CopyKotlinDeclarationsHandler: fix for package with backticks

#KT-38543 Fixed

idea/src/org/jetbrains/kotlin/idea/refactoring/copy/CopyKotlinDeclarationsHandler.kt

@@ -24,11 +24,12 @@ import com.intellij.usageView.UsageInfo
 import com.intellij.util.IncorrectOperationException
 import com.intellij.util.containers.MultiMap
 import org.jetbrains.annotations.TestOnly
+import org.jetbrains.kotlin.idea.KotlinBundle
 import org.jetbrains.kotlin.idea.codeInsight.shorten.performDelayedRefactoringRequests
 import org.jetbrains.kotlin.idea.core.getFqNameWithImplicitPrefix
 import org.jetbrains.kotlin.idea.core.packageMatchesDirectoryOrImplicit
+import org.jetbrains.kotlin.idea.core.quoteIfNeeded
 import org.jetbrains.kotlin.idea.core.util.toPsiDirectory
-import org.jetbrains.kotlin.idea.KotlinBundle
 import org.jetbrains.kotlin.idea.refactoring.checkConflictsInteractively
 import org.jetbrains.kotlin.idea.refactoring.createKotlinFile
 import org.jetbrains.kotlin.idea.refactoring.move.*
@@ -126,7 +127,8 @@ class CopyKotlinDeclarationsHandler : CopyHandlerDelegateBase() {
         targetFileName: String,
         targetDirectory: PsiDirectory
     ): ExistingFilePolicy {
-        val message = KotlinBundle.message("text.file.0.already.exists.in.1",
+        val message = KotlinBundle.message(
+            "text.file.0.already.exists.in.1",
             targetFileName,
             targetDirectory.virtualFile.path
         )
@@ -291,7 +293,7 @@ class CopyKotlinDeclarationsHandler : CopyHandlerDelegateBase() {
                 if (targetKtFile !== null) {
                     runWriteAction {
                         if (!targetKtFile.packageMatchesDirectoryOrImplicit()) {
-                            targetKtFile.containingDirectory?.getFqNameWithImplicitPrefix()?.let { targetDirectoryFqName ->
+                            targetKtFile.containingDirectory?.getFqNameWithImplicitPrefix()?.quoteIfNeeded()?.let { targetDirectoryFqName ->
                                 targetKtFile.packageFqName = targetDirectoryFqName
                             }
                         }
@@ -419,8 +421,9 @@ class CopyKotlinDeclarationsHandler : CopyHandlerDelegateBase() {
             val targetDirectoryFqName = targetDirectory.getFqNameWithImplicitPrefix()
             val copiedFile = targetDirectory.copyFileFrom(targetFileName, fileToCopy)
             if (copiedFile is KtFile && fileToCopy.packageMatchesDirectoryOrImplicit()) {
-                targetDirectoryFqName?.let { copiedFile.packageFqName = it }
+                targetDirectoryFqName?.quoteIfNeeded()?.let { copiedFile.packageFqName = it }
             }
+
             performDelayedRefactoringRequests(sourceData.project)
             copiedFile
         }

idea/testData/refactoring/copy/copyFileToRoot/after/Foo.kt

@@ -0,0 +1,3 @@
+package root.`20-20`
+
+class Foo

idea/testData/refactoring/copy/copyFileToRoot/after/Root.kt

@@ -0,0 +1,3 @@
+package root.`20-20`
+
+class Root

idea/testData/refactoring/copy/copyFileToRoot/after/foo/Foo.kt

@@ -0,0 +1,3 @@
+package foo
+
+class Foo

idea/testData/refactoring/copy/copyFileToRoot/before/Root.kt

@@ -0,0 +1,3 @@
+package root.`20-20`
+
+class Root

idea/testData/refactoring/copy/copyFileToRoot/before/foo/Foo.kt

@@ -0,0 +1,3 @@
+package foo
+
+class Foo

idea/testData/refactoring/copy/copyFileToRoot/copyFileToRoot.test

@@ -0,0 +1,4 @@
+{
+  "mainFile": "foo/Foo.kt",
+  "targetPackage": ""
+}

idea/tests/org/jetbrains/kotlin/idea/refactoring/copy/CopyTestGenerated.java

@@ -83,6 +83,11 @@ public class CopyTestGenerated extends AbstractCopyTest {
         runTest("idea/testData/refactoring/copy/copyFIleToDefaultPackage/copyFIleToDefaultPackage.test");
     }
 
+    @TestMetadata("copyFileToRoot/copyFileToRoot.test")
+    public void testCopyFileToRoot_CopyFileToRoot() throws Exception {
+        runTest("idea/testData/refactoring/copy/copyFileToRoot/copyFileToRoot.test");
+    }
+
     @TestMetadata("copyFIleWithPackageAndDirUnmatched/copyFIleWithPackageAndDirUnmatched.test")
     public void testCopyFIleWithPackageAndDirUnmatched_CopyFIleWithPackageAndDirUnmatched() throws Exception {
         runTest("idea/testData/refactoring/copy/copyFIleWithPackageAndDirUnmatched/copyFIleWithPackageAndDirUnmatched.test");