Parent class type detector doesn't check instances (C#/Java)

[LogicAndTrick]

This one's pretty obscure, but there's definitely a bug here.

The compiler seems to have some logic to check if a type is used in multiple locations to determine whether the parent is a known type or whether it should just a a generic KaitaiStruct type. (ClassCompiler.scala@markupParentTypes)

This check doesn't check the usages of the type inside instances. If only one type uses it in the seq section, but other types use it in the instances section, the resulting output won't compile.

I tried to fix this one by adding to markupParentTypes, but I couldn't work it out (I'm not familiar enough with the type system yet).

---

KSY to replicate the bug:

meta:
  id: multiple_use
  endian: le
seq:
  - id: t1
    type: type_1
  - id: t2
    type: type_2
types:
  multi:
    seq:
      - id: value
        type: s4
  type_1:
    seq:
      - id: first_use
        type: multi  # parent type = type_1
  type_2:
    seq: []
    instances:
      second_use:
        pos: 0
        type: multi  # parent type = type_2

Compiled result (similar problems in both C# and Java):

// Error CS1503 - Argument 2: cannot convert from 'MultipleUse.Type2' to 'MultipleUse.Type1'
class MultipleUse : KaitaiStruct
{
    ...

    // Note here that `parent` is `Type1`. It should be `KaitaiStruct`.
    class Multi : KaitaiStruct
    {
        public Multi(KaitaiStream io, Type1 parent = null, MultipleUse root = null) : base(io) { ... }
    }

    class Type1 : KaitaiStruct
    {
        ...

        private void _parse()
        {
            _firstUse = new Multi(m_io, this, m_root);
        }
    }

    class Type2 : KaitaiStruct
    {
        public Multi SecondUse
        {
            get
            {
                ...
                _secondUse = new Multi(m_io, this, m_root); // <--- compile error here
                ...
            }
        }
    }
}

Temporary work around:

# Add this to `seq`:
  - id: unused
    type: multi
    if: false

[GreyCat]

Fantastic job, as always, @LogicAndTrick, thanks :)
I'll try to fix that one.

[GreyCat]

By the way, you're welcome to check in these test .ksys directly into tests :)

[GreyCat]

Seems to be fixed. I've added test spec for Java, probably we'll have to add them now for the rest of the languages...

[GreyCat]

Tests for everything beside C++ (not working now, need more namespacing tweaks) and PHP (under development anyway) are ready and passing - see http://kaitai.io/ci/ - I guess I'm closing this one as solved.