Fix PSI behavior for "val x : ()?' case

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/TypeTransformingVisitor.java

@@ -76,7 +76,9 @@ public class TypeTransformingVisitor extends JetVisitor<JetType, Void> {
             throw new AlternativeSignatureMismatchException("Auto type '%s' is not-null, while type in alternative signature is nullable: '%s'",
                  DescriptorRenderer.TEXT.renderType(originalType), nullableType.getText());
         }
-        return TypeUtils.makeNullable(computeType(nullableType.getInnerType(), originalType, originalToAltTypeParameters, typeUsage));
+        JetTypeElement innerType = nullableType.getInnerType();
+        assert innerType != null : "Syntax error: " + nullableType.getText();
+        return TypeUtils.makeNullable(computeType(innerType, originalType, originalToAltTypeParameters, typeUsage));
     }
 
     @Override

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNullableType.java

@@ -18,8 +18,10 @@ package org.jetbrains.jet.lang.psi;
 
 import com.intellij.lang.ASTNode;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lexer.JetTokens;
 
+import java.util.Collections;
 import java.util.List;
 
 public class JetNullableType extends JetTypeElement {
@@ -35,7 +37,8 @@ public class JetNullableType extends JetTypeElement {
     @NotNull
     @Override
     public List<JetTypeReference> getTypeArgumentsAsTypes() {
-        return getInnerType().getTypeArgumentsAsTypes();
+        JetTypeElement innerType = getInnerType();
+        return innerType == null ? Collections.<JetTypeReference>emptyList() : innerType.getTypeArgumentsAsTypes();
     }
 
     @Override
@@ -43,7 +46,8 @@ public class JetNullableType extends JetTypeElement {
         return visitor.visitNullableType(this, data);
     }
 
-    @NotNull
+    @Nullable
+    @IfNotParsed
     public JetTypeElement getInnerType() {
         return findChildByClass(JetTypeElement.class);
     }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/DescriptorResolver.java

@@ -241,7 +241,7 @@ public class DescriptorResolver {
             JetNullableType nullableType = (JetNullableType) typeElement;
             typeElement = nullableType.getInnerType();
             // report only for innermost '?', the rest gets a 'redundant' warning
-            if (!(typeElement instanceof JetNullableType)) {
+            if (!(typeElement instanceof JetNullableType) && typeElement != null) {
                 trace.report(NULLABLE_SUPERTYPE.on(nullableType));
             }
         }

compiler/testData/psi/AbsentInnerType.kt

@@ -0,0 +1 @@
+val x: ()? = 1

compiler/testData/psi/AbsentInnerType.txt

@@ -0,0 +1,21 @@
+JetFile: AbsentInnerType.kt
+  PACKAGE_DIRECTIVE
+    <empty list>
+  PROPERTY
+    PsiElement(val)('val')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('x')
+    PsiElement(COLON)(':')
+    PsiWhiteSpace(' ')
+    TYPE_REFERENCE
+      NULLABLE_TYPE
+        PsiElement(LPAR)('(')
+        PsiErrorElement:Type expected
+          <empty list>
+        PsiElement(RPAR)(')')
+        PsiElement(QUEST)('?')
+    PsiWhiteSpace(' ')
+    PsiElement(EQ)('=')
+    PsiWhiteSpace(' ')
+    INTEGER_CONSTANT
+      PsiElement(INTEGER_LITERAL)('1')

compiler/tests/org/jetbrains/jet/parsing/JetParsingTestGenerated.java

@@ -33,6 +33,11 @@ import org.jetbrains.jet.parsing.AbstractJetParsingTest;
 @TestMetadata("compiler/testData/psi")
 @InnerTestClasses({JetParsingTestGenerated.Examples.class, JetParsingTestGenerated.FunctionReceivers.class, JetParsingTestGenerated.GreatSyntacticShift.class, JetParsingTestGenerated.Kdoc.class, JetParsingTestGenerated.PropertyDelegate.class, JetParsingTestGenerated.Recovery.class, JetParsingTestGenerated.StringTemplates.class})
 public class JetParsingTestGenerated extends AbstractJetParsingTest {
+    @TestMetadata("AbsentInnerType.kt")
+    public void testAbsentInnerType() throws Exception {
+        doParsingTest("compiler/testData/psi/AbsentInnerType.kt");
+    }
+    
     public void testAllFilesPresentInPsi() throws Exception {
         JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.TestsPackage", new File("compiler/testData/psi"), Pattern.compile("^(.+)\\.kt$"), true);
     }