Underlying constructor for type alias should always be substituted

Otherwise PSI2IR fails because of type mismatch.

compiler/backend/src/org/jetbrains/kotlin/codegen/state/KotlinTypeMapper.java

@@ -1117,7 +1117,7 @@ public class KotlinTypeMapper {
         }
 
         if (f instanceof TypeAliasConstructorDescriptor) {
-            return mapSignature(((TypeAliasConstructorDescriptor) f).getUnderlyingConstructorDescriptor(), kind, skipGenericSignature);
+            return mapSignature(((TypeAliasConstructorDescriptor) f).getUnderlyingConstructorDescriptor().getOriginal(), kind, skipGenericSignature);
         }
 
         if (f instanceof FunctionImportedFromObject) {

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/SymbolTable.kt

@@ -100,7 +100,8 @@ class SymbolTable {
         private var currentScope: Scope? = null
 
         override fun get(d: D): S? {
-            val scope = currentScope ?: throw AssertionError("No active scope")
+            val scope = currentScope
+                    ?: throw AssertionError("No active scope")
             return scope[d]
         }
 

compiler/testData/ir/irText/expressions/specializedTypeAliasConstructorCall.kt

@@ -0,0 +1,5 @@
+class Cell<T>(val value: T)
+
+typealias IntAlias = Cell<Int>
+
+fun test() = IntAlias(42)

compiler/testData/ir/irText/expressions/specializedTypeAliasConstructorCall.txt

@@ -0,0 +1,43 @@
+FILE fqName:<root> fileName:/specializedTypeAliasConstructorCall.kt
+  CLASS CLASS name:Cell modality:FINAL visibility:public flags:
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:Cell<T> flags:
+    superClasses:
+      CLASS IR_EXTERNAL_DECLARATION_STUB CLASS name:Any modality:OPEN visibility:public flags:
+    TYPE_PARAMETER name:T index:0 variance: upperBounds:[kotlin.Any?]
+      superClassifiers:
+        CLASS IR_EXTERNAL_DECLARATION_STUB CLASS name:Any modality:OPEN visibility:public flags:
+    CONSTRUCTOR visibility:public <> (value:T) returnType:Cell<T> flags:
+      VALUE_PARAMETER name:value index:0 type:T flags:
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'constructor Any()'
+        INSTANCE_INITIALIZER_CALL classDescriptor='Cell'
+    PROPERTY name:value type:T visibility:public modality:FINAL flags:val
+      FIELD PROPERTY_BACKING_FIELD name:value type:T visibility:public
+        EXPRESSION_BODY
+          GET_VAR 'value-parameter value: T' type=T origin=INITIALIZE_PROPERTY_FROM_PARAMETER
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-value> visibility:public modality:FINAL <> ($this:Cell<T>) returnType:T flags:
+        $this: VALUE_PARAMETER name:<this> type:Cell<T> flags:
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='<get-value>(): T'
+            GET_FIELD 'value: T' type=T origin=null
+              receiver: GET_VAR 'this@Cell: Cell<T>' type=Cell<T> origin=null
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:Boolean flags:
+      overridden:
+        FUN IR_EXTERNAL_DECLARATION_STUB name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:Boolean flags:
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any flags:
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any? flags:
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:Int flags:
+      overridden:
+        FUN IR_EXTERNAL_DECLARATION_STUB name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:Int flags:
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any flags:
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:String flags:
+      overridden:
+        FUN IR_EXTERNAL_DECLARATION_STUB name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:String flags:
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any flags:
+  TYPEALIAS typealias IntAlias = Cell<Int> type=Cell<kotlin.Int>
+  FUN name:test visibility:public modality:FINAL <> () returnType:Cell<Int> flags:
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='test(): IntAlias /* = Cell<Int> */'
+        CALL 'constructor Cell(Int)' type=Cell<kotlin.Int> origin=null
+          <T>: null
+          value: CONST Int type=kotlin.Int value=42

compiler/tests/org/jetbrains/kotlin/ir/IrTextTestCaseGenerated.java

@@ -951,6 +951,12 @@ public class IrTextTestCaseGenerated extends AbstractIrTextTestCase {
             doTest(fileName);
         }
 
+        @TestMetadata("specializedTypeAliasConstructorCall.kt")
+        public void testSpecializedTypeAliasConstructorCall() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/ir/irText/expressions/specializedTypeAliasConstructorCall.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("stringComparisons.kt")
         public void testStringComparisons() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/ir/irText/expressions/stringComparisons.kt");

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/FunctionDescriptorImpl.java

@@ -599,6 +599,7 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
         final TypeSubstitutor substitutor = DescriptorSubstitutor.substituteTypeParameters(
                 unsubstitutedTypeParameters, configuration.substitution, substitutedDescriptor, substitutedTypeParameters, wereChanges
         );
+        if (substitutor == null) return null;
 
         KotlinType substitutedReceiverParameterType = null;
         if (configuration.newExtensionReceiverParameterType != null) {
@@ -768,6 +769,15 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
         return visitor.visitFunctionDescriptor(this, data);
     }
 
+    @Nullable
+    public static List<ValueParameterDescriptor> getSubstitutedValueParameters(
+            FunctionDescriptor substitutedDescriptor,
+            @NotNull List<ValueParameterDescriptor> unsubstitutedValueParameters,
+            @NotNull TypeSubstitutor substitutor
+    ) {
+        return getSubstitutedValueParameters(substitutedDescriptor, unsubstitutedValueParameters, substitutor, false, false, null);
+    }
+
     @Nullable
     public static List<ValueParameterDescriptor> getSubstitutedValueParameters(
             FunctionDescriptor substitutedDescriptor,

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/TypeAliasConstructorDescriptor.kt

@@ -175,27 +175,26 @@ class TypeAliasConstructorDescriptorImpl private constructor(
             constructor: ClassConstructorDescriptor
         ): TypeAliasConstructorDescriptor? {
             val substitutorForUnderlyingClass = typeAliasDescriptor.getTypeSubstitutorForUnderlyingClass() ?: return null
+            val substitutedConstructor = constructor.substitute(substitutorForUnderlyingClass) ?: return null
 
             val typeAliasConstructor =
                 TypeAliasConstructorDescriptorImpl(
-                    storageManager, typeAliasDescriptor, constructor, null, constructor.annotations,
+                    storageManager, typeAliasDescriptor,
+                    substitutedConstructor,
+                    null, constructor.annotations,
                     constructor.kind, typeAliasDescriptor.source
                 )
 
             val valueParameters =
                 FunctionDescriptorImpl.getSubstitutedValueParameters(
-                    typeAliasConstructor, constructor.valueParameters, substitutorForUnderlyingClass, false, false,
+                    typeAliasConstructor, constructor.valueParameters, substitutorForUnderlyingClass
-                    null
                 ) ?: return null
 
-            val returnType = run {
+            val returnType = substitutedConstructor.returnType.unwrap().lowerIfFlexible().withAbbreviation(typeAliasDescriptor.defaultType)
-                val returnTypeNoAbbreviation = substitutorForUnderlyingClass.substitute(constructor.returnType, Variance.INVARIANT)
-                        ?: return null
-                returnTypeNoAbbreviation.unwrap().lowerIfFlexible().withAbbreviation(typeAliasDescriptor.defaultType)
-            }
 
-            val receiverParameterType =
+            val receiverParameterType = constructor.dispatchReceiverParameter?.let {
-                constructor.dispatchReceiverParameter?.let { substitutorForUnderlyingClass.safeSubstitute(it.type, Variance.INVARIANT) }
+                substitutorForUnderlyingClass.safeSubstitute(it.type, Variance.INVARIANT)
+            }
 
             typeAliasConstructor.initialize(
                 receiverParameterType,

core/descriptors/src/org/jetbrains/kotlin/types/DescriptorSubstitutor.java

@@ -40,10 +40,12 @@ public class DescriptorSubstitutor {
             @NotNull DeclarationDescriptor newContainingDeclaration,
             @NotNull @Mutable List<TypeParameterDescriptor> result
     ) {
-        return substituteTypeParameters(typeParameters, originalSubstitution, newContainingDeclaration, result, null);
+        TypeSubstitutor substitutor = substituteTypeParameters(typeParameters, originalSubstitution, newContainingDeclaration, result, null);
+        if (substitutor == null) throw new AssertionError("Substitution failed");
+        return substitutor;
     }
 
-    @NotNull
+    @Nullable
     public static TypeSubstitutor substituteTypeParameters(
             @ReadOnly @NotNull List<TypeParameterDescriptor> typeParameters,
             @NotNull TypeSubstitution originalSubstitution,
@@ -80,7 +82,7 @@ public class DescriptorSubstitutor {
             TypeParameterDescriptorImpl substituted = substitutedMap.get(descriptor);
             for (KotlinType upperBound : descriptor.getUpperBounds()) {
                 KotlinType substitutedBound = substitutor.substitute(upperBound, Variance.IN_VARIANCE);
-                assert substitutedBound != null : "Upper bound failed to substitute: " + descriptor;
+                if (substitutedBound == null) return null;
 
                 if (substitutedBound != upperBound && wereChanges != null) {
                     wereChanges[0] = true;