```
interface A {
fun <T> foo(): T
}
class B(val a: A) : A by A {
generated fun <T'> foo(): T' {
return a.foo() // <------
}
}
```
There was a problem that type of generated delegated call used
an unsubstituted type of the original delegated declaration, which led
to a situation when (see example) type of call `a.foo()` was not `T'`
but `T`, which led to incorrect IR and further exceptions on backend
^KT-64257 Fixed
^KT-64284 Obsolete
For type parameters of generic properties,
`DeclarationDescriptor#getContainingDeclaration` must return
the property descriptor instead of the accessor function descriptor.
^KT-57436 Fixed
The reason #1 for this feature is that we want to test IdSignatures
generated for declarations. Currently, there is no (easy) way to ensure
that a change in the signature building logic doesn't cause any breaking
changes wrt klibs.
Now, most IdSignatures include hashed mangled names in them, so even if
we catch a regression where the included hash changes, there would be no
way of knowing immediately what caused it, unless we'd also have mangled
names in the expectations.
The reason #2 is to test the manglers themselves. Currently, there are
no tests for them. They heavily duplicate each other, this is already
causing issues (see KT-57427) that would be very hard to catch without
these tests.
^KT-58238 Fixed
Dmitriy Novozhilov