Fix NPE in KtSourceElement.elementType #KT-44152 Fixed

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -46857,6 +46857,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/toArray/kt3177-toTypedArray.kt");
         }
 
+        @Test
+        @TestMetadata("kt44152.kt")
+        public void testKt44152() throws Exception {
+            runTest("compiler/testData/codegen/box/toArray/kt44152.kt");
+        }
+
         @Test
         @TestMetadata("returnToTypedArray.kt")
         public void testReturnToTypedArray() throws Exception {

compiler/frontend.common/src/org/jetbrains/kotlin/KtSourceElement.kt

@@ -221,7 +221,7 @@ class KtOffsetsOnlySourceElement(
 
 // TODO: consider renaming to something like AstBasedSourceElement
 sealed class KtSourceElement : AbstractKtSourceElement() {
-    abstract val elementType: IElementType
+    abstract val elementType: IElementType?
     abstract val kind: KtSourceElementKind
     abstract val lighterASTNode: LighterASTNode
     abstract val treeStructure: FlyweightCapableTreeStructure<LighterASTNode>
@@ -233,11 +233,11 @@ sealed class KtSourceElement : AbstractKtSourceElement() {
     abstract override fun equals(other: Any?): Boolean
 }
 
-// NB: in certain situations, psi.node could be null
+// NB: in certain situations, psi.node could be null (see e.g. KT-44152)
 // Potentially exceptions can be provoked by elementType / lighterASTNode
 sealed class KtPsiSourceElement(val psi: PsiElement) : KtSourceElement() {
-    override val elementType: IElementType
+    override val elementType: IElementType?
-        get() = psi.node.elementType
+        get() = psi.node?.elementType
 
     override val startOffset: Int
         get() = psi.textRange.startOffset

compiler/testData/codegen/box/toArray/kt44152.kt

@@ -0,0 +1,17 @@
+// SKIP_JDK6
+// TARGET_BACKEND: JVM_IR
+// FULL_JDK
+// WITH_STDLIB
+// USE_PSI_CLASS_FILES_READING
+// Based on incorrectToArrayDetection.kt
+
+import java.lang.reflect.Modifier
+
+abstract class A : Collection<String> {
+    protected fun <T> foo(x: Array<T>): Array<T> = x
+}
+
+fun box(): String {
+    val method = A::class.java.declaredMethods.single { it.name == "foo" }
+    return if (Modifier.isProtected(method.modifiers)) "OK" else "Fail: $method"
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -46857,6 +46857,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/toArray/kt3177-toTypedArray.kt");
         }
 
+        @Test
+        @TestMetadata("kt44152.kt")
+        public void testKt44152() throws Exception {
+            runTest("compiler/testData/codegen/box/toArray/kt44152.kt");
+        }
+
         @Test
         @TestMetadata("returnToTypedArray.kt")
         public void testReturnToTypedArray() throws Exception {