Two annoying REPL things made less annoying:

 * ctrl-C will no longer kill the repl unless you hit it again
 * ctrl-Z will no longer make the repl useless because of jline

In the service of the first I wrote signal handling code, which we can
put to use in other ways as well. No review.

1 files changed, 8 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/nsc/interpreter/InteractiveReader.scala b/src/compiler/scala/tools/nsc/interpreter/InteractiveReader.scala
index 74b3c6ee48..7e4abd1d76 100644
--- a/src/compiler/scala/tools/nsc/interpreter/InteractiveReader.scala
+++ b/src/compiler/scala/tools/nsc/interpreter/InteractiveReader.scala
@@ -5,19 +5,24 @@
 
 package scala.tools.nsc
 package interpreter
+
+import java.io.IOException
+import java.nio.channels.ClosedByInterruptException
 import scala.util.control.Exception._
+import InteractiveReader._
 
 /** Reads lines from an input stream */
 trait InteractiveReader {
-  import InteractiveReader._
-  import java.io.IOException
 
   protected def readOneLine(prompt: String): String
   val interactive: Boolean
+  def init(): Unit = ()
 
   def readLine(prompt: String): String = {
     def handler: Catcher[String] = {
-      case e: IOException if restartSystemCall(e) => readLine(prompt)
+      case e: ClosedByInterruptException          => error("Reader closed by interrupt.")
+      // Terminal has to be re-initialized after SIGSTP or up arrow etc. stop working.
+      case e: IOException if restartSystemCall(e) => init() ; readLine(prompt)
     }
     catching(handler) { readOneLine(prompt) }
   }
@@ -34,7 +39,6 @@ trait InteractiveReader {
     Properties.isMac && (e.getMessage == msgEINTR)
 }
 
-
 object InteractiveReader {
   val msgEINTR = "Interrupted system call"
   def createDefault(): InteractiveReader = createDefault(null)