ModuleDescriptor now sees internals of its expected by #KT-15739 Fixed

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt

@@ -115,7 +115,7 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
     }
 
     override fun shouldSeeInternalsOf(targetModule: ModuleDescriptor): Boolean {
-        return this == targetModule || targetModule in dependencies!!.modulesWhoseInternalsAreVisible
+        return this == targetModule || targetModule in dependencies!!.modulesWhoseInternalsAreVisible || expectedByModule == targetModule
     }
 
     private val id: String

idea/testData/multiModuleHighlighting/multiplatform/internal/common/common.kt

@@ -0,0 +1,3 @@
+expect fun foo()
+
+internal fun bar() {}

idea/testData/multiModuleHighlighting/multiplatform/internal/jvm/foo.kt

@@ -0,0 +1,3 @@
+actual fun foo() {
+    bar() // should work
+}

idea/tests/org/jetbrains/kotlin/idea/caches/resolve/MultiPlatformHighlightingTest.kt

@@ -63,6 +63,10 @@ class MultiPlatformHighlightingTest : AbstractMultiModuleHighlightingTest() {
         doMultiPlatformTest(TargetPlatformKind.Jvm[JvmTarget.JVM_1_6])
     }
 
+    fun testInternal() {
+        doMultiPlatformTest(TargetPlatformKind.Jvm[JvmTarget.JVM_1_6])
+    }
+
     fun testSuppressHeaderWithoutImpl() {
         doMultiPlatformTest(TargetPlatformKind.Jvm[JvmTarget.JVM_1_6])
     }
@@ -77,12 +81,13 @@ class MultiPlatformHighlightingTest : AbstractMultiModuleHighlightingTest() {
 
     fun testUseCorrectBuiltInsForCommonModule() {
         doMultiPlatformTest(TargetPlatformKind.Jvm[JvmTarget.JVM_1_8], TargetPlatformKind.JavaScript,
-                            withStdlibCommon = true, jdk = TestJdkKind.FULL_JDK, configureModule = { module, platform ->
-            if (platform == TargetPlatformKind.JavaScript) {
-                module.addLibrary(ForTestCompileRuntime.stdlibJsForTests(), kind = JSLibraryKind)
-                module.addLibrary(ForTestCompileRuntime.stdlibCommonForTests())
-            }
-        })
+                            withStdlibCommon = true, jdk = TestJdkKind.FULL_JDK,
+                            configureModule = { module, platform ->
+                                if (platform == TargetPlatformKind.JavaScript) {
+                                    module.addLibrary(ForTestCompileRuntime.stdlibJsForTests(), kind = JSLibraryKind)
+                                    module.addLibrary(ForTestCompileRuntime.stdlibCommonForTests())
+                                }
+                            })
     }
 
     fun testHeaderClassImplTypealias() {