Parcelize: Handle class hierarchies of Parcelers (KT-46567)

plugins/parcelize/parcelize-compiler/testData/box/kt46567.kt

@@ -0,0 +1,64 @@
+// WITH_RUNTIME
+
+@file:JvmName("TestKt")
+package test
+
+import kotlinx.parcelize.*
+import android.os.Parcel
+import android.os.Parcelable
+import java.util.Arrays
+
+/**
+ * Generic pair parceler
+ * Create concrete object to use (see below)
+ */
+open class PairParceler<F: Any, S: Any>(private val firstParceler: Parceler<F>, private val secondParceler: Parceler<S>): Parceler<Pair<F, S>> {
+    /**
+     * Reads the [T] instance state from the [parcel], constructs the new [T] instance and returns it.
+     */
+    override fun create(parcel: Parcel): Pair<F, S> =
+        firstParceler.create(parcel) to secondParceler.create(parcel)
+
+    /**
+     * Writes the [T] instance state to the [parcel].
+     */
+    override fun Pair<F, S>.write(parcel: Parcel, flags: Int) {
+        with(firstParceler) { this@write.first.write(parcel, 0) }
+        with(secondParceler) { this@write.second.write(parcel, 0) }
+    }
+}
+
+object IntParceler: Parceler<Int> {
+    /**
+     * Reads the [T] instance state from the [parcel], constructs the new [T] instance and returns it.
+     */
+    override fun create(parcel: Parcel): Int = parcel.readInt()
+
+    /**
+     * Writes the [T] instance state to the [parcel].
+     */
+    override fun Int.write(parcel: Parcel, flags: Int) {
+        parcel.writeInt(this)
+    }
+}
+
+/**
+ * [Int] to [Int] pair parceler
+ */
+object IntToIntParceler: PairParceler<Int, Int>(IntParceler, IntParceler)
+
+@Parcelize
+@TypeParceler<Pair<Int, Int>, IntToIntParceler>
+class A(val pair: Pair<Int, Int>): Parcelable
+
+fun box() = parcelTest { parcel ->
+    val a1 = A(1 to 2)
+    a1.writeToParcel(parcel, 0)
+
+    val bytes = parcel.marshall()
+    parcel.unmarshall(bytes, 0, bytes.size)
+    parcel.setDataPosition(0)
+
+    val a2 = readFromParcel<A>(parcel)
+    assert(a1.pair == a2.pair)
+}