4 files changed, 46 insertions, 13 deletions
diff --git a/src/compiler/scala/tools/nsc/MainGenericRunner.scala b/src/compiler/scala/tools/nsc/MainGenericRunner.scala
index cef13843dc..cc1139f8a7 100644
--- a/src/compiler/scala/tools/nsc/MainGenericRunner.scala
+++ b/src/compiler/scala/tools/nsc/MainGenericRunner.scala
@@ -7,13 +7,28 @@ package scala.tools.nsc
 
 import java.net.URL
 import scala.tools.util.PathResolver
-
 import io.{ File }
 import util.{ ClassPath, ScalaClassLoader }
 import Properties.{ versionString, copyrightString }
 import interpreter.{ ILoop }
 import GenericRunnerCommand._
 
+object JarRunner extends CommonRunner {
+  def runJar(settings: GenericRunnerSettings, jarPath: String, arguments: Seq[String]): Either[Throwable, Boolean] = {
+    val jar       = new io.Jar(jarPath)
+    val mainClass = jar.mainClass getOrElse sys.error("Cannot find main class for jar: " + jarPath)
+    val jarURLs   = ClassPath expandManifestPath jarPath
+    val urls      = if (jarURLs.isEmpty) File(jarPath).toURL +: settings.classpathURLs else jarURLs
+
+    if (settings.Ylogcp.value) {
+      Console.err.println("Running jar with these URLs as the classpath:")
+      urls foreach println
+    }
+
+    runAndCatch(urls, mainClass, arguments)
+  }
+}
+
 /** An object that runs Scala code.  It has three possible
   * sources for the code to run: pre-compiled code, a script file,
   * or interactive entry.
@@ -56,11 +71,7 @@ class MainGenericRunner {
       case AsScript =>
         ScriptRunner.runScriptAndCatch(settings, thingToRun, command.arguments)
       case AsJar    =>
-        ObjectRunner.runAndCatch(
-          File(thingToRun).toURL +: settings.classpathURLs,
-          new io.Jar(thingToRun).mainClass getOrElse sys.error("Cannot find main class for jar: " + thingToRun),
-          command.arguments
-        )
+        JarRunner.runJar(settings, thingToRun, command.arguments)
       case Error =>
         Right(false)
       case _  =>
diff --git a/src/compiler/scala/tools/nsc/ObjectRunner.scala b/src/compiler/scala/tools/nsc/ObjectRunner.scala
index 6ff0718de7..110de7aad5 100644
--- a/src/compiler/scala/tools/nsc/ObjectRunner.scala
+++ b/src/compiler/scala/tools/nsc/ObjectRunner.scala
@@ -11,12 +11,7 @@ import util.ScalaClassLoader
 import java.lang.reflect.InvocationTargetException
 import util.Exceptional.unwrap
 
-/** An object that runs another object specified by name.
- *
- *  @author  Lex Spoon
- *  @version 1.1, 2007/7/13
- */
-object ObjectRunner {
+trait CommonRunner {
   /** Check whether a class with the specified name
    *  exists on the specified class path. */
   def classExists(urls: List[URL], objectName: String): Boolean =
@@ -41,3 +36,10 @@ object ObjectRunner {
     catch { case e => Left(unwrap(e)) }
   }
 }
+
+/** An object that runs another object specified by name.
+ *
+ *  @author  Lex Spoon
+ *  @version 1.1, 2007/7/13
+ */
+object ObjectRunner extends CommonRunner { }
diff --git a/src/compiler/scala/tools/nsc/io/Jar.scala b/src/compiler/scala/tools/nsc/io/Jar.scala
index ad1598a85d..bbed5a9e20 100644
--- a/src/compiler/scala/tools/nsc/io/Jar.scala
+++ b/src/compiler/scala/tools/nsc/io/Jar.scala
@@ -40,7 +40,15 @@ class Jar(file: File) extends Iterable[JarEntry] {
 
   lazy val jarFile  = new JarFile(file.jfile)
   lazy val manifest = withJarInput(s => Option(s.getManifest))
+
   def mainClass     = manifest map (f => f(Name.MAIN_CLASS))
+  /** The manifest-defined classpath String if available. */
+  def classPathString: Option[String] =
+    for (m <- manifest ; cp <- m.attrs get Name.CLASS_PATH) yield cp
+  def classPathElements: List[String] = classPathString match {
+    case Some(s)  => s split "\\s+" toList
+    case _        => Nil
+  }
 
   def withJarInput[T](f: JarInputStream => T): T = {
     val in = new JarInputStream(file.inputStream())
diff --git a/src/compiler/scala/tools/nsc/util/ClassPath.scala b/src/compiler/scala/tools/nsc/util/ClassPath.scala
index 484f809e6f..622b4db2a2 100644
--- a/src/compiler/scala/tools/nsc/util/ClassPath.scala
+++ b/src/compiler/scala/tools/nsc/util/ClassPath.scala
@@ -13,6 +13,7 @@ import io.{ File, Directory, Path, Jar, AbstractFile, ClassAndJarInfo }
 import scala.tools.util.StringOps.splitWhere
 import Jar.isJarOrZip
 import File.pathSeparator
+import java.net.MalformedURLException
 
 /** <p>
  *    This module provides star expansion of '-classpath' option arguments, behaves the same as
@@ -110,11 +111,22 @@ object ClassPath {
       case dir  => dir filter (_.isClassContainer) map (x => new java.io.File(dir.file, x.name) getPath) toList
     }
   }
+  /** Expand manifest jar classpath entries: these are either urls, or paths
+   *  relative to the location of the jar.
+   */
+  def expandManifestPath(jarPath: String): List[URL] = {
+    val file = File(jarPath)
+    if (!file.isFile) return Nil
+
+    val baseDir = file.parent
+    new Jar(file).classPathElements map (elem =>
+      specToURL(elem) getOrElse (baseDir / elem).toURL
+    )
+  }
 
   /** A useful name filter. */
   def isTraitImplementation(name: String) = name endsWith "$class.class"
 
-  import java.net.MalformedURLException
   def specToURL(spec: String): Option[URL] =
     try Some(new URL(spec))
     catch { case _: MalformedURLException => None }