Fix SAM conversion when lambda is the last expression of another lambda

#KT-39691 Fixed

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

@@ -19776,6 +19776,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
             runTest("compiler/testData/diagnostics/tests/samConversions/checkSamConversionsAreDisabledByDefault.kt");
         }
 
+        @TestMetadata("conversionOnLambdaAsLastExpression.kt")
+        public void testConversionOnLambdaAsLastExpression() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/samConversions/conversionOnLambdaAsLastExpression.kt");
+        }
+
         @TestMetadata("DisabledForKTSimple.kt")
         public void testDisabledForKTSimple() throws Exception {
             runTest("compiler/testData/diagnostics/tests/samConversions/DisabledForKTSimple.kt");

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

@@ -45,12 +45,29 @@ object SamTypeConversions : ParameterTypeConversion {
 
     override fun conversionIsNeededBeforeSubtypingCheck(argument: KotlinCallArgument): Boolean {
         return when (argument) {
+            is SubKotlinCallArgument -> {
+                val stableType = argument.receiver.stableType
+                hasNonAnalyzedLambdaAsReturnType(argument.callResult.subResolvedAtoms, stableType)
+            }
             is SimpleKotlinCallArgument -> argument.receiver.stableType.isFunctionType
             is LambdaKotlinCallArgument, is CallableReferenceKotlinCallArgument -> true
             else -> false
         }
     }
 
+    private fun hasNonAnalyzedLambdaAsReturnType(subResolvedAtoms: List<ResolvedAtom>?, type: UnwrappedType): Boolean {
+        subResolvedAtoms?.forEach {
+            if (it is LambdaWithTypeVariableAsExpectedTypeAtom) {
+                if (it.expectedType.constructor == type.constructor) return true
+            }
+
+            val hasNonAnalyzedLambda = hasNonAnalyzedLambdaAsReturnType(it.subResolvedAtoms, type)
+            if (hasNonAnalyzedLambda) return true
+        }
+
+        return false
+    }
+
     override fun conversionIsNeededAfterSubtypingCheck(argument: KotlinCallArgument): Boolean {
         return argument is SimpleKotlinCallArgument && argument.receiver.stableType.isFunctionTypeOrSubtype
     }

compiler/testData/diagnostics/tests/samConversions/conversionOnLambdaAsLastExpression.kt

@@ -0,0 +1,20 @@
+// FIR_IDENTICAL
+
+// FILE: C.java
+
+public interface C { void on(String s); }
+
+// FILE: A.java
+
+public class A { void add(C c) {} }
+
+// FILE: test.kt
+
+class B : A() {
+    fun test(x: Any?) {
+        add(foo { { _ : String -> Unit } })
+        add(x?.let { { _ : String -> Unit } })
+    }
+}
+
+fun <T> foo(f: () -> T): T = f()

compiler/testData/diagnostics/tests/samConversions/conversionOnLambdaAsLastExpression.txt

@@ -0,0 +1,27 @@
+package
+
+public fun </*0*/ T> foo(/*0*/ f: () -> T): T
+
+public open class A {
+    public constructor A()
+    public/*package*/ open fun add(/*0*/ c: C!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class B : A {
+    public constructor B()
+    public/*package*/ open override /*1*/ /*fake_override*/ fun add(/*0*/ c: C!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final fun test(/*0*/ x: kotlin.Any?): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface C {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun on(/*0*/ s: kotlin.String!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

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

@@ -19788,6 +19788,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTestWithFirVali
                 runTest("compiler/testData/diagnostics/tests/samConversions/checkSamConversionsAreDisabledByDefault.kt");
             }
 
+            @TestMetadata("conversionOnLambdaAsLastExpression.kt")
+            public void testConversionOnLambdaAsLastExpression() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/samConversions/conversionOnLambdaAsLastExpression.kt");
+            }
+
             @TestMetadata("DisabledForKTSimple.kt")
             public void testDisabledForKTSimple() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/samConversions/DisabledForKTSimple.kt");

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

@@ -19778,6 +19778,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 runTest("compiler/testData/diagnostics/tests/samConversions/checkSamConversionsAreDisabledByDefault.kt");
             }
 
+            @TestMetadata("conversionOnLambdaAsLastExpression.kt")
+            public void testConversionOnLambdaAsLastExpression() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/samConversions/conversionOnLambdaAsLastExpression.kt");
+            }
+
             @TestMetadata("DisabledForKTSimple.kt")
             public void testDisabledForKTSimple() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/samConversions/DisabledForKTSimple.kt");