Typealias can't be a qualifier

compiler/frontend/src/org/jetbrains/kotlin/resolve/QualifiedExpressionResolver.kt

@@ -397,7 +397,7 @@ class QualifiedExpressionResolver(val classifierUsageCheckers: Iterable<Classifi
             val nextPackageOrClassDescriptor =
                     when (currentDescriptor) {
                         is TypeAliasDescriptor -> // TODO type aliases as qualifiers? (would break some assumptions in TypeResolver)
-                            currentDescriptor.classDescriptor?.getContributedClassifier(qualifierPart)
+                            null
                         is ClassDescriptor ->
                             currentDescriptor.getContributedClassifier(qualifierPart)
                         is PackageViewDescriptor -> {
@@ -622,7 +622,6 @@ class QualifiedExpressionResolver(val classifierUsageCheckers: Iterable<Classifi
                     is PackageViewDescriptor -> PackageQualifier(referenceExpression, descriptor)
                     is ClassDescriptor -> ClassQualifier(referenceExpression, descriptor)
                     is TypeParameterDescriptor -> TypeParameterQualifier(referenceExpression, descriptor)
-                    is TypeAliasDescriptor -> ClassQualifier(referenceExpression, descriptor.classDescriptor ?: return null)
                     else -> return null
                 }
 

compiler/testData/diagnostics/tests/typealias/typeAliasAsQualifier.kt

@@ -0,0 +1,18 @@
+class C {
+    typealias Self = C
+    class Nested {
+        class N2
+        typealias Root = C
+    }
+    companion object X {
+        val ok = "OK"
+        class InCompanion
+    }
+}
+
+val c = C.Self.<!UNRESOLVED_REFERENCE!>Self<!>()
+val n = C.Self.<!UNRESOLVED_REFERENCE!>Nested<!>()
+val x = C.Self.<!UNRESOLVED_REFERENCE!>X<!>
+val n2 = C.Nested.Root.<!UNRESOLVED_REFERENCE!>Nested<!>.<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>N2<!>()
+val ic = C.Self.<!UNRESOLVED_REFERENCE!>InCompanion<!>()
+val ok = C.Self.ok

compiler/testData/diagnostics/tests/typealias/typeAliasAsQualifier.txt

@@ -0,0 +1,46 @@
+package
+
+public val c: [ERROR : Type for C.Self.Self()]
+public val ic: [ERROR : Type for C.Self.InCompanion()]
+public val n: [ERROR : Type for C.Self.Nested()]
+public val n2: [ERROR : <ERROR FUNCTION RETURN TYPE>]
+public val ok: kotlin.String = "OK"
+public val x: [ERROR : Type for C.Self.X]
+
+public final class C {
+    public typealias Self = C
+    public constructor C()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public final class Nested {
+        public typealias Root = C
+        public constructor Nested()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        public final class N2 {
+            public constructor N2()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+
+    public companion object X {
+        private constructor X()
+        public final val ok: kotlin.String = "OK"
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        public final class InCompanion {
+            public constructor InCompanion()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -19821,6 +19821,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("typeAliasAsQualifier.kt")
+            public void testTypeAliasAsQualifier() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typealias/typeAliasAsQualifier.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("typeAliasConstructor.kt")
             public void testTypeAliasConstructor() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typealias/typeAliasConstructor.kt");