KT-51284 Fix SAM conversion for methods with context receivers

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -17456,6 +17456,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                 runTest("compiler/testData/codegen/box/extensionFunctions/contextReceivers/iteratorOperator.kt");
             }
 
+            @Test
+            @TestMetadata("kt51284.kt")
+            public void testKt51284() throws Exception {
+                runTest("compiler/testData/codegen/box/extensionFunctions/contextReceivers/kt51284.kt");
+            }
+
             @Test
             @TestMetadata("kt51863.kt")
             public void testKt51863() throws Exception {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/SamResolution.kt

@@ -387,12 +387,15 @@ private fun FirSimpleFunction.getFunctionTypeForAbstractMethod(): ConeLookupTagB
     val parameterTypes = valueParameters.map {
         it.returnTypeRef.coneTypeSafe<ConeKotlinType>() ?: ConeErrorType(ConeIntermediateDiagnostic("No type for parameter $it"))
     }
-
+    val contextReceiversTypes = contextReceivers.map {
+        it.typeRef.coneTypeSafe<ConeKotlinType>() ?: ConeErrorType(ConeIntermediateDiagnostic("No type for context receiver $it"))
+    }
     return createFunctionalType(
         parameterTypes,
         receiverType = receiverParameter?.typeRef?.coneType,
         rawReturnType = returnTypeRef.coneType,
-        isSuspend = this.isSuspend
+        isSuspend = this.isSuspend,
+        contextReceivers = contextReceiversTypes
     )
 }
 

compiler/testData/codegen/box/extensionFunctions/contextReceivers/kt51284.kt

@@ -0,0 +1,23 @@
+// !LANGUAGE: +ContextReceivers
+// TARGET_BACKEND: JVM_IR
+
+class Context
+
+fun interface SAM {
+    context(Context)
+    fun foo(x: Int): Int
+}
+
+fun box(): String {
+    val sam1 = SAM { x -> x + 1 }
+    val sam2 = SAM { 2 }
+    val sam3 = SAM { it + 1 }
+
+    with(Context()) {
+        sam1.foo(0)
+        sam2.foo(0)
+        sam3.foo(0)
+    }
+
+    return "OK"
+}

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

@@ -17456,6 +17456,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/extensionFunctions/contextReceivers/iteratorOperator.kt");
             }
 
+            @Test
+            @TestMetadata("kt51284.kt")
+            public void testKt51284() throws Exception {
+                runTest("compiler/testData/codegen/box/extensionFunctions/contextReceivers/kt51284.kt");
+            }
+
             @Test
             @TestMetadata("kt51863.kt")
             public void testKt51863() throws Exception {

core/descriptors/src/org/jetbrains/kotlin/resolve/sam/SamConversionResolverImpl.kt

@@ -77,14 +77,14 @@ fun getFunctionTypeForAbstractMethod(
     val parameterNames = ArrayList<Name>(valueParameters.size)
 
     val contextReceiversTypes = function.contextReceiverParameters.map { it.type }
-    var startIndex = contextReceiversTypes.size
+    var startIndex = 0
     var receiverType: KotlinType? = null
     val extensionReceiver = function.extensionReceiverParameter
     if (extensionReceiver != null) {
         receiverType = extensionReceiver.type
     } else if (shouldConvertFirstParameterToDescriptor && function.valueParameters.isNotEmpty()) {
         receiverType = valueParameters[0].type
-        startIndex += 1
+        startIndex = 1
     }
 
     for (i in startIndex until valueParameters.size) {