Add NON_VARARG_SPREAD and SPREAD_OF_NULLABLE diagnostics to new inference

compiler/frontend/src/org/jetbrains/kotlin/resolve/PlatformConfiguratorBase.kt

@@ -45,7 +45,7 @@ private val DEFAULT_CALL_CHECKERS = listOf(
     CallableReferenceCompatibilityChecker(), LateinitIntrinsicApplicabilityChecker,
     UnderscoreUsageChecker, AssigningNamedArgumentToVarargChecker(),
     PrimitiveNumericComparisonCallChecker, LambdaWithSuspendModifierCallChecker,
-    UselessElvisCallChecker(), ResultTypeWithNullableOperatorsChecker()
+    UselessElvisCallChecker(), ResultTypeWithNullableOperatorsChecker(), NullableVarargArgumentCallChecker
 )
 private val DEFAULT_TYPE_CHECKERS = emptyList<AdditionalTypeChecker>()
 private val DEFAULT_CLASSIFIER_USAGE_CHECKERS = listOf(

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/NullableVarargArgumentCallChecker.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.resolve.calls.checkers
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.resolve.calls.components.stableType
+import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
+import org.jetbrains.kotlin.resolve.calls.model.VariableAsFunctionResolvedCall
+import org.jetbrains.kotlin.resolve.calls.tower.ExpressionKotlinCallArgumentImpl
+import org.jetbrains.kotlin.resolve.calls.tower.NewResolvedCallImpl
+import org.jetbrains.kotlin.resolve.calls.tower.NewVariableAsFunctionResolvedCallImpl
+import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValueWithSmartCastInfo
+import org.jetbrains.kotlin.types.FlexibleType
+import org.jetbrains.kotlin.types.TypeUtils
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+object NullableVarargArgumentCallChecker : CallChecker {
+    override fun check(resolvedCall: ResolvedCall<*>, reportOn: PsiElement, context: CallCheckerContext) {
+        if (!context.languageVersionSettings.supportsFeature(LanguageFeature.NewInference)) return
+        if (resolvedCall is VariableAsFunctionResolvedCall) {
+            check(resolvedCall.functionCall, reportOn, context)
+            return
+        }
+        if (resolvedCall !is NewResolvedCallImpl<*>) return
+        for (argument in resolvedCall.argumentMappingByOriginal.values) {
+            for (arg in argument.arguments) {
+                if (!arg.isSpread || arg !is ExpressionKotlinCallArgumentImpl) continue
+                val spreadElement = arg.valueArgument.getSpreadElement() ?: continue
+
+                val receiver = arg.receiver.safeAs<ReceiverValueWithSmartCastInfo>() ?: continue
+                val type = receiver.stableType
+                if (type !is FlexibleType && TypeUtils.isNullableType(type)) {
+                    context.trace.report(Errors.SPREAD_OF_NULLABLE.on(spreadElement))
+                }
+            }
+        }
+    }
+}