don't put scala-library.jar on the boot classpath unless it is on the classpath

compile/AnalyzingCompiler.scala

@@ -58,7 +58,7 @@ final class AnalyzingCompiler(val scalaInstance: xsbti.compile.ScalaInstance, va
 	{
 		val arguments = new CompilerArguments(scalaInstance, cp)
 		val classpathString = CompilerArguments.absString(arguments.finishClasspath(classpath))
-		val bootClasspath = if(cp.autoBoot) arguments.createBootClasspath else ""
+		val bootClasspath = if(cp.autoBoot) arguments.createBootClasspathFor(classpath) else ""
 		val (names, values) = bindings.unzip
 		call("xsbt.ConsoleInterface", "run", log)(
 			classOf[Array[String]], classOf[String], classOf[String], classOf[String], classOf[String], classOf[ClassLoader], classOf[Array[String]], classOf[Array[Any]], classOf[xLogger])(

compile/CompilerArguments.scala

@@ -25,7 +25,7 @@ final class CompilerArguments(scalaInstance: xsbti.compile.ScalaInstance, cp: xs
 		val dummy = "dummy_" + Integer.toHexString(util.Random.nextInt)
 		val classpathOption = Seq("-classpath", if(cpWithCompiler.isEmpty) dummy else absString(cpWithCompiler))
 		val outputOption = Seq("-d", outputDirectory.getAbsolutePath)
-		options ++ outputOption ++ bootClasspathOption ++ classpathOption ++ abs(sources)
+		options ++ outputOption ++ bootClasspathOption(hasLibrary(classpath)) ++ classpathOption ++ abs(sources)
 	}
 	def finishClasspath(classpath: Seq[File]): Seq[File] =
 		filterLibrary(classpath) ++ include(cp.compiler, scalaInstance.compilerJar) ++ include(cp.extra, scalaInstance.otherJars : _*)
@@ -36,11 +36,13 @@ final class CompilerArguments(scalaInstance: xsbti.compile.ScalaInstance, cp: xs
 		val scalaHome = System.getProperty("scala.home")
 		assert((scalaHome eq null) || scalaHome.isEmpty, "'scala.home' should not be set (was " + scalaHome + ")")
 	}
-	/** Add the correct Scala library jar to the boot classpath.*/
+	def createBootClasspathFor(classpath: Seq[File]) = createBootClasspath(hasLibrary(classpath))
-	def createBootClasspath =
+
+	/** Add the correct Scala library jar to the boot classpath if `addLibrary` is true.*/
+	def createBootClasspath(addLibrary: Boolean) =
 	{
 		val originalBoot = System.getProperty("sun.boot.class.path", "")
-		if(cp.bootLibrary)
+		if(addLibrary)
 		{
 			val newBootPrefix = if(originalBoot.isEmpty) "" else originalBoot + File.pathSeparator
 			newBootPrefix + scalaInstance.libraryJar.getAbsolutePath
@@ -48,10 +50,15 @@ final class CompilerArguments(scalaInstance: xsbti.compile.ScalaInstance, cp: xs
 		else
 			originalBoot
 	}
-	def filterLibrary(classpath: Seq[File]) =
+	def filterLibrary(classpath: Seq[File]) = if(cp.filterLibrary) classpath filterNot isScalaLibrary else classpath
-		if(cp.filterLibrary) classpath.filterNot(_.getName contains ArtifactInfo.ScalaLibraryID) else classpath
+	def hasLibrary(classpath: Seq[File]) = classpath exists isScalaLibrary
-	def bootClasspathOption = if(cp.autoBoot) Seq(BootClasspathOption, createBootClasspath) else Nil
+	private[this] val isScalaLibrary: File => Boolean = file => {
-	def bootClasspath = if(cp.autoBoot) IO.parseClasspath(createBootClasspath) else Nil
+		val name = file.getName
+		(name contains ArtifactInfo.ScalaLibraryID) || file.getName == scalaInstance.libraryJar.getName
+	}
+	def bootClasspathOption(addLibrary: Boolean) = if(cp.autoBoot) Seq(BootClasspathOption, createBootClasspath(addLibrary)) else Nil
+	def bootClasspath(addLibrary: Boolean) = if(cp.autoBoot) IO.parseClasspath(createBootClasspath(addLibrary)) else Nil
+	def bootClasspathFor(classpath: Seq[File]) = bootClasspath(hasLibrary(classpath))
 }
 object CompilerArguments
 {

compile/integration/AggressiveCompile.scala

@@ -32,7 +32,7 @@ class AggressiveCompile(cacheFile: File)
 	}
 
 	def withBootclasspath(args: CompilerArguments, classpath: Seq[File]): Seq[File] =
-		args.bootClasspath ++ args.finishClasspath(classpath)
+		args.bootClasspathFor(classpath) ++ args.finishClasspath(classpath)
 
 	def compile1(sources: Seq[File], classpath: Seq[File], setup: CompileSetup, store: AnalysisStore, analysis: File => Option[Analysis], definesClass: DefinesClass, compiler: AnalyzingCompiler, javac: xsbti.compile.JavaCompiler, maxErrors: Int, skip: Boolean, cache: GlobalsCache)(implicit log: Logger): Analysis =
 	{

compile/src/test/scala/CompileTest.scala

@@ -70,7 +70,7 @@ object CompileTest extends Specification
 			val noCompiler = compiler(true, false)
 			val fullExplicit = compiler(false, false)
 			
-			val fullBoot = "-bootclasspath" :: fullExplicit.compilerArguments.createBootClasspath :: Nil
+			val fullBoot = "-bootclasspath" :: fullExplicit.compilerArguments.createBootClasspath(true) :: Nil
 			val withCompiler = noCompiler.scalaInstance.compilerJar :: Nil
 			val withLibrary = noCompiler.scalaInstance.libraryJar :: Nil
 			val withLibraryCompiler = withLibrary ++ withCompiler