Use correct module name when calling internal members from other module

This is needed to avoid using the same module name for test root as for
the main source root in the Gradle plugin, which is needed to fix
KT-18955

compiler/backend/src/org/jetbrains/kotlin/codegen/state/KotlinTypeMapper.java

@@ -1098,12 +1098,18 @@ public class KotlinTypeMapper {
         if (!(descriptor instanceof ConstructorDescriptor) &&
             descriptor.getVisibility() == Visibilities.INTERNAL &&
             !DescriptorUtilsKt.isPublishedApi(descriptor)) {
-            return InternalNameMapper.mangleInternalName(name, moduleName);
+            return InternalNameMapper.mangleInternalName(name, getModuleName(descriptor));
         }
 
         return name;
     }
 
+    @NotNull
+    private String getModuleName(@NotNull CallableMemberDescriptor descriptor) {
+        String deserialized = ModuleNameKt.getJvmModuleNameForDeserializedDescriptor(descriptor);
+        return deserialized != null ? deserialized : moduleName;
+    }
+
     @Nullable
     private static String getPartSimpleNameForMangling(@NotNull CallableMemberDescriptor descriptor) {
         KtFile containingFile = DescriptorToSourceUtils.getContainingFile(descriptor);

compiler/testData/compileKotlinAgainstKotlin/internalWithOtherModuleName.kt

@@ -0,0 +1,14 @@
+// IGNORE_BACKEND: NATIVE
+// FILE: A.kt
+
+package a
+
+class Box(val value: String) {
+    internal fun result(): String = value
+}
+
+// FILE: B.kt
+
+fun box(): String {
+    return a.Box("OK").result()
+}

compiler/tests-common/tests/org/jetbrains/kotlin/codegen/AbstractCompileKotlinAgainstKotlinTest.java

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.cli.common.modules.ModuleBuilder;
 import org.jetbrains.kotlin.cli.jvm.compiler.EnvironmentConfigFiles;
 import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment;
 import org.jetbrains.kotlin.codegen.forTestCompile.ForTestCompileRuntime;
+import org.jetbrains.kotlin.config.CommonConfigurationKeys;
 import org.jetbrains.kotlin.config.CompilerConfiguration;
 import org.jetbrains.kotlin.load.kotlin.ModuleVisibilityManager;
 import org.jetbrains.kotlin.load.kotlin.PackagePartClassUtils;
@@ -25,7 +26,6 @@ import org.jetbrains.kotlin.test.KotlinTestUtils;
 import org.jetbrains.kotlin.utils.ExceptionUtilsKt;
 
 import java.io.File;
-import java.io.IOException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.Arrays;
@@ -90,12 +90,14 @@ public abstract class AbstractCompileKotlinAgainstKotlinTest extends CodegenTest
     }
 
     @NotNull
-    private ClassFileFactory compileA(@NotNull TestFile testFile, List<TestFile> files) throws IOException {
+    private ClassFileFactory compileA(@NotNull TestFile testFile, List<TestFile> files) {
         Disposable compileDisposable = createDisposable("compileA");
-        CompilerConfiguration configuration =
-                createConfiguration(ConfigurationKind.ALL, getJdkKind(files),
-                                    Collections.singletonList(KotlinTestUtils.getAnnotationsJar()),
-                                    Collections.emptyList(), Collections.singletonList(testFile));
+        CompilerConfiguration configuration = createConfiguration(
+                ConfigurationKind.ALL, getJdkKind(files), Collections.singletonList(KotlinTestUtils.getAnnotationsJar()),
+                Collections.emptyList(), Collections.singletonList(testFile)
+        );
+
+        configuration.put(CommonConfigurationKeys.MODULE_NAME, "a");
 
         KotlinCoreEnvironment environment = KotlinCoreEnvironment.createForTests(
                 compileDisposable, configuration, EnvironmentConfigFiles.JVM_CONFIG_FILES);
@@ -110,16 +112,18 @@ public abstract class AbstractCompileKotlinAgainstKotlinTest extends CodegenTest
     }
 
     @NotNull
-    private ClassFileFactory compileB(@NotNull TestFile testFile, List<TestFile> files) throws IOException {
+    private ClassFileFactory compileB(@NotNull TestFile testFile, List<TestFile> files) {
         String commonHeader = StringsKt.substringBefore(files.get(0).content, "FILE:", "");
-        CompilerConfiguration configurationWithADirInClasspath =
-                createConfiguration(ConfigurationKind.ALL, getJdkKind(files),
-                                    Lists.newArrayList(KotlinTestUtils.getAnnotationsJar(), aDir),
-                                    Collections.emptyList(), Lists.newArrayList(testFile, new TestFile("header", commonHeader)));
+        CompilerConfiguration configuration = createConfiguration(
+                ConfigurationKind.ALL, getJdkKind(files), Lists.newArrayList(KotlinTestUtils.getAnnotationsJar(), aDir),
+                Collections.emptyList(), Lists.newArrayList(testFile, new TestFile("header", commonHeader))
+        );
+
+        configuration.put(CommonConfigurationKeys.MODULE_NAME, "b");
 
         Disposable compileDisposable = createDisposable("compileB");
         KotlinCoreEnvironment environment = KotlinCoreEnvironment.createForTests(
-                compileDisposable, configurationWithADirInClasspath, EnvironmentConfigFiles.JVM_CONFIG_FILES
+                compileDisposable, configuration, EnvironmentConfigFiles.JVM_CONFIG_FILES
         );
 
         return compileKotlin(Collections.singletonList(testFile), bDir, environment, compileDisposable);

compiler/tests/org/jetbrains/kotlin/codegen/CompileKotlinAgainstKotlinTestGenerated.java

@@ -138,6 +138,11 @@ public class CompileKotlinAgainstKotlinTestGenerated extends AbstractCompileKotl
         runTest("compiler/testData/compileKotlinAgainstKotlin/internalSetterOverridden.kt");
     }
 
+    @TestMetadata("internalWithOtherModuleName.kt")
+    public void testInternalWithOtherModuleName() throws Exception {
+        runTest("compiler/testData/compileKotlinAgainstKotlin/internalWithOtherModuleName.kt");
+    }
+
     @TestMetadata("jvmField.kt")
     public void testJvmField() throws Exception {
         runTest("compiler/testData/compileKotlinAgainstKotlin/jvmField.kt");