Allow console terminal opt out

While running ~scripted that multiple instance of the console terminal
were instantiated which caused problems with reading input. It turned
out that RunFromSourceMain was running in the same jvm process as sbt
and creating a new console terminal in a different classloader. This
both messed up the io of scripted tests when scriptedBufferLog was set
to false but it also made it so that I couldn't exit ~ with <enter>. To
workaround this, I deferred initializaiton of the console terminal to
Terminal.withStreams which is guarded by the sbt.io.virtual system
property.

internal/util-logging/src/main/scala/sbt/internal/util/Terminal.scala

@@ -283,6 +283,8 @@ object Terminal {
   private[sbt] def withStreams[T](isServer: Boolean)(f: => T): T =
     if (System.getProperty("sbt.io.virtual", "true") == "true") {
       hasProgress.set(isServer)
+      consoleTerminalHolder.set(wrap(jline.TerminalFactory.get))
+      activeTerminal.set(consoleTerminalHolder.get)
       try withOut(withIn(f))
       finally {
         jline.TerminalFactory.reset()
@@ -490,7 +492,8 @@ object Terminal {
    * Terminal.console method returns this terminal and the ConsoleChannel delegates its
    * terminal method to it.
    */
-  private[this] val consoleTerminalHolder = new AtomicReference(wrap(jline.TerminalFactory.get))
+  private[this] val consoleTerminalHolder: AtomicReference[Terminal] =
+    new AtomicReference(SimpleTerminal)
 
   /**
    * The terminal that is currently being used by the proxyInputStream and proxyOutputStream.
@@ -915,7 +918,7 @@ object Terminal {
   }
   private lazy val nullWriteableInputStream =
     new WriteableInputStream(nullInputStream, "null-writeable-input-stream")
-  private[sbt] val NullTerminal = new Terminal {
+  private[sbt] class DefaultTerminal extends Terminal {
     override def close(): Unit = {}
     override private[sbt] def progressState: ProgressState = new ProgressState(1)
     override def getBooleanCapability(capability: String, jline3: Boolean): Boolean = false
@@ -926,22 +929,27 @@ object Terminal {
     override def getNumericCapability(capability: String, jline3: Boolean): Integer = null
     override def getStringCapability(capability: String, jline3: Boolean): String = null
     override def getWidth: Int = 0
-    override def inputStream: java.io.InputStream = nullInputStream
+    override def inputStream: InputStream = nullInputStream
     override def isAnsiSupported: Boolean = false
     override def isColorEnabled: Boolean = false
     override def isEchoEnabled: Boolean = false
     override def isSuccessEnabled: Boolean = false
     override def isSupershellEnabled: Boolean = false
-    override def outputStream: java.io.OutputStream = _ => {}
-    override def errorStream: java.io.OutputStream = _ => {}
+    override def outputStream: OutputStream = _ => {}
+    override def errorStream: OutputStream = _ => {}
     override private[sbt] def getAttributes: Map[String, String] = Map.empty
     override private[sbt] def setAttributes(attributes: Map[String, String]): Unit = {}
     override private[sbt] def setSize(width: Int, height: Int): Unit = {}
     override private[sbt] def name: String = "NullTerminal"
-    override private[sbt] val printStream: java.io.PrintStream =
+    override private[sbt] val printStream: PrintStream =
       new PrintStream(outputStream, false)
-    override private[sbt] def withPrintStream[T](f: java.io.PrintStream => T): T = f(printStream)
+    override private[sbt] def withPrintStream[T](f: PrintStream => T): T = f(printStream)
     override private[sbt] def write(bytes: Int*): Unit = {}
     override private[sbt] def withRawOutput[R](f: => R): R = f
   }
+  private[sbt] object NullTerminal extends DefaultTerminal
+  private[sbt] object SimpleTerminal extends DefaultTerminal {
+    override lazy val outputStream: OutputStream = originalOut
+    override lazy val errorStream: OutputStream = originalErr
+  }
 }

sbt/src/test/scala/sbt/RunFromSourceMain.scala

@@ -57,6 +57,7 @@ object RunFromSourceMain {
       )
     case Array(wd, scalaVersion, sbtVersion, classpath, args @ _*) =>
       System.setProperty("jna.nosys", "true")
+      if (args.exists(_.startsWith("<"))) System.setProperty("sbt.io.virtual", "false")
       val context = LoggerContext(useLog4J = SysProp.useLog4J)
       try run(file(wd), scalaVersion, sbtVersion, classpath, args, context)
       finally context.close()