Revert "NI: Prefer nullable lower bound to flexible one when substitution of type variable is performed ^KT-32435 Fixed"

This reverts commit 09c2b92b

compiler/fir/resolve/testData/resolve/arguments/lambdaInLambda2.kt

@@ -20,7 +20,7 @@ interface PsiMethod {
 interface PsiClass
 
 fun test() {
-    val processor = AdapterProcessor<PsiMethod, PsiClass?>(
+    val processor = AdapterProcessor<PsiMethod, PsiClass>(
         Function { method: PsiMethod? -> method?.containingClass }
     )
 }

compiler/fir/resolve/testData/resolve/arguments/lambdaInLambda2.txt

@@ -7,7 +7,7 @@ FILE: main.kt
     public abstract interface PsiClass : R|kotlin/Any| {
     }
     public final fun test(): R|kotlin/Unit| {
-        lval processor: R|AdapterProcessor<PsiMethod, PsiClass?>| = R|/AdapterProcessor.AdapterProcessor|<R|PsiMethod|, R|PsiClass?|>(R|/Function|<R|PsiMethod|, R|PsiClass?|>(<L> = Function@fun <anonymous>(method: R|PsiMethod?|): R|PsiClass?| {
+        lval processor: R|AdapterProcessor<PsiMethod, PsiClass>| = R|/AdapterProcessor.AdapterProcessor|<R|PsiMethod|, R|PsiClass|>(R|/Function|<R|PsiMethod|, R|ft<PsiClass, PsiClass?>!|>(<L> = Function@fun <anonymous>(method: R|PsiMethod?|): R|PsiClass?| {
             R|<local>/method|?.R|/PsiMethod.containingClass|
         }
         ))

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsSmokeTestGenerated.java

@@ -14635,11 +14635,6 @@ public class FirDiagnosticsSmokeTestGenerated extends AbstractFirDiagnosticsSmok
             runTest("compiler/testData/diagnostics/tests/nullableTypes/elvisOnUnit.kt");
         }
 
-        @TestMetadata("inferenceFlexibleTToNullable.kt")
-        public void testInferenceFlexibleTToNullable() throws Exception {
-            runTest("compiler/testData/diagnostics/tests/nullableTypes/inferenceFlexibleTToNullable.kt");
-        }
-
         @TestMetadata("nullAssertOnTypeWithNullableUpperBound.kt")
         public void testNullAssertOnTypeWithNullableUpperBound() throws Exception {
             runTest("compiler/testData/diagnostics/tests/nullableTypes/nullAssertOnTypeWithNullableUpperBound.kt");

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

@@ -136,7 +136,7 @@ abstract class AbstractTypeCheckerContextForConstraintSystem : AbstractTypeCheck
      *
      * => Foo <: T! -- (Foo!! .. Foo) <: T
      *
-     * Foo? <: T! -- Foo? <: T
+     * Foo? <: T! -- (Foo!! .. Foo?) <: T
      *
      *
      * (Foo..Bar) <: T! --
@@ -163,11 +163,7 @@ abstract class AbstractTypeCheckerContextForConstraintSystem : AbstractTypeCheck
                 when (subType) {
                     is SimpleTypeMarker ->
                         // Foo <: T! -- (Foo!! .. Foo) <: T
-                        if (subType.isNullableType()) {
+                        createFlexibleType(subType.makeSimpleTypeDefinitelyNotNullOrNotNull(), subType)
-                            subType // prefer nullable type to flexible one: `Foo? <: (T..T?)` => lowerConstraint = `Foo?`
-                        } else {
-                            createFlexibleType(subType.makeSimpleTypeDefinitelyNotNullOrNotNull(), subType)
-                        }
 
                     is FlexibleTypeMarker ->
                         // (Foo..Bar) <: T! -- (Foo!! .. Bar) <: T

compiler/testData/codegen/box/platformTypes/inferenceFlexibleTToNullable.kt

@@ -1,71 +0,0 @@
-// !LANGUAGE: +NewInference
-
-// FILE: Foo.java
-import org.jetbrains.annotations.NotNull;
-
-public class Foo<T>  {
-    T x;
-
-    public Foo(T x) {
-        this.x = x;
-    }
-
-    public static Number bar() { return null; }
-
-    public static <K> K simpleId(K k) {
-        return k;
-    }
-
-    public T produceT() {
-        return x;
-    }
-
-    @NotNull
-    public T produceNotNullT() {
-        return x;
-    }
-
-    public void consumeT(T x) {}
-}
-
-// FILE: main.kt
-fun <T> bar(n: Number?, d: T, e: T) {
-    val b: Number? = Foo.simpleId(n)
-    b?.toInt()
-    val c = Foo.simpleId(n)
-    c?.toInt()
-
-    val x4 = Foo(if (true) 10 else null)
-    val x6: Number? = x4.produceT()
-    x6?.toInt()
-    val x7 = x4.produceT()
-    x7?.toInt()
-    val x8 = x4.produceNotNullT()
-    x8.toInt()
-
-    x4.consumeT(x7)
-
-    val x9: T = Foo.simpleId(d)
-    val x10: T? = Foo.simpleId(d)
-
-    if (e != null) {
-        var x11 = e
-        x11 = Foo.simpleId(d) // assign to definitely not-null T, the lack an error is consistent with old inference
-    }
-
-    var x11 = Foo<T>(e).x
-    x11 = Foo.simpleId(d) // assign to flexible T
-
-    var x12 = Foo.bar()
-    x12 = Foo.simpleId(n) // assign to flexible Number
-    x12.toInt()
-
-    var x13 = e
-    x13 = Foo.simpleId(d)
-}
-
-fun box(): String {
-    bar(10, "", "")
-
-    return "OK"
-}

compiler/testData/diagnostics/tests/nullableTypes/inferenceFlexibleTToNullable.kt

@@ -1,63 +0,0 @@
-// !DIAGNOSTICS: -UNUSED_VARIABLE -UNCHECKED_CAST -UNUSED_VALUE -ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE
-// !LANGUAGE: +NewInference
-// SKIP_TXT
-
-// FILE: Foo.java
-import org.jetbrains.annotations.NotNull;
-
-public class Foo<T>  {
-    T x;
-
-    public Foo(T x) {
-        this.x = x;
-    }
-
-    public static Number bar() { return null; }
-
-    public static <K> K simpleId(K k) {
-        return k;
-    }
-
-    public T produceT() {
-        return x;
-    }
-
-    @NotNull
-    public T produceNotNullT() {
-        return x;
-    }
-
-    public void consumeT(T x) {}
-}
-
-// FILE: main.kt
-fun <T> bar(n: Number?, d: T, e: T) {
-    val a: Number = <!TYPE_MISMATCH!>Foo.<!TYPE_MISMATCH!>simpleId(n)<!><!>
-    val b: Number? = Foo.simpleId(n)
-    val c = <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Number?")!>Foo.simpleId(n)<!>
-
-    val x4 = Foo(if (true) 10 else null)
-    val x5: Number = <!TYPE_MISMATCH!>x4.produceT()<!>
-    val x6: Number? = x4.produceT()
-    val x7 = <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int?")!>x4.produceT()<!>
-    val x8 = <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>x4.produceNotNullT()<!>
-
-    x4.consumeT(x7)
-
-    val x9: T = Foo.simpleId(d)
-    val x10: T? = Foo.simpleId(d)
-
-    if (e != null) {
-        var x11 = e
-        x11 = Foo.simpleId(d) // assign to definitely not-null T, the lack an error is consistent with old inference
-    }
-
-    var x11 = Foo<T>(null as T).x
-    x11 = Foo.simpleId(d) // assign to flexible T
-
-    var x12 = Foo.bar()
-    x12 = Foo.simpleId(n) // assign to flexible Number
-
-    var x13 = e
-    x13 = Foo.simpleId(d)
-}

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

@@ -14642,11 +14642,6 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/elvisOnUnit.kt");
             }
 
-            @TestMetadata("inferenceFlexibleTToNullable.kt")
-            public void testInferenceFlexibleTToNullable() throws Exception {
-                runTest("compiler/testData/diagnostics/tests/nullableTypes/inferenceFlexibleTToNullable.kt");
-            }
-
             @TestMetadata("nullAssertOnTypeWithNullableUpperBound.kt")
             public void testNullAssertOnTypeWithNullableUpperBound() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/nullAssertOnTypeWithNullableUpperBound.kt");

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

@@ -14637,11 +14637,6 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/elvisOnUnit.kt");
             }
 
-            @TestMetadata("inferenceFlexibleTToNullable.kt")
-            public void testInferenceFlexibleTToNullable() throws Exception {
-                runTest("compiler/testData/diagnostics/tests/nullableTypes/inferenceFlexibleTToNullable.kt");
-            }
-
             @TestMetadata("nullAssertOnTypeWithNullableUpperBound.kt")
             public void testNullAssertOnTypeWithNullableUpperBound() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/nullAssertOnTypeWithNullableUpperBound.kt");

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -18111,11 +18111,6 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/platformTypes"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
-        @TestMetadata("inferenceFlexibleTToNullable.kt")
-        public void testInferenceFlexibleTToNullable() throws Exception {
-            runTest("compiler/testData/codegen/box/platformTypes/inferenceFlexibleTToNullable.kt");
-        }
-
         @TestMetadata("unsafeNullCheck.kt")
         public void testUnsafeNullCheck() throws Exception {
             runTest("compiler/testData/codegen/box/platformTypes/unsafeNullCheck.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -18111,11 +18111,6 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/platformTypes"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
-        @TestMetadata("inferenceFlexibleTToNullable.kt")
-        public void testInferenceFlexibleTToNullable() throws Exception {
-            runTest("compiler/testData/codegen/box/platformTypes/inferenceFlexibleTToNullable.kt");
-        }
-
         @TestMetadata("unsafeNullCheck.kt")
         public void testUnsafeNullCheck() throws Exception {
             runTest("compiler/testData/codegen/box/platformTypes/unsafeNullCheck.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -16595,11 +16595,6 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/platformTypes"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM_IR, true);
         }
 
-        @TestMetadata("inferenceFlexibleTToNullable.kt")
-        public void testInferenceFlexibleTToNullable() throws Exception {
-            runTest("compiler/testData/codegen/box/platformTypes/inferenceFlexibleTToNullable.kt");
-        }
-
         @TestMetadata("unsafeNullCheck.kt")
         public void testUnsafeNullCheck() throws Exception {
             runTest("compiler/testData/codegen/box/platformTypes/unsafeNullCheck.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -16595,11 +16595,6 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/platformTypes"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM_IR, true);
         }
 
-        @TestMetadata("inferenceFlexibleTToNullable.kt")
-        public void testInferenceFlexibleTToNullable() throws Exception {
-            runTest("compiler/testData/codegen/box/platformTypes/inferenceFlexibleTToNullable.kt");
-        }
-
         @TestMetadata("unsafeNullCheck.kt")
         public void testUnsafeNullCheck() throws Exception {
             runTest("compiler/testData/codegen/box/platformTypes/unsafeNullCheck.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -13946,11 +13946,6 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/platformTypes"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JS_IR, true);
         }
 
-        @TestMetadata("inferenceFlexibleTToNullable.kt")
-        public void testInferenceFlexibleTToNullable() throws Exception {
-            runTest("compiler/testData/codegen/box/platformTypes/inferenceFlexibleTToNullable.kt");
-        }
-
         @TestMetadata("compiler/testData/codegen/box/platformTypes/primitives")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -15126,11 +15126,6 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/platformTypes"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JS, true);
         }
 
-        @TestMetadata("inferenceFlexibleTToNullable.kt")
-        public void testInferenceFlexibleTToNullable() throws Exception {
-            runTest("compiler/testData/codegen/box/platformTypes/inferenceFlexibleTToNullable.kt");
-        }
-
         @TestMetadata("compiler/testData/codegen/box/platformTypes/primitives")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)