TypeDescriptor.forElementType() is broken for nested collections [SPR-7562] #12219
Description
Kevin Wright opened SPR-7562 and commented
The start of forElementType() is defined as:
if (getType().equals(elementType)) {
return this;
}
Unfortunately, this fails when the TypeDescriptor represents a List<List<...>>
When calling getElementType(), the call stack will be getElementType() -> getElementTypeDescriptor() -> forElementType()
at which point, the elementType field will still be null.
The equality check will therefore see that List<null> == List<null>, and so the TypeDescriptor will be returned as its own element descriptor.
This leads to a recursive definition, where the descriptor now represents a List<List<List<...<List<List<... etc.
Affects: 3.0.3
Issue Links:
- StackOverflowError when converting nested Lists [SPR-7289] #11948 StackOverflowError when converting nested Lists ("duplicates")