Fix NPE in data class 'equals' codegen

Do not perform the optimization from 0a11385006 for data class
properties of nullable types

compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java

@@ -52,6 +52,7 @@ import org.jetbrains.kotlin.resolve.scopes.receivers.ExtensionReceiver;
 import org.jetbrains.kotlin.resolve.scopes.receivers.ImplicitReceiver;
 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue;
 import org.jetbrains.kotlin.types.KotlinType;
+import org.jetbrains.kotlin.types.TypeUtils;
 import org.jetbrains.org.objectweb.asm.FieldVisitor;
 import org.jetbrains.org.objectweb.asm.Label;
 import org.jetbrains.org.objectweb.asm.MethodVisitor;
@@ -577,7 +578,13 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                     if (isPrimitive(asmType)) {
                         StackValue value = StackValue.cmp(KtTokens.EQEQ, asmType, StackValue.onStack(asmType), StackValue.onStack(asmType));
                         value.put(Type.BOOLEAN_TYPE, iv);
-                    } else {
+                    }
+                    else if (TypeUtils.isNullableType(propertyDescriptor.getType())) {
+                        StackValue value =
+                                genEqualsForExpressionsOnStack(KtTokens.EQEQ, StackValue.onStack(asmType), StackValue.onStack(asmType));
+                        value.put(Type.BOOLEAN_TYPE, iv);
+                    }
+                    else {
                         Type owner =
                                 DescriptorUtils.isInterface(propertyDescriptor.getType().getConstructor().getDeclarationDescriptor())
                                 ? AsmTypes.OBJECT_TYPE

compiler/testData/codegen/box/dataClasses/equals/null.kt

@@ -0,0 +1,15 @@
+data class A(val v: Any?)
+
+data class B<T>(val v: T)
+
+fun box(): String {
+    val a1 = A(null)
+    val a2 = A("")
+    if (a1 == a2 || a2 == a1) return "Fail 1"
+
+    val b1 = B(null)
+    val b2 = B("")
+    if (b1 == b2 || b2 == b1) return "Fail 2"
+
+    return "OK"
+}

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -7230,6 +7230,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 doTest(fileName);
             }
 
+            @TestMetadata("null.kt")
+            public void testNull() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/dataClasses/equals/null.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("nullother.kt")
             public void testNullother() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/dataClasses/equals/nullother.kt");

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

@@ -7230,6 +7230,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("null.kt")
+            public void testNull() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/dataClasses/equals/null.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("nullother.kt")
             public void testNullother() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/dataClasses/equals/nullother.kt");

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

@@ -7230,6 +7230,12 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 doTest(fileName);
             }
 
+            @TestMetadata("null.kt")
+            public void testNull() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/dataClasses/equals/null.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("nullother.kt")
             public void testNullother() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/dataClasses/equals/nullother.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -8563,6 +8563,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("null.kt")
+            public void testNull() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/dataClasses/equals/null.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("nullother.kt")
             public void testNullother() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/dataClasses/equals/nullother.kt");