[NI] Make subtyping algorithm more robust to error types

During subtyping/incorporation we transform types (e.g. changing nullability,
 form of the type) and, basically, we're doing this to some FIXPOINT.
 It's important that we use `KotlinType.hashCode()` to compare types, but
 for error types hashCode is a hashCode of its supertype and, for example,
 `makeNullableAsSpecified` method recreate type every time. So, we continue
 to generate new constraints and we'll never stop incorporation algorithm

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/ConstraintInjector.kt

@@ -154,6 +154,11 @@ class ConstraintInjector(val constraintIncorporator: ConstraintIncorporator, val
                     ?: error("Should by type variableConstructor: $typeVariableConstructor. ${c.allTypeVariables.values}")
 
             var targetType = type
+            if (targetType.isError) {
+                c.addError(ConstrainingTypeIsError(typeVariable, targetType, position))
+                return
+            }
+
             if (type.contains(this::isCapturedTypeFromSubtyping)) {
                 // TypeVariable <: type -> if TypeVariable <: subType => TypeVariable <: type
                 if (kind == UPPER) {

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/ConstraintPositionAndErrors.kt

@@ -93,3 +93,9 @@ class CapturedTypeFromSubtyping(
 ) : ConstraintSystemCallDiagnostic(INAPPLICABLE)
 
 class NotEnoughInformationForTypeParameter(val typeVariable: NewTypeVariable) : ConstraintSystemCallDiagnostic(INAPPLICABLE)
+
+class ConstrainingTypeIsError(
+    val typeVariable: NewTypeVariable,
+    val constraintType: UnwrappedType,
+    val position: IncorporationConstraintPosition
+) : ConstraintSystemCallDiagnostic(INAPPLICABLE)

compiler/testData/diagnostics/tests/cast/bare/UnrelatedColon.ni.txt

@@ -1,6 +1,6 @@
 package
 
-public fun test(/*0*/ tr: Tr): [ERROR : G]
+public fun test(/*0*/ tr: Tr): Tr
 
 public interface G</*0*/ T> {
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean

compiler/testData/diagnostics/tests/controlFlowAnalysis/unresolvedReference.kt

@@ -1,4 +1,3 @@
-// !WITH_NEW_INFERENCE
 // See KT-6665: unresolved reference (v.bar) should not produce "unreachable code" after it
 
 fun foo(): Int {
@@ -29,14 +28,14 @@ fun foo3(): Int {
 fun bar(): Int {
     val v = 1
     val c = v.<!UNRESOLVED_REFERENCE!>bar<!> ?: 42
-    return <!NI;DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>c<!>
+    return c
 }
 
 fun bar2(): Int {
     val v = 1
     val c = if (true) v.<!UNRESOLVED_REFERENCE!>bar<!> else 3
-    val b = <!NI;DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>c<!>
+    val b = c
-    return <!NI;DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>b<!>
+    return b
 }
 
 fun bar3(): Int {
@@ -45,6 +44,6 @@ fun bar3(): Int {
         true -> v.<!UNRESOLVED_REFERENCE!>bar<!>
         else -> 3
     }
-    val b = <!NI;DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>c<!>
+    val b = c
-    return <!NI;DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>b<!>
+    return b
 }

compiler/testData/diagnostics/tests/delegatedProperty/inference/genericMethods.kt

@@ -1,10 +1,9 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
-// !WITH_NEW_INFERENCE
 // NI_EXPECTED_FILE
 import kotlin.reflect.KProperty
 
 var a: Int by A()
-var a1 by <!OI;DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE, DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>A()<!>
+var a1 by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE, DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>A()<!>
 
 var b: Int by B()
 

compiler/testData/diagnostics/tests/functionLiterals/return/ForbiddenNonLocalReturnNoType.kt

@@ -1,18 +1,18 @@
 // !WITH_NEW_INFERENCE
 fun test() {
     run {<!RETURN_NOT_ALLOWED!>return<!>}
-    run {}
+    <!NI;UNREACHABLE_CODE!>run {}<!>
 }
 
 fun test2() {
     run {<!RETURN_NOT_ALLOWED!>return@test2<!>}
-    run {}
+    <!NI;UNREACHABLE_CODE!>run {}<!>
 }
 
 fun test3() {
     fun test4() {
         run {<!RETURN_NOT_ALLOWED!>return@test3<!>}
-        run {}
+        <!NI;UNREACHABLE_CODE!>run {}<!>
     }
 }
 

compiler/testData/diagnostics/tests/inference/constraints/errorUpperBoundConstraint.kt

@@ -0,0 +1,26 @@
+// !LANGUAGE: +NewInference
+
+// FILE: Sam.java
+
+public interface Sam<K> {
+    Sam.Result<K> compute();
+
+    public static class Result<V> {
+        public static <V> Sam.Result<V> create(V value) {}
+    }
+}
+
+// FILE: Foo.java
+
+public class Foo {
+    public static <T> void foo(Sam<T> var1) {
+    }
+}
+
+// FILE: test.kt
+
+fun test(e: <!UNRESOLVED_REFERENCE!>ErrorType<!>) {
+    Foo.foo {
+        Sam.Result.create(<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>e<!>)
+    }
+}

compiler/testData/diagnostics/tests/inference/constraints/errorUpperBoundConstraint.txt

@@ -0,0 +1,30 @@
+package
+
+public fun test(/*0*/ e: [ERROR : ErrorType]): kotlin.Unit
+
+public open class Foo {
+    public constructor Foo()
+    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
+
+    // Static members
+    public open fun </*0*/ T : kotlin.Any!> foo(/*0*/ var1: Sam<T!>!): kotlin.Unit
+}
+
+public interface Sam</*0*/ K : kotlin.Any!> {
+    public abstract fun compute(): Sam.Result<K!>!
+    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 open class Result</*0*/ V : kotlin.Any!> {
+        public constructor Result</*0*/ V : kotlin.Any!>()
+        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
+
+        // Static members
+        public open fun </*0*/ V : kotlin.Any!> create(/*0*/ value: V!): Sam.Result<V!>!
+    }
+}

compiler/testData/diagnostics/tests/inference/nestedCalls/binaryExpressions.kt

@@ -57,7 +57,7 @@ fun test3(z: Z) {
 //'in' operation
 fun test4(collection: Collection<A<*>>) {
     id(<!OI;TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>newA<!>() in collection)
-    id(newA<Int>() in collection)
+    <!NI;UNREACHABLE_CODE!>id(newA<Int>() in collection)<!>
 }
 
 //boolean operations

compiler/testData/diagnostics/tests/inference/recursiveLocalFuns/selfCall.kt

@@ -3,7 +3,7 @@ fun foo() {
     fun bar1() = <!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!><!NI;DEBUG_INFO_MISSING_UNRESOLVED!>bar1<!>()<!>
 
     fun bar2() = 1 <!NI;OVERLOAD_RESOLUTION_AMBIGUITY!>+<!> <!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!><!NI;DEBUG_INFO_MISSING_UNRESOLVED!>bar2<!>()<!>
-    fun bar3() = id(<!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!><!NI;DEBUG_INFO_MISSING_UNRESOLVED!>bar3<!>()<!>)
+    fun <!NI;IMPLICIT_NOTHING_RETURN_TYPE!>bar3<!>() = id(<!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!><!NI;DEBUG_INFO_MISSING_UNRESOLVED!>bar3<!>()<!>)
 }
 
 fun <T> id(x: T) = x

compiler/testData/diagnostics/tests/platformTypes/nullabilityWarnings/elvis.kt

@@ -1,5 +1,4 @@
 // !DIAGNOSTICS: -UNUSED_VARIABLE -SENSELESS_COMPARISON, -UNUSED_PARAMETER
-// !WITH_NEW_INFERENCE
 
 // FILE: J.java
 
@@ -62,7 +61,7 @@ fun test() {
     takeNotNull(J.getNAny() ?: J())
 
     val x = <!UNRESOLVED_REFERENCE!>unresolved<!> ?: null
-    <!OI;UNREACHABLE_CODE!>val y =<!> <!UNRESOLVED_REFERENCE!>unresolved<!>.<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>foo<!> ?: return
+    <!UNREACHABLE_CODE!>val y =<!> <!UNRESOLVED_REFERENCE!>unresolved<!>.<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>foo<!> ?: return
 }
 
 fun takeNotNull(s: J) {}

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/recursiveGetter.kt

@@ -10,7 +10,7 @@ class A {
     val a get() = <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>b<!>
     val b get() = <!NI;DEBUG_INFO_MISSING_UNRESOLVED, TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>a<!>
 
-    val z1 get() = id(<!NI;DEBUG_INFO_MISSING_UNRESOLVED, OI;DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE, TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>z1<!>)
+    val <!NI;IMPLICIT_NOTHING_PROPERTY_TYPE!>z1<!> get() = id(<!NI;DEBUG_INFO_MISSING_UNRESOLVED, OI;DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE, TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>z1<!>)
     val z2 get() = l(<!NI;DEBUG_INFO_MISSING_UNRESOLVED, OI;DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE, TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>z2<!>)
 
     val u get() = <!UNRESOLVED_REFERENCE!>field<!>

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/recursiveGetter.ni.txt

@@ -10,8 +10,8 @@ public final class A {
     public final val b: [ERROR : Error function type]
     public final val u: [ERROR : Error function type]
     public final val y: [ERROR : Error function type]
-    public final val z1: [ERROR : Error type for ParseError-argument VALUE_ARGUMENT]
+    public final val z1: kotlin.Nothing
-    public final val z2: kotlin.collections.List<[ERROR : Error type for ParseError-argument VALUE_ARGUMENT]>
+    public final val z2: kotlin.collections.List<kotlin.Nothing>
     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

@@ -9565,6 +9565,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     runTest("compiler/testData/diagnostics/tests/inference/constraints/equalityConstraintOnNullableType.kt");
                 }
 
+                @TestMetadata("errorUpperBoundConstraint.kt")
+                public void testErrorUpperBoundConstraint() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/constraints/errorUpperBoundConstraint.kt");
+                }
+
                 @TestMetadata("ignoreConstraintFromImplicitInNothing.kt")
                 public void testIgnoreConstraintFromImplicitInNothing() throws Exception {
                     runTest("compiler/testData/diagnostics/tests/inference/constraints/ignoreConstraintFromImplicitInNothing.kt");

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -9565,6 +9565,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                     runTest("compiler/testData/diagnostics/tests/inference/constraints/equalityConstraintOnNullableType.kt");
                 }
 
+                @TestMetadata("errorUpperBoundConstraint.kt")
+                public void testErrorUpperBoundConstraint() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/constraints/errorUpperBoundConstraint.kt");
+                }
+
                 @TestMetadata("ignoreConstraintFromImplicitInNothing.kt")
                 public void testIgnoreConstraintFromImplicitInNothing() throws Exception {
                     runTest("compiler/testData/diagnostics/tests/inference/constraints/ignoreConstraintFromImplicitInNothing.kt");