fix compilation for Scala 2.13.0-RC1

- BufferWrapper, argument type for patchInPlace updated

Author: Sciss

build.sbt

@@ -10,14 +10,14 @@ scalacOptions in ThisBuild ++= Seq("-deprecation", "-feature")
 
 // Map[JvmMajorVersion, List[(ScalaVersion, UseForPublishing)]]
 scalaVersionsByJvm in ThisBuild := Map(
-   8 -> List("2.11.12", "2.12.8", "2.13.0-M5").map(_ -> true),
-   9 -> List("2.11.12", "2.12.8", "2.13.0-M5").map(_ -> false),
-  10 -> List("2.11.12", "2.12.8", "2.13.0-M5").map(_ -> false),
-  11 -> List("2.11.12", "2.12.8", "2.13.0-M5").map(_ -> false),
-  12 -> List("2.11.12", "2.12.8", "2.13.0-M5").map(_ -> false)
+   8 -> List("2.11.12", "2.12.8", "2.13.0-RC1").map(_ -> true),
+   9 -> List("2.11.12", "2.12.8", "2.13.0-RC1").map(_ -> false),
+  10 -> List("2.11.12", "2.12.8", "2.13.0-RC1").map(_ -> false),
+  11 -> List("2.11.12", "2.12.8", "2.13.0-RC1").map(_ -> false),
+  12 -> List("2.11.12", "2.12.8", "2.13.0-RC1").map(_ -> false)
 )
 
-scalaVersion in ThisBuild := "2.13.0-M5"  // for testing
+scalaVersion in ThisBuild := "2.13.0-RC1"  // for testing
 
 OsgiKeys.exportPackage := Seq(s"scala.swing.*;version=${version.value}")
 
@@ -29,7 +29,7 @@ shellPrompt in ThisBuild := { state => Project.extract(state).currentRef.project
 lazy val swing = project.in(file("."))
   .settings(
     libraryDependencies += {
-      "org.scalatest" %% "scalatest" % "3.0.7" % Test
+      "org.scalatest" %% "scalatest" % "3.0.8-RC2" % Test
     },
     // Adds a `src/main/scala-2.13+` source directory for Scala 2.13 and newer
     // and  a `src/main/scala-2.13-` source directory for Scala version older than 2.13

src/main/scala-2.13+/scala/swing/BufferWrapper.scala

@@ -48,13 +48,11 @@ abstract class BufferWrapper[A] extends mutable.Buffer[A] {
     }
   }
 
-  override def patchInPlace(from: Int, patch: scala.collection.Seq[A], replaced: Int): this.type = {
+  override def patchInPlace(from: Int, patch: MoreElem[A], replaced: Int): this.type = {
     if (replaced > 0) {
       remove(from, replaced)
     }
-    if (patch.nonEmpty) {
-      insertAll(from, patch)
-    }
+    insertAll(from, patch)
     this
   }
 }