[NI] Don't consider Nothing-constraint as proper to complete call

Follow-up of 9b3e17f0. There we decided to complete call if a type
 variable from a return type has proper lower constraints, now we refine
 this rule wrt `Nothing`-like constraints to avoid inferring type variables
 to Nothing, which is quite useless

 #KT-30370 Fixed

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

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.resolve.calls.components
 import org.jetbrains.kotlin.resolve.calls.inference.NewConstraintSystem
 import org.jetbrains.kotlin.resolve.calls.inference.components.KotlinConstraintSystemCompleter
 import org.jetbrains.kotlin.resolve.calls.inference.components.KotlinConstraintSystemCompleter.ConstraintSystemCompletionMode
+import org.jetbrains.kotlin.resolve.calls.inference.components.TrivialConstraintTypeInferenceOracle
 import org.jetbrains.kotlin.resolve.calls.inference.model.ConstraintStorage.Empty.hasContradiction
 import org.jetbrains.kotlin.resolve.calls.inference.model.ExpectedTypeConstraintPosition
 import org.jetbrains.kotlin.resolve.calls.model.*
@@ -21,7 +22,8 @@ import org.jetbrains.kotlin.types.typeUtil.isPrimitiveNumberType
 
 class KotlinCallCompleter(
     private val postponedArgumentsAnalyzer: PostponedArgumentsAnalyzer,
-    private val kotlinConstraintSystemCompleter: KotlinConstraintSystemCompleter
+    private val kotlinConstraintSystemCompleter: KotlinConstraintSystemCompleter,
+    private val trivialConstraintTypeInferenceOracle: TrivialConstraintTypeInferenceOracle
 ) {
 
     fun runCompletion(
@@ -172,7 +174,7 @@ class KotlinCallCompleter(
             // This means that there will be no new LOWER constraints =>
             //   it's possible to complete call now if there are proper LOWER constraints
             csBuilder.isTypeVariable(currentReturnType) ->
-                if (hasProperLowerConstraints(currentReturnType))
+                if (hasProperNonTrivialLowerConstraints(currentReturnType))
                     ConstraintSystemCompletionMode.FULL
                 else
                     ConstraintSystemCompletionMode.PARTIAL
@@ -181,13 +183,14 @@ class KotlinCallCompleter(
         }
     }
 
-    private fun KotlinResolutionCandidate.hasProperLowerConstraints(typeVariable: UnwrappedType): Boolean {
+    private fun KotlinResolutionCandidate.hasProperNonTrivialLowerConstraints(typeVariable: UnwrappedType): Boolean {
         assert(csBuilder.isTypeVariable(typeVariable)) { "$typeVariable is not a type variable" }
 
         val constructor = typeVariable.constructor
         val variableWithConstraints = csBuilder.currentStorage().notFixedTypeVariables[constructor] ?: return false
         return variableWithConstraints.constraints.any {
-            it.kind.isLower() && csBuilder.isProperType(it.type) && !it.type.isIntegerValueType()
+            !trivialConstraintTypeInferenceOracle.isTrivialConstraint(it) && !it.type.isIntegerValueType() &&
+                    it.kind.isLower() && csBuilder.isProperType(it.type)
         }
     }
 

compiler/testData/codegen/box/inference/lastExpressionOfLambdaWithNothingConstraint.kt

@@ -0,0 +1,30 @@
+// !LANGUAGE: +NewInference
+// WITH_RUNTIME
+
+inline fun <T> foo(f: () -> T): String {
+    return (f() as? Inv<T>)?.result() ?: "Bad"
+}
+
+class Inv<T> {
+    fun result(): String = "OK"
+}
+
+fun <K> create(): Inv<K> = Inv()
+
+fun test(b: Boolean): String {
+    return foo {
+        if (!b) {
+            return@foo create<String>()
+        }
+
+        if (b) {
+            create()
+        } else {
+            null
+        }
+    }
+}
+
+fun box(): String {
+    return test(true)
+}

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

@@ -11834,6 +11834,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
         public void testKt10822() throws Exception {
             runTest("compiler/testData/codegen/box/inference/kt10822.kt");
         }
+
+        @TestMetadata("lastExpressionOfLambdaWithNothingConstraint.kt")
+        public void testLastExpressionOfLambdaWithNothingConstraint() throws Exception {
+            runTest("compiler/testData/codegen/box/inference/lastExpressionOfLambdaWithNothingConstraint.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/inlineClasses")

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

@@ -11834,6 +11834,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
         public void testKt10822() throws Exception {
             runTest("compiler/testData/codegen/box/inference/kt10822.kt");
         }
+
+        @TestMetadata("lastExpressionOfLambdaWithNothingConstraint.kt")
+        public void testLastExpressionOfLambdaWithNothingConstraint() throws Exception {
+            runTest("compiler/testData/codegen/box/inference/lastExpressionOfLambdaWithNothingConstraint.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/inlineClasses")

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

@@ -11839,6 +11839,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
         public void testKt10822() throws Exception {
             runTest("compiler/testData/codegen/box/inference/kt10822.kt");
         }
+
+        @TestMetadata("lastExpressionOfLambdaWithNothingConstraint.kt")
+        public void testLastExpressionOfLambdaWithNothingConstraint() throws Exception {
+            runTest("compiler/testData/codegen/box/inference/lastExpressionOfLambdaWithNothingConstraint.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/inlineClasses")

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

@@ -9419,6 +9419,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
         public void testKt10822() throws Exception {
             runTest("compiler/testData/codegen/box/inference/kt10822.kt");
         }
+
+        @TestMetadata("lastExpressionOfLambdaWithNothingConstraint.kt")
+        public void testLastExpressionOfLambdaWithNothingConstraint() throws Exception {
+            runTest("compiler/testData/codegen/box/inference/lastExpressionOfLambdaWithNothingConstraint.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/inlineClasses")

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

@@ -10514,6 +10514,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
         public void testKt10822() throws Exception {
             runTest("compiler/testData/codegen/box/inference/kt10822.kt");
         }
+
+        @TestMetadata("lastExpressionOfLambdaWithNothingConstraint.kt")
+        public void testLastExpressionOfLambdaWithNothingConstraint() throws Exception {
+            runTest("compiler/testData/codegen/box/inference/lastExpressionOfLambdaWithNothingConstraint.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/inlineClasses")