGenerator<Integer, Integer> t2 = new TransformedGenerator<Integer, Integer>(
new IntegerRange(1, 10), new UnaryFunction<Integer, Integer>() {
public Integer evaluate(Integer obj)

{ return obj -= 1; }

});

System.out.println(t.equals(t2));

System.out.println(t.hashCode() == t2.hashCode()); // NPE

Cheers,
Bruno P. Kinoshita