DMN npe when xml defines empty default expression for DT

If you execute the DMN table in attach in the last version you will have a NullPointerException in case your input value is not matching any output.
We are moving from version 23 to 33 and one of our tests are catching this issue

The ProcessedExpression Class seems can be responsible of causing this NullPointerException.

this.ast = (BaseNode)tree.accept(new ASTBuilderVisitor(ctx.getInputVariableTypes(), ctx.getFEELFeelTypeRegistry()))

If you try with

"inputString", "hi"
"inputInteger", 12
"inputBoolean", false
"inputDate", "2019-09-26T00:00:00.000+0000"

you can replicate the error

I guess the expected behavior should be a null output as before