Create from Usage: Fix exception in "Create class" quickfix applied to unresolved references in type arguments. Create class body when necessary

#KT-12777 Fixed
(cherry picked from commit dc90ec9)

ChangeLog.md

@@ -208,6 +208,7 @@
 - [`KT-11975`](https://youtrack.jetbrains.com/issue/KT-11975) "Invert if-condition" intention does not simplify `is` expression
 - [`KT-12437`](https://youtrack.jetbrains.com/issue/KT-12437) "Replace explicit parameter" intention is suggested for parameter of inner lambda in presence of `it` from outer lambda
 - [`KT-12376`](https://youtrack.jetbrains.com/issue/KT-12376) Don't show "Package directive doesn't match file location" in injected code
+- [`KT-12777`](https://youtrack.jetbrains.com/issue/KT-12777) Fix exception in "Create class" quickfix applied to unresolved references in type arguments
 
 #### Language injection
 

idea/src/org/jetbrains/kotlin/idea/quickfix/createFromUsage/callableBuilder/CallableBuilder.kt

@@ -531,8 +531,9 @@ class CallableBuilder(val config: CallableBuilderConfiguration) {
                     return Math.max(lineBreaksNeeded - lineBreaksPresent, 0)
                 }
 
+                val actualContainer = (containingElement as? KtClassOrObject)?.getOrCreateBody() ?: containingElement
+
                 fun addNextToOriginalElementContainer(addBefore: Boolean): KtNamedDeclaration {
-                    val actualContainer = (containingElement as? KtClassOrObject)?.getBody() ?: containingElement
                     val sibling = config.originalElement.parentsWithSelf.first { it.parent == actualContainer }
                     return if (addBefore) {
                         actualContainer.addBefore(declaration, sibling)
@@ -543,7 +544,7 @@ class CallableBuilder(val config: CallableBuilderConfiguration) {
                 }
 
                 val declarationInPlace = when {
-                    containingElement.isAncestor(config.originalElement, true) -> {
+                    actualContainer.isAncestor(config.originalElement, true) -> {
                         val insertToBlock = containingElement is KtBlockExpression
                         if (insertToBlock) {
                             val parent = containingElement.parent

idea/testData/quickfix/createFromUsage/createClass/typeReference/nestedClassByTypeArgumentRefNoBody.kt

@@ -0,0 +1,4 @@
+// "Create class 'X'" "true"
+open class A<T>
+
+class B : A<B.<caret>X>()

idea/testData/quickfix/createFromUsage/createClass/typeReference/nestedClassByTypeArgumentRefNoBody.kt.after

@@ -0,0 +1,8 @@
+// "Create class 'X'" "true"
+open class A<T>
+
+class B : A<B.X>() {
+    class X {
+
+    }
+}

idea/testData/quickfix/createFromUsage/createClass/typeReference/nestedClassByTypeArgumentRefWithBody.kt

@@ -0,0 +1,6 @@
+// "Create class 'X'" "true"
+open class A<T>
+
+class B : A<B.<caret>X>() {
+
+}

idea/testData/quickfix/createFromUsage/createClass/typeReference/nestedClassByTypeArgumentRefWithBody.kt.after

@@ -0,0 +1,9 @@
+// "Create class 'X'" "true"
+open class A<T>
+
+class B : A<B.X>() {
+    class X {
+
+    }
+
+}

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java

@@ -1788,6 +1788,18 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("nestedClassByTypeArgumentRefNoBody.kt")
+                public void testNestedClassByTypeArgumentRefNoBody() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createClass/typeReference/nestedClassByTypeArgumentRefNoBody.kt");
+                    doTest(fileName);
+                }
+
+                @TestMetadata("nestedClassByTypeArgumentRefWithBody.kt")
+                public void testNestedClassByTypeArgumentRefWithBody() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createClass/typeReference/nestedClassByTypeArgumentRefWithBody.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("objectNotQualifierNoTypeArgs.kt")
                 public void testObjectNotQualifierNoTypeArgs() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createClass/typeReference/objectNotQualifierNoTypeArgs.kt");