Re: [Simple-support] RegistryStrategy causes NPE when Converter is used

[Shevek <sh...@an...>]

On Sun, 2012-05-06 at 20:24 -0700, Shevek wrote:
> Test case is a bit tangled, but I can provide it if the explanation
> below isn't sufficient:
> 
> * Interface Value has a method getType() which returns the type of the
> value.
> 
> * However ArrayValue implements this to return the type of the element,
> not the array type. See TreeStrategy.read() lines circa 105, where
> 'actual', not 'expect' is passed to readArray().
> 
> * This causes RegistryStrategy's read() method to call lookup() with an
> element type, and return a Converter when it is actually holding the
> array node, not the element node.
> 
> * This causes the Converter to fail, since it gets given the InputNode
> for the array itself, not the InputNode for the array element, and so
> the attributes expected are not present.
> 
> Possible solutions:
> 
> 1) Pass 'actual', not 'expect' to ArrayValue. This makes ArrayValue
> satisfy the contract of Value, but may break things which rely on
> ArrayValue being a special case.
> 
> 2) During deserialization, at the point where RegistryStrategy calls
> lookup(), make it ignore Value.getType(), since that is invalid, and
> rely on the expected type if present. This may still have to use
> Value.getType() during serialization...

Changing read() to call lookup(type, null) fixes the bug. write() still
calls lookup(type, value)

S.