[Gradle] Fix warnings in DefaultKotlinJavaToolchain

^KT-56904 In Progress

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/tasks/DefaultKotlinJavaToolchain.kt

@@ -16,6 +16,7 @@ import org.gradle.api.model.ObjectFactory
 import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.api.provider.Property
 import org.gradle.api.provider.Provider
+import org.gradle.api.provider.ProviderFactory
 import org.gradle.api.tasks.Internal
 import org.gradle.internal.jvm.Jvm
 import org.gradle.jvm.toolchain.*
@@ -32,6 +33,7 @@ import javax.inject.Inject
 internal abstract class DefaultKotlinJavaToolchain @Inject constructor(
     private val objects: ObjectFactory,
     projectLayout: ProjectLayout,
+    providerFactory: ProviderFactory,
     jvmCompilerOptions: () -> KotlinJvmCompilerOptions?
 ) : KotlinJavaToolchain {
 
@@ -86,13 +88,14 @@ internal abstract class DefaultKotlinJavaToolchain @Inject constructor(
         .chainedFinalizeValueOnRead()
 
     private fun getToolsJarFromJvm(
+        providerFactory: ProviderFactory,
         jvmProvider: Provider<Jvm>,
         javaVersionProvider: Provider<JavaVersion>
     ): Provider<File?> {
         return objects
             .propertyWithConvention(
                 javaVersionProvider.flatMap { javaVersion ->
-                    jvmProvider.map { jvm ->
+                    jvmProvider.mapOrNull(providerFactory) { jvm ->
                         jvm.toolsJar.also {
                             if (it == null && javaVersion < JavaVersion.VERSION_1_9) {
                                 throw GradleException(
@@ -107,10 +110,11 @@ internal abstract class DefaultKotlinJavaToolchain @Inject constructor(
     }
 
     @get:Internal
-    internal val jdkToolsJar: Provider<File?> = getToolsJarFromJvm(buildJvm, javaVersion)
+    internal val jdkToolsJar: Provider<File?> = getToolsJarFromJvm(providerFactory, buildJvm, javaVersion)
 
     @get:Internal
     internal val currentJvmJdkToolsJar: Provider<File?> = getToolsJarFromJvm(
+        providerFactory,
         gradleJvm,
         gradleJvm.map {
             // Current JVM should always have java version

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/utils/providerApiUtils.kt

@@ -16,6 +16,13 @@ import org.gradle.api.provider.*
 import java.io.File
 import kotlin.reflect.KProperty
 
+// Workaround for https://github.com/gradle/gradle/issues/12388
+// which should be fixed via https://github.com/gradle/gradle/issues/24767
+internal fun <IN : Any, OUT> Provider<IN>.mapOrNull(
+    providerFactory: ProviderFactory,
+    block: (IN) -> OUT?
+): Provider<OUT> = flatMap { providerFactory.provider { (block(it)) } }
+
 internal operator fun <T> Provider<T>.getValue(thisRef: Any?, property: KProperty<*>) = get()
 
 internal operator fun <T> Property<T>.setValue(thisRef: Any?, property: KProperty<*>, value: T) {