BuildscriptKotlinDefaults: ensure configureDefaultsIdeaKotlinJava is applied to target project, workarounds for some edge cases with setting jvm versions

gradle/BuildscriptKotlinDefaults.gradle

@@ -10,6 +10,7 @@ buildscript {
 
     repositories {
         mavenCentral()
+        // gradlePluginPortal()
     }
 
     dependencies {
@@ -59,21 +60,27 @@ ext.useCompactKotlinSourceSets = { org.gradle.api.Project target ->
 
 // configure defaults for java and jdk versions based on provided variables and enable intellij idea integration
 ext.configureDefaultsIdeaKotlinJava = { org.gradle.api.Project target ->
-    idea {
+    target.idea {
         module {
             downloadJavadoc = true
             downloadSources = true
         }
     }
-    kotlin {
+    target.kotlin {
         compilerOptions {
-            jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.valueOf("JVM_${javaVersion}"))
+            // jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.valueOf("JVM_${javaVersion}"))
+            // workaround for mismatch classloader issues sometimes happening
+            var newValue = jvmTarget.get().class.getEnumConstants().find { it.target == "${javaVersion}" }
+            jvmTarget.set(newValue)
         }
         jvmToolchain {
+            var newVersion = JavaLanguageVersion.of(jdkVersion)
+            if (newVersion != languageVersion.getOrNull()) {
                 languageVersion.set(JavaLanguageVersion.of(jdkVersion))
             }
         }
-    java {
+    }
+    target.java {
         sourceCompatibility = JavaVersion.toVersion(javaVersion)
         targetCompatibility = JavaVersion.toVersion(javaVersion)
         withJavadocJar()