From 6a465500bc3844259013ba62e0686dc030dcf1ea Mon Sep 17 00:00:00 2001
From: Zachary Yedidia <zyedidia@gmail.com>
Date: Mon, 6 Jan 2020 11:38:21 -0500
Subject: [PATCH] Properly handle empty args with new shellquote lib

Fixes #1454
---
 internal/action/actions.go            |  6 +++++-
 internal/action/command.go            |  7 +++++++
 internal/action/terminal_supported.go |  3 +++
 internal/shell/shell.go               | 10 ++++++++++
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/internal/action/actions.go b/internal/action/actions.go
index a85f7bbb..b48cf82a 100644
--- a/internal/action/actions.go
+++ b/internal/action/actions.go
@@ -667,11 +667,15 @@ func (h *BufPane) SaveAs() bool {
 		if !canceled {
 			// the filename might or might not be quoted, so unquote first then join the strings.
 			args, err := shellquote.Split(resp)
-			filename := strings.Join(args, " ")
 			if err != nil {
 				InfoBar.Error("Error parsing arguments: ", err)
 				return
 			}
+			if len(args) == 0 {
+				InfoBar.Error("No filename given")
+				return
+			}
+			filename := strings.Join(args, " ")
 			noPrompt := h.saveBufToFile(filename, "SaveAs")
 			if noPrompt {
 				h.completeAction("SaveAs")
diff --git a/internal/action/command.go b/internal/action/command.go
index 1d88d8cc..4960ae9e 100644
--- a/internal/action/command.go
+++ b/internal/action/command.go
@@ -349,6 +349,9 @@ func (h *BufPane) OpenCmd(args []string) {
 			InfoBar.Error("Error parsing args ", err)
 			return
 		}
+		if len(args) == 0 {
+			return
+		}
 		filename = strings.Join(args, " ")
 
 		open := func() {
@@ -966,6 +969,10 @@ func (h *BufPane) HandleCommand(input string) {
 		return
 	}
 
+	if len(args) == 0 {
+		return
+	}
+
 	inputCmd := args[0]
 
 	if _, ok := commands[inputCmd]; !ok {
diff --git a/internal/action/terminal_supported.go b/internal/action/terminal_supported.go
index b0b10632..3ae19ff1 100644
--- a/internal/action/terminal_supported.go
+++ b/internal/action/terminal_supported.go
@@ -14,6 +14,9 @@ func RunTermEmulator(h *BufPane, input string, wait bool, getOutput bool, callba
 	if err != nil {
 		return err
 	}
+	if len(args) == 0 {
+		return nil
+	}
 
 	t := new(shell.Terminal)
 	t.Start(args, getOutput, wait, callback, userargs)
diff --git a/internal/shell/shell.go b/internal/shell/shell.go
index 24df587f..53bf67ce 100644
--- a/internal/shell/shell.go
+++ b/internal/shell/shell.go
@@ -2,6 +2,7 @@ package shell
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -36,6 +37,9 @@ func RunCommand(input string) (string, error) {
 	if err != nil {
 		return "", err
 	}
+	if len(args) == 0 {
+		return "", errors.New("No arguments")
+	}
 	inputCmd := args[0]
 
 	return ExecCommand(inputCmd, args[1:]...)
@@ -49,6 +53,9 @@ func RunBackgroundShell(input string) (func() string, error) {
 	if err != nil {
 		return nil, err
 	}
+	if len(args) == 0 {
+		return nil, errors.New("No arguments")
+	}
 	inputCmd := args[0]
 	return func() string {
 		output, err := RunCommand(input)
@@ -72,6 +79,9 @@ func RunInteractiveShell(input string, wait bool, getOutput bool) (string, error
 	if err != nil {
 		return "", err
 	}
+	if len(args) == 0 {
+		return "", errors.New("No arguments")
+	}
 	inputCmd := args[0]
 
 	// Shut down the screen because we're going to interact directly with the shell