Fix stub mismatch for top level declaration with JvmPackageName (KT-21831)

ClassId stores jvm name and it differs from kotlin name in that case.

 #KT-21831 Fixed

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/classFile/KotlinClsStubBuilder.kt

@@ -56,7 +56,8 @@ open class KotlinClsStubBuilder : ClsStubBuilder() {
         val kotlinClass = IDEKotlinBinaryClassCache.getKotlinBinaryClass(file, fileContent) ?: error("Can't find binary class for Kotlin file: $file")
         val header = kotlinClass.classHeader
         val classId = kotlinClass.classId
-        val packageFqName = classId.packageFqName
+        val packageFqName = header.packageName?.let { FqName(it) } ?: classId.packageFqName
+
         if (!header.metadataVersion.isCompatible()) {
             return createIncompatibleAbiVersionFileStub()
         }

idea/testData/decompiler/stubBuilder/TopJvmPackageName/TopJvmPackageName.kt

@@ -0,0 +1,9 @@
+@file:Suppress("UNCHECKED_CAST", "NOTHING_TO_INLINE", "INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+@file:JvmName("OtherKt")
+@file:kotlin.jvm.JvmPackageName("some.other.jvm")
+package some.other
+
+@SinceKotlin("1.2")
+fun foo() {}
+
+// JVM_FILE_NAME: OtherKt

idea/testData/decompiler/stubBuilder/TopJvmPackageName/TopJvmPackageName.txt

@@ -0,0 +1,21 @@
+PsiJetFileStubImpl[package=some.other]
+  PACKAGE_DIRECTIVE
+    DOT_QUALIFIED_EXPRESSION
+      REFERENCE_EXPRESSION[referencedName=some]
+      REFERENCE_EXPRESSION[referencedName=other]
+  IMPORT_LIST
+  FUN[fqName=some.other.foo, hasBlockBody=true, hasBody=true, hasTypeParameterListBeforeFunctionName=false, isExtension=false, isTopLevel=true, name=foo]
+    MODIFIER_LIST[public]
+      ANNOTATION_ENTRY[hasValueArguments=false, shortName=SinceKotlin]
+        CONSTRUCTOR_CALLEE
+          TYPE_REFERENCE
+            USER_TYPE
+              USER_TYPE
+                REFERENCE_EXPRESSION[referencedName=kotlin]
+              REFERENCE_EXPRESSION[referencedName=SinceKotlin]
+    VALUE_PARAMETER_LIST
+    TYPE_REFERENCE
+      USER_TYPE
+        USER_TYPE
+          REFERENCE_EXPRESSION[referencedName=kotlin]
+        REFERENCE_EXPRESSION[referencedName=Unit]

idea/tests/org/jetbrains/kotlin/idea/decompiler/stubBuilder/AbstractClsStubBuilderTest.kt

@@ -27,6 +27,7 @@ import com.intellij.util.indexing.FileContentImpl
 import org.jetbrains.kotlin.idea.decompiler.classFile.KotlinClsStubBuilder
 import org.jetbrains.kotlin.idea.stubs.AbstractStubBuilderTest
 import org.jetbrains.kotlin.psi.stubs.elements.KtFileStubBuilder
+import org.jetbrains.kotlin.test.InTextDirectivesUtils
 import org.jetbrains.kotlin.test.KotlinTestUtils
 import org.jetbrains.kotlin.test.MockLibraryUtil
 import org.jetbrains.kotlin.utils.addIfNotNull
@@ -36,8 +37,18 @@ import java.util.*
 
 abstract class AbstractClsStubBuilderTest : LightCodeInsightFixtureTestCase() {
     fun doTest(sourcePath: String) {
-        val classFile = getClassFileToDecompile(sourcePath)
+        val ktFile = File("$sourcePath/${lastSegment(sourcePath)}.kt")
+        val jvmFileName = if (ktFile.exists()) {
+            val ktFileText = ktFile.readText()
+            InTextDirectivesUtils.findStringWithPrefixes(ktFileText, "JVM_FILE_NAME:")
+        } else {
+            null
+        }
+
+        val classFile = getClassFileToDecompile(sourcePath, jvmFileName)
+
         val txtFilePath = File("$sourcePath/${lastSegment(sourcePath)}.txt")
+
         testClsStubsForFile(classFile, txtFilePath)
     }
 
@@ -53,11 +64,12 @@ abstract class AbstractClsStubBuilderTest : LightCodeInsightFixtureTestCase() {
         }
     }
 
-    private fun getClassFileToDecompile(sourcePath: String): VirtualFile {
+    private fun getClassFileToDecompile(sourcePath: String, classFileName: String?): VirtualFile {
         val outDir = KotlinTestUtils.tmpDir("libForStubTest-" + sourcePath)
         MockLibraryUtil.compileKotlin(sourcePath, outDir, extraOptions = listOf("-Xallow-kotlin-package"))
         val root = LocalFileSystem.getInstance().refreshAndFindFileByIoFile(outDir)!!
-        return root.findClassFileByName(lastSegment(sourcePath))
+
+        return root.findClassFileByName(classFileName ?: lastSegment(sourcePath))
     }
 
     private fun lastSegment(sourcePath: String): String {

idea/tests/org/jetbrains/kotlin/idea/decompiler/stubBuilder/ClsStubBuilderTestGenerated.java

@@ -181,6 +181,12 @@ public class ClsStubBuilderTestGenerated extends AbstractClsStubBuilderTest {
         doTest(fileName);
     }
 
+    @TestMetadata("TopJvmPackageName")
+    public void testTopJvmPackageName() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/decompiler/stubBuilder/TopJvmPackageName/");
+        doTest(fileName);
+    }
+
     @TestMetadata("TopLevelMembersAnnotatedKt")
     public void testTopLevelMembersAnnotatedKt() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/decompiler/stubBuilder/TopLevelMembersAnnotatedKt/");

idea/tests/org/jetbrains/kotlin/idea/decompiler/stubBuilder/ClsStubConsistencyTest.kt

@@ -32,7 +32,7 @@ import org.junit.Assert
 class ClsStubConsistencyTest : KotlinLightCodeInsightFixtureTestCase() {
     private fun doTest(id: ClassId) {
         val packageFile = VirtualFileFinder.SERVICE.getInstance(project).findVirtualFileWithHeader(id)
-                          ?: throw AssertionError("File not found for id: $id")
+                ?: throw AssertionError("File not found for id: $id")
         val decompiledText = buildDecompiledTextForClassFile(packageFile).text
         val fileWithDecompiledText = KtPsiFactory(project).createFile(decompiledText)
         val stubTreeFromDecompiledText = KtFileStubBuilder().buildStubTree(fileWithDecompiledText)