Fix MPP publishing with metadata on Gradle 5.2 (KT-29758)

In publishing, use attribute containers of detached configuration
instead of HierarchyAttributeContainer, which is rejected by Gradle for
not being an AttributeContainerInternal.

Using attributes of a detached configuration is a small and
conservative fix; we may need to either not filter the attributes,
which will lead to [ProjectLocalConfigurations.ATTRIBUTE] being
published in the Gradle module metadata, which will potentially
complicate our attributes schema migration, or create proper,
non-detached configurations for publishing that are separated from the
configurations used for project-to-project dependencies.

Issue #KT-29758 Fixed

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/HierarchyAttributeContainer.kt

@@ -20,6 +20,13 @@ import org.gradle.api.attributes.AttributeContainer
 import java.util.*
 
 // TODO better implementation: attribute invariants (no attrs with same name and different types allowed), thread safety?
+/** An attribute container that delegates attributes lookup to the [parent] when the key matches [filterParentAttributes] and is missing
+ * in this container.
+ *
+ * This container should never be passed to any Gradle API, as Gradle assumes all [AttributeContainer] instances to
+ * implement AttributeContainerInternal.
+ * TODO expose Kotlin-specific API to the users, convert the user attributes to Gradle attributes internally
+ */
 class HierarchyAttributeContainer(
     val parent: AttributeContainer?,
     val filterParentAttributes: (Attribute<*>) -> Boolean = { true }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinSoftwareComponent.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.gradle.plugin.mpp
 
 import org.gradle.api.Project
 import org.gradle.api.artifacts.*
+import org.gradle.api.attributes.Attribute
 import org.gradle.api.attributes.AttributeContainer
 import org.gradle.api.attributes.Usage
 import org.gradle.api.capabilities.Capability
@@ -85,8 +86,28 @@ class DefaultKotlinUsageContext(
         // TODO Gradle Java plugin does that in a different way; check whether we can improve this
         configuration.artifacts
 
-    override fun getAttributes(): AttributeContainer =
-        HierarchyAttributeContainer(configuration.outgoing.attributes) { it != ProjectLocalConfigurations.ATTRIBUTE }
+    override fun getAttributes(): AttributeContainer {
+        val configurationAttributes = configuration.attributes
+
+        /** TODO Using attributes of a detached configuration is a small and 'conservative' fix for KT-29758, [HierarchyAttributeContainer]
+         * being rejected by Gradle 5.2+; we may need to either not filter the attributes, which will lead to
+         * [ProjectLocalConfigurations.ATTRIBUTE] being published in the Gradle module metadata, which will potentially complicate our
+         * attributes schema migration, or create proper, non-detached configurations for publishing that are separated from the
+         * configurations used for project-to-project dependencies
+         */
+        val result = project.configurations.detachedConfiguration().attributes
+
+        // Capture type parameter T:
+        fun <T> copyAttribute(attribute: Attribute<T>, from: AttributeContainer, to: AttributeContainer) {
+            to.attribute<T>(attribute, from.getAttribute(attribute)!!)
+        }
+
+        configurationAttributes.keySet()
+            .filter { it != ProjectLocalConfigurations.ATTRIBUTE }
+            .forEach { copyAttribute(it, configurationAttributes, result) }
+
+        return result
+    }
 
     override fun getCapabilities(): Set<Capability> = emptySet()