Fix default methods visibility

compiler/ir/backend.common/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -30,6 +30,7 @@ import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.resolve.calls.components.isVararg
 import org.jetbrains.kotlin.resolve.source.PsiSourceElement
 import org.jetbrains.kotlin.types.KotlinType
 
@@ -118,8 +119,8 @@ fun IrMemberAccessExpression.addArguments(args: List<Pair<ParameterDescriptor, I
 
 fun IrExpression.isNullConst() = this is IrConst<*> && this.kind == IrConstKind.Null
 
-fun IrCall.usesDefaultArguments(): Boolean =
-        this.descriptor.valueParameters.any { this.getValueArgument(it) == null }
+fun IrMemberAccessExpression.usesDefaultArguments(): Boolean =
+        this.descriptor.valueParameters.any { this.getValueArgument(it) == null && !it.isVararg}
 
 fun IrFunction.createParameterDeclarations() {
     fun ParameterDescriptor.irValueParameter() = IrValueParameterImpl(

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/FunctionCodegen.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.backend.jvm.codegen
 
+import org.jetbrains.kotlin.backend.common.lower.DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER
 import org.jetbrains.kotlin.backend.jvm.descriptors.JvmDescriptorWithExtraFlags
 import org.jetbrains.kotlin.backend.jvm.lower.InitializersLowering
 import org.jetbrains.kotlin.codegen.*
@@ -57,15 +58,7 @@ open class FunctionCodegen(private val irFunction: IrFunction, private val class
         val frameMap = createFrameMapWithReceivers(classCodegen.state, descriptor, signature, isStatic)
 
 
-        var flags = AsmUtil.getMethodAsmFlags(descriptor, OwnerKind.IMPLEMENTATION, state).or(if (isStatic) Opcodes.ACC_STATIC else 0).xor(
-                if (DescriptorUtils.isAnnotationClass(descriptor.containingDeclaration)) Opcodes.ACC_FINAL else 0/*TODO*/
-        ).or(if (descriptor is JvmDescriptorWithExtraFlags) descriptor.extraFlags else 0)
-
-        val interfaceClInit = JvmCodegenUtil.isJvmInterface(classCodegen.descriptor) && InitializersLowering.clinitName == descriptor.name
-        if (interfaceClInit) {
-            //reset abstract flag
-            flags = flags.xor(Opcodes.ACC_ABSTRACT)
-        }
+        val flags = calculateMethodFlags(isStatic)
         val methodVisitor = createMethod(flags, signature)
 
         FunctionCodegen.generateMethodAnnotations(descriptor, signature.asmMethod, methodVisitor, classCodegen, state.typeMapper)
@@ -80,6 +73,23 @@ open class FunctionCodegen(private val irFunction: IrFunction, private val class
         ExpressionCodegen(irFunction, frameMap, InstructionAdapter(methodVisitor), classCodegen).generate()
     }
 
+    private fun calculateMethodFlags(isStatic: Boolean): Int {
+        var flags = AsmUtil.getMethodAsmFlags(descriptor, OwnerKind.IMPLEMENTATION, state).or(if (isStatic) Opcodes.ACC_STATIC else 0).xor(
+                if (DescriptorUtils.isAnnotationClass(descriptor.containingDeclaration)) Opcodes.ACC_FINAL else 0/*TODO*/
+        ).or(if (descriptor is JvmDescriptorWithExtraFlags) descriptor.extraFlags else 0)
+
+        if (irFunction.origin == DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER) {
+            flags = flags.xor(AsmUtil.getVisibilityAccessFlag(descriptor)).or(Opcodes.ACC_PUBLIC)
+        }
+
+        val interfaceClInit = JvmCodegenUtil.isJvmInterface(classCodegen.descriptor) && InitializersLowering.clinitName == descriptor.name
+        if (interfaceClInit) {
+            //reset abstract flag
+            flags = flags.xor(Opcodes.ACC_ABSTRACT)
+        }
+        return flags
+    }
+
     open protected fun createMethod(flags: Int, signature: JvmMethodGenericSignature): MethodVisitor {
         return classCodegen.visitor.newMethod(irFunction.OtherOrigin,
                                               flags,

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/SyntheticAccessorLowering.kt

@@ -42,6 +42,7 @@ import org.jetbrains.kotlin.ir.expressions.IrMemberAccessExpression
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
 import org.jetbrains.kotlin.ir.symbols.impl.createFunctionSymbol
+import org.jetbrains.kotlin.ir.util.usesDefaultArguments
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformer
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.DescriptorUtils
@@ -156,7 +157,7 @@ class SyntheticAccessorLowering(val context: JvmBackendContext) : FileLoweringPa
         fun createSyntheticAccessorCallForFunction(superResult: IrElement, expression: IrMemberAccessExpression, codegenContext: CodegenContext<*>?, context: JvmBackendContext): IrElement {
 
             val descriptor = expression.descriptor
-            if (descriptor is FunctionDescriptor) {
+            if (descriptor is FunctionDescriptor && !expression.usesDefaultArguments()) {
                 val directAccessor = codegenContext!!.accessibleDescriptor(JvmCodegenUtil.getDirectMember(descriptor), (expression as? IrCall)?.superQualifier)
                 val accessor = Companion.actualAccessor(descriptor, directAccessor)