[FE 1.0] Don't report CAST_NEVER_SUCCEEDS on stub types

^KT-49829 Fixed

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -13944,6 +13944,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                     runTest("compiler/testData/diagnostics/tests/inference/builderInference/kt47744.kt");
                 }
 
+                @Test
+                @TestMetadata("kt49829.kt")
+                public void testKt49829() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/builderInference/kt49829.kt");
+                }
+
                 @Test
                 @TestMetadata("labaledCall.kt")
                 public void testLabaledCall() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -13944,6 +13944,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                     runTest("compiler/testData/diagnostics/tests/inference/builderInference/kt47744.kt");
                 }
 
+                @Test
+                @TestMetadata("kt49829.kt")
+                public void testKt49829() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/builderInference/kt49829.kt");
+                }
+
                 @Test
                 @TestMetadata("labaledCall.kt")
                 public void testLabaledCall() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java

@@ -13944,6 +13944,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                     runTest("compiler/testData/diagnostics/tests/inference/builderInference/kt47744.kt");
                 }
 
+                @Test
+                @TestMetadata("kt49829.kt")
+                public void testKt49829() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/builderInference/kt49829.kt");
+                }
+
                 @Test
                 @TestMetadata("labaledCall.kt")
                 public void testLabaledCall() throws Exception {

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java

@@ -76,6 +76,7 @@ import org.jetbrains.kotlin.types.checker.KotlinTypeChecker;
 import org.jetbrains.kotlin.types.expressions.ControlStructureTypingUtils.ResolveConstruct;
 import org.jetbrains.kotlin.types.expressions.typeInfoFactory.TypeInfoFactoryKt;
 import org.jetbrains.kotlin.types.expressions.unqualifiedSuper.UnqualifiedSuperKt;
+import org.jetbrains.kotlin.types.typeUtil.TypeUtilsKt;
 import org.jetbrains.kotlin.util.OperatorNameConventions;
 
 import java.util.Collection;
@@ -372,7 +373,7 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
             return;
         }
 
-        if (!CastDiagnosticsUtil.isCastPossible(actualType, targetType, components.platformToKotlinClassMapper)) {
+        if (!CastDiagnosticsUtil.isCastPossible(actualType, targetType, components.platformToKotlinClassMapper) && !TypeUtilsKt.isStubType(actualType)) {
             context.trace.report(CAST_NEVER_SUCCEEDS.on(expression.getOperationReference()));
             return;
         }

compiler/testData/diagnostics/tests/inference/builderInference/kt49829.fir.kt

@@ -0,0 +1,12 @@
+// WITH_STDLIB
+// For FIR: see KT-50293
+
+fun main() {
+    val list = buildList {
+        add("one")
+        add("two")
+
+        val secondParameter = get(1)
+        println(secondParameter <!USELESS_CAST!>as String<!>) // WARNING: [CAST_NEVER_SUCCEEDS] This cast can never succeed
+    }
+}

compiler/testData/diagnostics/tests/inference/builderInference/kt49829.kt

@@ -0,0 +1,12 @@
+// WITH_STDLIB
+// For FIR: see KT-50293
+
+fun main() {
+    val list = buildList {
+        add("one")
+        add("two")
+
+        val secondParameter = get(1)
+        println(secondParameter as String) // WARNING: [CAST_NEVER_SUCCEEDS] This cast can never succeed
+    }
+}

compiler/testData/diagnostics/tests/inference/builderInference/kt49829.txt

@@ -0,0 +1,3 @@
+package
+
+public fun main(): kotlin.Unit

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -13950,6 +13950,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                     runTest("compiler/testData/diagnostics/tests/inference/builderInference/kt47744.kt");
                 }
 
+                @Test
+                @TestMetadata("kt49829.kt")
+                public void testKt49829() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/builderInference/kt49829.kt");
+                }
+
                 @Test
                 @TestMetadata("labaledCall.kt")
                 public void testLabaledCall() throws Exception {

core/descriptors/src/org/jetbrains/kotlin/types/TypeUtils.kt

@@ -24,10 +24,8 @@ import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.calls.inference.isCaptured
 import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
 import org.jetbrains.kotlin.types.*
-import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
-import org.jetbrains.kotlin.types.checker.NewCapturedType
-import org.jetbrains.kotlin.types.checker.NewCapturedTypeConstructor
-import org.jetbrains.kotlin.types.checker.intersectTypes
+import org.jetbrains.kotlin.types.checker.*
+import org.jetbrains.kotlin.types.model.SimpleTypeMarker
 import org.jetbrains.kotlin.types.model.TypeArgumentMarker
 import org.jetbrains.kotlin.types.model.TypeVariableTypeConstructorMarker
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
@@ -391,3 +389,13 @@ private fun NewCapturedType.unCaptureTopLevelType(): UnwrappedType {
 
 fun KotlinType?.shouldBeUpdated() =
     this == null || contains { it is StubTypeForBuilderInference || it.constructor is TypeVariableTypeConstructorMarker || it.isError }
+
+fun KotlinType.isStubType() = this is AbstractStubType || isDefNotNullStubType<AbstractStubType>()
+
+fun KotlinType.isStubTypeForVariableInSubtyping(): Boolean =
+    this is StubTypeForTypeVariablesInSubtyping || isDefNotNullStubType<StubTypeForTypeVariablesInSubtyping>()
+
+fun KotlinType.isStubTypeForBuilderInference(): Boolean =
+    this is StubTypeForBuilderInference || isDefNotNullStubType<StubTypeForBuilderInference>()
+
+private inline fun <reified S : AbstractStubType> KotlinType.isDefNotNullStubType() = this is DefinitelyNotNullType && this.original is S

core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt

@@ -30,6 +30,9 @@ import org.jetbrains.kotlin.utils.addIfNotNull
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 import org.jetbrains.kotlin.types.typeUtil.isSignedOrUnsignedNumberType as classicIsSignedOrUnsignedNumberType
+import org.jetbrains.kotlin.types.typeUtil.isStubTypeForVariableInSubtyping as isSimpleTypeStubTypeForVariableInSubtyping
+import org.jetbrains.kotlin.types.typeUtil.isStubTypeForBuilderInference as isSimpleTypeStubTypeForBuilderInference
+import org.jetbrains.kotlin.types.typeUtil.isStubType as isSimpleTypeStubType
 
 interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSystemCommonBackendContext {
     override fun TypeConstructorMarker.isDenotable(): Boolean {
@@ -86,20 +89,17 @@ interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSy
 
     override fun SimpleTypeMarker.isStubType(): Boolean {
         require(this is SimpleType, this::errorMessage)
-        return this is AbstractStubType || isDefNotNullStubType<AbstractStubType>()
+        return this.isSimpleTypeStubType()
     }
 
-    private inline fun <reified S : AbstractStubType> SimpleTypeMarker.isDefNotNullStubType() =
-        this is DefinitelyNotNullType && this.original is S
-
     override fun SimpleTypeMarker.isStubTypeForVariableInSubtyping(): Boolean {
         require(this is SimpleType, this::errorMessage)
-        return this is StubTypeForTypeVariablesInSubtyping || isDefNotNullStubType<StubTypeForTypeVariablesInSubtyping>()
+        return this.isSimpleTypeStubTypeForVariableInSubtyping()
     }
 
     override fun SimpleTypeMarker.isStubTypeForBuilderInference(): Boolean {
         require(this is SimpleType, this::errorMessage)
-        return this is StubTypeForBuilderInference || isDefNotNullStubType<StubTypeForBuilderInference>()
+        return this.isSimpleTypeStubTypeForBuilderInference()
     }
 
     override fun TypeConstructorMarker.unwrapStubTypeVariableConstructor(): TypeConstructorMarker {