FIR IDE: ignore smartcast if it's unstable in HL API

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirSmartcastProvider.kt

@@ -10,11 +10,13 @@ import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.types.ConeKotlinType
 import org.jetbrains.kotlin.fir.types.coneTypeSafe
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.getOrBuildFirSafe
-import org.jetbrains.kotlin.idea.frontend.api.*
+import org.jetbrains.kotlin.idea.frontend.api.ImplicitReceiverSmartCast
+import org.jetbrains.kotlin.idea.frontend.api.ImplicitReceiverSmartcastKind
 import org.jetbrains.kotlin.idea.frontend.api.components.KtSmartCastProvider
 import org.jetbrains.kotlin.idea.frontend.api.fir.KtFirAnalysisSession
 import org.jetbrains.kotlin.idea.frontend.api.tokens.ValidityToken
 import org.jetbrains.kotlin.idea.frontend.api.types.KtType
+import org.jetbrains.kotlin.idea.frontend.api.withValidityAssertion
 import org.jetbrains.kotlin.psi.KtExpression
 
 internal class KtFirSmartcastProvider(
@@ -23,6 +25,7 @@ internal class KtFirSmartcastProvider(
 ) : KtSmartCastProvider(), KtFirAnalysisSessionComponent {
     override fun getSmartCastedToType(expression: KtExpression): KtType? = withValidityAssertion {
         expression.getOrBuildFirSafe<FirExpressionWithSmartcast>(analysisSession.firResolveState)
+            ?.takeIf { it.isStable }
             ?.typeRef
             ?.coneTypeSafe<ConeKotlinType>()
             ?.asKtType()
@@ -32,17 +35,19 @@ internal class KtFirSmartcastProvider(
     override fun getImplicitReceiverSmartCast(expression: KtExpression): Collection<ImplicitReceiverSmartCast> = withValidityAssertion {
         val qualifiedExpression =
             expression.getOrBuildFirSafe<FirQualifiedAccessExpression>(analysisSession.firResolveState) ?: return emptyList()
-        if (qualifiedExpression.dispatchReceiver !is FirExpressionWithSmartcast
+        val dispatchReceiver = qualifiedExpression.dispatchReceiver
-            && qualifiedExpression.extensionReceiver !is FirExpressionWithSmartcast
+        val extensionReceiver = qualifiedExpression.extensionReceiver
+        if ((dispatchReceiver !is FirExpressionWithSmartcast || !dispatchReceiver.isStable) &&
+            (extensionReceiver !is FirExpressionWithSmartcast || !extensionReceiver.isStable)
         ) return emptyList()
         buildList {
-            (qualifiedExpression.dispatchReceiver as? FirExpressionWithSmartcast)?.let { smartCasted ->
+            (dispatchReceiver as? FirExpressionWithSmartcast)?.takeIf { it.isStable }?.let { smartCasted ->
                 ImplicitReceiverSmartCast(
                     smartCasted.typeRef.coneTypeSafe<ConeKotlinType>()?.asKtType() ?: return@let null,
                     ImplicitReceiverSmartcastKind.DISPATCH
                 )
             }?.let(::add)
-            (qualifiedExpression.extensionReceiver as? FirExpressionWithSmartcast)?.let { smartCasted ->
+            (extensionReceiver as? FirExpressionWithSmartcast)?.takeIf { it.isStable }?.let { smartCasted ->
                 ImplicitReceiverSmartCast(
                     smartCasted.typeRef.coneTypeSafe<ConeKotlinType>()?.asKtType() ?: return@let null,
                     ImplicitReceiverSmartcastKind.EXTENSION