Java to Kotlin converter: correct code generated for accessing nullable variables

j2k/src/org/jetbrains/jet/j2k/TypeConverter.kt

@@ -38,6 +38,12 @@ class TypeConverter(val settings: ConverterSettings) {
     }
 
     public fun convertVariableType(variable: PsiVariable): Type {
+        return convertType(variable.getType(), variableNullability(variable))
+    }
+
+    public fun variableNullability(variable: PsiVariable): Nullability {
+        if (variable is PsiEnumConstant) return Nullability.NotNull
+
         var nullability = variable.nullabilityFromAnnotations()
 
         if (nullability == Nullability.Default) {
@@ -82,7 +88,7 @@ class TypeConverter(val settings: ConverterSettings) {
             }
         }
 
-        return convertType(variable.getType(), nullability)
+        return nullability
     }
 
     public fun convertMethodReturnType(method: PsiMethod): Type {
@@ -160,7 +166,7 @@ class TypeConverter(val settings: ConverterSettings) {
             }
         }
         else if (parent is PsiVariable && usage == parent.getInitializer() && parent.isEffectivelyFinal()) {
-            return convertVariableType(parent).isNullable
+            return variableNullability(parent) == Nullability.Nullable
         }
         return false
     }

j2k/src/org/jetbrains/jet/j2k/ast/Types.kt

@@ -74,7 +74,7 @@ trait Type : Element {
     override fun toString(): String = toKotlin()
 }
 
-open class ClassType(val `type`: Identifier, val parameters: List<Element>, nullability: Nullability, settings: ConverterSettings)
+class ClassType(val `type`: Identifier, val parameters: List<Element>, nullability: Nullability, settings: ConverterSettings)
   : MayBeNullableType(nullability, settings) {
 
     override fun toKotlin(): String {
@@ -110,22 +110,22 @@ class ArrayType(val elementType: Type, nullability: Nullability, settings: Conve
     override fun toNullableType(): Type = ArrayType(elementType, Nullability.Nullable, settings)
 }
 
-open class InProjectionType(val bound: Type) : NotNullType {
+class InProjectionType(val bound: Type) : NotNullType {
     override fun toKotlin(): String = "in " + bound.toKotlin()
 }
 
-open class OutProjectionType(val bound: Type) : NotNullType {
+class OutProjectionType(val bound: Type) : NotNullType {
     override fun toKotlin(): String = "out " + bound.toKotlin()
 }
 
-open class StarProjectionType() : NotNullType {
+class StarProjectionType() : NotNullType {
     override fun toKotlin(): String = "*"
 }
 
-open class PrimitiveType(val `type`: Identifier) : NotNullType {
+class PrimitiveType(val `type`: Identifier) : NotNullType {
     override fun toKotlin(): String = `type`.toKotlin()
 }
 
-open class VarArgType(val `type`: Type) : NotNullType {
+class VarArgType(val `type`: Type) : NotNullType {
     override fun toKotlin(): String = `type`.toKotlin()
 }

j2k/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.kt

@@ -358,8 +358,7 @@ class ExpressionVisitor(private val converter: Converter,
     private fun PsiReference.nullability(): Nullability {
         val target = resolve()
         return when(target) {
-            is PsiEnumConstant -> Nullability.NotNull
-            is PsiModifierListOwner -> target.nullabilityFromAnnotations()
+            is PsiVariable -> typeConverter.variableNullability(target)
             else -> Nullability.Default
         }
     }

j2k/tests/test/org/jetbrains/jet/j2k/test/JavaToKotlinConverterTestGenerated.java

@@ -16,17 +16,14 @@
 
 package org.jetbrains.jet.j2k.test;
 
-import junit.framework.Assert;
 import junit.framework.Test;
 import junit.framework.TestSuite;
-
-import java.io.File;
-import java.util.regex.Pattern;
 import org.jetbrains.jet.JetTestUtils;
 import org.jetbrains.jet.test.InnerTestClasses;
 import org.jetbrains.jet.test.TestMetadata;
 
-import org.jetbrains.jet.j2k.test.AbstractJavaToKotlinConverterTest;
+import java.io.File;
+import java.util.regex.Pattern;
 
 /** This class is generated by {@link org.jetbrains.jet.generators.tests.TestsPackage}. DO NOT MODIFY MANUALLY */
 @SuppressWarnings("all")
@@ -1961,6 +1958,11 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             doTest("j2k/tests/testData/ast/nullability/MethodReturnsTernaryNull.java");
         }
         
+        @TestMetadata("NullableVariableDotAccess.java")
+        public void testNullableVariableDotAccess() throws Exception {
+            doTest("j2k/tests/testData/ast/nullability/NullableVariableDotAccess.java");
+        }
+        
         @TestMetadata("ParameterComparedWithNull.java")
         public void testParameterComparedWithNull() throws Exception {
             doTest("j2k/tests/testData/ast/nullability/ParameterComparedWithNull.java");

j2k/tests/testData/ast/callChainExpression/libraryMethodCallFromInstance-settings.kt

@@ -12,8 +12,8 @@ class Library() {
 class User() {
     fun main() {
         val lib: Library = Library()
-        lib?.call()
-        lib?.getString()?.isEmpty()
+        lib.call()
+        lib.getString()?.isEmpty()
 
         Library().call()
         Library().getString()?.isEmpty()

j2k/tests/testData/ast/issues/kt-824-isDir.kt

@@ -8,11 +8,11 @@ import java.io.File
 public class Test() {
     class object {
         public fun isDir(parent: File?): Boolean {
-            if (parent == null || !parent.exists()) {
+            if (parent == null || !parent?.exists()!!) {
                 return false
             }
             val result = true
-            if (parent.isDirectory()) {
+            if (parent?.isDirectory()!!) {
                 return true
             } else
                 return false

j2k/tests/testData/ast/nullability/NullableVariableDotAccess.java

@@ -0,0 +1,6 @@
+//method
+int foo(String s, boolean b) {
+  if (s == null) System.out.println("null")
+  if (b) return s.length();
+  return 10;
+}

j2k/tests/testData/ast/nullability/NullableVariableDotAccess.kt

@@ -0,0 +1,7 @@
+fun foo(s: String?, b: Boolean): Int {
+    if (s == null)
+        System.out.println("null")
+    if (b)
+        return s?.length()!!
+    return 10
+}

j2k/tests/testData/ast/prefixOperator/nullableIf.kt

@@ -1,3 +1,3 @@
 val s = null
-if (!s.isEmpty()) {
+if (!s?.isEmpty()!!) {
 }