Star projection information preserved in substitutions

#KT-6700 Fixed

core/descriptors/src/org/jetbrains/kotlin/types/CapturedTypeApproximation.kt

@@ -72,6 +72,7 @@ private fun TypeProjection.toTypeArgument(typeParameter: TypeParameterDescriptor
 
 public fun approximateCapturedTypesIfNecessary(typeProjection: TypeProjection?): TypeProjection? {
     if (typeProjection == null) return null
+    if (typeProjection.isStarProjection()) return typeProjection
 
     val type = typeProjection.getType()
     if (!TypeUtils.containsSpecialType(type, { it.isCaptured() })) {

core/descriptors/src/org/jetbrains/kotlin/types/TypeSubstitutor.java

@@ -165,6 +165,8 @@ public class TypeSubstitutor {
     private TypeProjection unsafeSubstitute(@NotNull TypeProjection originalProjection, int recursionDepth) throws SubstitutionException {
         assertRecursionDepth(recursionDepth, originalProjection, substitution);
 
+        if (originalProjection.isStarProjection()) return originalProjection;
+
         // The type is within the substitution range, i.e. T or T?
         JetType type = originalProjection.getType();
         Variance originalProjectionKind = originalProjection.getProjectionKind();
@@ -278,7 +280,7 @@ public class TypeSubstitutor {
             switch (conflictType(typeParameter.getVariance(), substitutedTypeArgument.getProjectionKind())) {
                 case NO_CONFLICT:
                     // if the corresponding type parameter is already co/contra-variant, there's not need for an explicit projection
-                    if (typeParameter.getVariance() != Variance.INVARIANT) {
+                    if (typeParameter.getVariance() != Variance.INVARIANT && !substitutedTypeArgument.isStarProjection()) {
                         substitutedTypeArgument = new TypeProjectionImpl(Variance.INVARIANT, substitutedTypeArgument.getType());
                     }
                     break;

core/descriptors/src/org/jetbrains/kotlin/types/TypeUtils.kt

@@ -28,6 +28,8 @@ import org.jetbrains.kotlin.utils.toReadOnlyList
 import org.jetbrains.kotlin.types.checker.JetTypeChecker
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.types.isDynamic
+import org.jetbrains.kotlin.types.TypeProjection
+import org.jetbrains.kotlin.types.TypeProjectionImpl
 
 fun JetType.getContainedTypeParameters(): Collection<TypeParameterDescriptor> {
     val declarationDescriptor = getConstructor().getDeclarationDescriptor()
@@ -66,4 +68,8 @@ public fun JetType.isSubtypeOf(superType: JetType): Boolean = JetTypeChecker.DEF
 
 public fun JetType.cannotBeReified(): Boolean = KotlinBuiltIns.isNothingOrNullableNothing(this) || this.isDynamic()
 
-
+fun TypeProjection.substitute(doSubstitute: (JetType) -> JetType): TypeProjection {
+    return if (isStarProjection())
+        this
+    else TypeProjectionImpl(getProjectionKind(), doSubstitute(getType()))
+}