Incorrect package name for multipart classes

compiler/psi/src/org/jetbrains/kotlin/psi/stubs/KotlinStubVersions.kt

@@ -29,7 +29,7 @@ object KotlinStubVersions {
     //      or changes are made to the core stub building code (org.jetbrains.kotlin.idea.decompiler.stubBuilder).
     // Increasing this version will lead to reindexing of all binary files that are potentially kotlin binaries (including all class files).
     // TODO: Before updating this, please see the kdoc at DeserializedMemberScope.computeDescriptors and KT-41859
-    private const val BINARY_STUB_VERSION = 71
+    private const val BINARY_STUB_VERSION = 72
 
     // Classfile stub version should be increased if changes are made to classfile stub building subsystem (org.jetbrains.kotlin.idea.decompiler.classFile)
     // Increasing this version will lead to reindexing of all classfiles.

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/stubBuilder/clsStubBuilding.kt

@@ -78,7 +78,7 @@ fun createMultifileClassStub(
     facadeFqName: FqName,
     components: ClsStubBuilderComponents
 ): KotlinFileStubImpl {
-    val packageFqName = facadeFqName.parent()
+    val packageFqName = header.packageName?.let { FqName(it) } ?: facadeFqName.parent()
     val partNames = header.data?.asList()?.map { it.substringAfterLast('/') }
     val fileStub = KotlinFileStubForIde.forMultifileClassStub(facadeFqName, partNames)
     setupFileStub(fileStub, packageFqName)