Incompatible supertypes check also don't provoke runtime problems
in most situations, because this check is also bound to type argument
conflict. Related to KT-54411
The situations with conflicting type arguments normally don't provoke
any runtime problems. Also, conflicts like A<T> VS A<SomeType> aren't
valid at all. Here we decided to remove them to avoid strange
and non-actionable warnings in user code.
#KT-54411 Fixed
Otherwise, exception from org.jetbrains.kotlin.resolve.calls.inference.components.ConstraintInjector.TypeCheckerStateForConstraintInjector.fixedTypeVariable
might happen during forks resolution
The test data is extracted from intelliJ FP test
^KT-43296 Fixed
Otherwise, OVERLOAD_RESOLUTION_AMBIGUITY is reported for the calls to
the functions annotated as @OverloadResolutionByLambdaReturnType
^KT-43296 In Progress
The idea is that we should not fix (i.e. choose any of the fork branches)
on the stage of candidate processing before completion, but it's enough
just to check that current state can be converged to success.
And when completion starts, and we add expected type to the system,
we've got more information to choose the correct fork branch.
NB: The old `processForkConstraints` is being called just
at the beginning of the completion phase.
^KT-43296 In Progress
Report an error that inference will change and type has to be provided
manually in other language versions, since the current behavior is an
unsoundness that can cause runtime NPEs while the new behavior may
silently change overload resolution.
^KT-30054 Fixed
It's reported on receivers in extension function calls with stub type,
as such calls can shadow members of finalized stub types causing
change of resolve when corresponding type argument specified explicitly
It works by checking extension receiver during call resolution parts run
That way we can easily detect if we found an extension applicable to
stub receiver and report call diagnostic for it
KT-53739
Let's call builder lambdas (BL) a lambda that has non-fixed input type
projection at the moment of lambda arguments analysis, such lambdas
is a subject to be analyzed with builder inference
Due to bug in constraint system joining algorithm, currently system
of two or more such lambdas may lead to unsound type inference
Diagnostic added here should be reported in case when there are two
BL that shares a common constraint system, while not annotated with
@BuilderInference, as a protection against aforementioned bug
It's reported by ConstraintSystemCompleter when such situation has
occurred during builder inference phase, it is the same place that
decides wherever lambdas is subject to builder inference or not
KT-53740
In K1, upper bound violated causes candidate to have lower applicability
due to constraint errors, in K2 however constraint errors has to be
reported explicitly
The original case provoked forking a constraint system which isn't supported in K1 (K2 only). If the captured type is recursive, then type parameter's upper bounds may break subtyping due to substitution the current captured type again, into a recursive type parameter.
Note that we already have special logic for recursive captured types. See `isTypeVariableAgainstStarProjectionForSelfType`.
^KT-52782 Fixed
Dmitriy Novozhilov