From a03f795a4d1a89c5bd324b2c923be12940789782 Mon Sep 17 00:00:00 2001
From: Allan Renucci <allan.renucci@gmail.com>
Date: Tue, 10 Oct 2017 11:39:01 +0200
Subject: [PATCH 1/2] Fix #3279

When using the repl through "sbt console", we used to use the class
loader sbt give us. But we need a class loader that has the output
directory of the compiler on the classpath
---
 compiler/src/dotty/tools/repl/Rendering.scala | 30 +++++++++----------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/compiler/src/dotty/tools/repl/Rendering.scala b/compiler/src/dotty/tools/repl/Rendering.scala
index 1f7167845b4e..15125320ef1e 100644
--- a/compiler/src/dotty/tools/repl/Rendering.scala
+++ b/compiler/src/dotty/tools/repl/Rendering.scala
@@ -21,24 +21,24 @@ import dotc.core.StdNames.str
  *       `Rendering` is no longer valid.
  */
 private[repl] class Rendering(compiler: ReplCompiler,
-                              private var currentClassLoader: Option[ClassLoader] = None) {
+                              parentClassLoader: Option[ClassLoader] = None) {
 
-  private def classLoader()(implicit ctx: Context) =
-    currentClassLoader.getOrElse {
-      import java.net.{URL, URLClassLoader}
+  private[this] var myClassLoader: ClassLoader = _
 
-      /** the compiler's classpath, as URL's */
-      val compilerClasspath: Seq[URL] = ctx.platform.classPath(ctx).asURLs
+  /** Class loader used to load compiled code */
+  private[this] def classLoader()(implicit ctx: Context) =
+    if (myClassLoader != null) myClassLoader
+    else {
+      val parent = parentClassLoader.getOrElse {
+        // the compiler's classpath, as URL's
+        val compilerClasspath = ctx.platform.classPath(ctx).asURLs
+        new java.net.URLClassLoader(compilerClasspath.toArray, classOf[ReplDriver].getClassLoader)
+      }
 
-      def parent = new URLClassLoader(compilerClasspath.toArray,
-                                      classOf[ReplDriver].getClassLoader)
-
-      val newClsLoader = new AbstractFileClassLoader(compiler.directory,
-                                  currentClassLoader.getOrElse(parent))
-
-      Thread.currentThread.setContextClassLoader(newClsLoader)
-      currentClassLoader = Some(newClsLoader)
-      newClsLoader
+      myClassLoader = new AbstractFileClassLoader(compiler.directory, parent)
+      // Set the current Java "context" class loader to this rendering class loader
+      Thread.currentThread.setContextClassLoader(myClassLoader)
+      myClassLoader
     }
 
   /** Load the value of the symbol using reflection

From 061fdb1a57a6543412b404ff77527bcccc2ee39e Mon Sep 17 00:00:00 2001
From: Allan Renucci <allan.renucci@gmail.com>
Date: Tue, 10 Oct 2017 13:18:31 +0200
Subject: [PATCH 2/2] Add test case

We need to support "initialCommands" in the repl, otherwise this
tests nothing...
---
 sbt-dotty/sbt-test/sbt-dotty/example-project/test | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sbt-dotty/sbt-test/sbt-dotty/example-project/test b/sbt-dotty/sbt-test/sbt-dotty/example-project/test
index 62ea636c177f..885d666a4c01 100644
--- a/sbt-dotty/sbt-test/sbt-dotty/example-project/test
+++ b/sbt-dotty/sbt-test/sbt-dotty/example-project/test
@@ -1 +1,3 @@
 > run
+> 'set initialCommands := "1 + 1" '
+> console