From 9253fc337e4f36029f90f31b1b4e116d0a77ae05 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Wed, 27 May 2015 00:52:02 +0200
Subject: [PATCH] cmd/geth: exit the console cleanly when interrupted

This fix applies mostly to unsupported terminals that do not trigger the
special interrupt handling in liner. Supported terminals were covered
because liner.Prompt returns an error if Ctrl-C is pressed.
---
 cmd/geth/js.go | 68 ++++++++++++++++++++++++++++++++++----------------
 1 file changed, 46 insertions(+), 22 deletions(-)

diff --git a/cmd/geth/js.go b/cmd/geth/js.go
index 0fb234d455..706bc6554f 100644
--- a/cmd/geth/js.go
+++ b/cmd/geth/js.go
@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"math/big"
 	"os"
+	"os/signal"
 	"path/filepath"
 	"strings"
 
@@ -47,7 +48,8 @@ type dumbterm struct{ r *bufio.Reader }
 
 func (r dumbterm) Prompt(p string) (string, error) {
 	fmt.Print(p)
-	return r.r.ReadString('\n')
+	line, err := r.r.ReadString('\n')
+	return strings.TrimSuffix(line, "\n"), err
 }
 
 func (r dumbterm) PasswordPrompt(p string) (string, error) {
@@ -182,30 +184,52 @@ func (self *jsre) exec(filename string) error {
 }
 
 func (self *jsre) interactive() {
-	for {
-		input, err := self.Prompt(self.ps1)
-		if err != nil {
-			break
-		}
-		if input == "" {
-			continue
-		}
-		str += input + "\n"
-		self.setIndent()
-		if indentCount <= 0 {
-			if input == "exit" {
-				break
+	// Read input lines.
+	prompt := make(chan string)
+	inputln := make(chan string)
+	go func() {
+		defer close(inputln)
+		for {
+			line, err := self.Prompt(<-prompt)
+			if err != nil {
+				return
+			}
+			inputln <- line
+		}
+	}()
+	// Wait for Ctrl-C, too.
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, os.Interrupt)
+
+	defer func() {
+		if self.atexit != nil {
+			self.atexit()
+		}
+		self.re.Stop(false)
+	}()
+	for {
+		prompt <- self.ps1
+		select {
+		case <-sig:
+			fmt.Println("caught interrupt, exiting")
+			return
+		case input, ok := <-inputln:
+			if !ok || indentCount <= 0 && input == "exit" {
+				return
+			}
+			if input == "" {
+				continue
+			}
+			str += input + "\n"
+			self.setIndent()
+			if indentCount <= 0 {
+				hist := str[:len(str)-1]
+				self.AppendHistory(hist)
+				self.parseInput(str)
+				str = ""
 			}
-			hist := str[:len(str)-1]
-			self.AppendHistory(hist)
-			self.parseInput(str)
-			str = ""
 		}
 	}
-	if self.atexit != nil {
-		self.atexit()
-	}
-	self.re.Stop(false)
 }
 
 func (self *jsre) withHistory(op func(*os.File)) {