request explicit return from subprocess

Previously we were recording output from subprocesses using a multiwriter
and hooking that up to the cmd's stdout to write to both os.Stdout and
a buffer. We would then display the output after the program finished.

This worked well for commands like 'ls' but not for commands like 'vi'
which expect you to be in a tty, and when you've got the cmd's stdout
pointing at a multiwriter, the subprogram thinks we're not in a tty
and then things like terminal corruption can happen. This was the case
with neovim, and even in vim a warning was given with a pause before
starting the program.

Now we're chucking out the multiwriter and instead making it that you
need to press enter after the program has finished to return to lazygit.
This allows you to view the output of the program (e.g. if it's ls) and
then decide that you want to return. It's one level of unnecessary
redirection for editors like vim, but even they could potentially have
output to stderr/stdout that you want to look at before returning.

 Please enter the commit message for your changes. Lines starting

4 files changed, 28 insertions, 29 deletions

diff --git a/pkg/gui/gui.go b/pkg/gui/gui.go
index 04ed13554..ce339e61f 100644
--- a/pkg/gui/gui.go
+++ b/pkg/gui/gui.go
@@ -1,8 +1,8 @@
 package gui
 
 import (
-	"bytes"
-	"io"
+	"fmt"
+	"io/ioutil"
 	"math"
 	"os"
 	"sync"
@@ -10,7 +10,6 @@ import (
 	// "io"
 	// "io/ioutil"
 
-	"io/ioutil"
 	"os/exec"
 	"strings"
 	"time"
@@ -147,7 +146,6 @@ type guiState struct {
 	WorkingTreeState    string // one of "merging", "rebasing", "normal"
 	Contexts            map[string]string
 	CherryPickedCommits []*commands.Commit
-	SubProcessOutput    string
 }
 
 // NewGui builds a new gui handler
@@ -517,16 +515,6 @@ func (gui *Gui) layout(g *gocui.Gui) error {
 		}
 	}
 
-	if gui.State.SubProcessOutput != "" {
-		output := gui.State.SubProcessOutput
-		gui.State.SubProcessOutput = ""
-		x, y := gui.g.Size()
-		// if we just came back from vim, we don't want vim's output to show up in our popup
-		if float64(len(output))*1.5 < float64(x*y) {
-			return gui.createMessagePanel(gui.g, nil, "Output", output)
-		}
-	}
-
 	type listViewState struct {
 		selectedLine int
 		lineCount    int
@@ -695,15 +683,9 @@ func (gui *Gui) RunWithSubprocesses() error {
 			} else if err == gui.Errors.ErrSwitchRepo {
 				continue
 			} else if err == gui.Errors.ErrSubProcess {
-				output, err := gui.runCommand(gui.SubProcess)
-				if err != nil {
+				if err := gui.runCommand(); err != nil {
 					return err
 				}
-				gui.State.SubProcessOutput = output
-				gui.SubProcess.Stdout = ioutil.Discard
-				gui.SubProcess.Stderr = ioutil.Discard
-				gui.SubProcess.Stdin = nil
-				gui.SubProcess = nil
 			} else {
 				return err
 			}
@@ -712,20 +694,28 @@ func (gui *Gui) RunWithSubprocesses() error {
 	return nil
 }
 
-func (gui *Gui) runCommand(cmd *exec.Cmd) (string, error) {
-	var stdoutBuf bytes.Buffer
-	cmd.Stdout = io.MultiWriter(os.Stdout, &stdoutBuf)
-	cmd.Stderr = io.MultiWriter(os.Stderr, &stdoutBuf)
-	cmd.Stdin = os.Stdin
+func (gui *Gui) runCommand() error {
+	gui.SubProcess.Stdout = os.Stdout
+	gui.SubProcess.Stderr = os.Stdout
+	gui.SubProcess.Stdin = os.Stdin
 
-	if err := cmd.Run(); err != nil {
+	fmt.Fprintf(os.Stdout, "\n%s\n\n", utils.ColoredString("+ "+strings.Join(gui.SubProcess.Args, " "), color.FgBlue))
+
+	if err := gui.SubProcess.Run(); err != nil {
 		// not handling the error explicitly because usually we're going to see it
 		// in the output anyway
 		gui.Log.Error(err)
 	}
 
-	outStr := stdoutBuf.String()
-	return outStr, nil
+	gui.SubProcess.Stdout = ioutil.Discard
+	gui.SubProcess.Stderr = ioutil.Discard
+	gui.SubProcess.Stdin = nil
+	gui.SubProcess = nil
+
+	fmt.Fprintf(os.Stdout, "\n%s", utils.ColoredString(gui.Tr.SLocalize("pressEnterToReturn"), color.FgGreen))
+	fmt.Scanln() // wait for enter press
+
+	return nil
 }
 
 func (gui *Gui) quit(g *gocui.Gui, v *gocui.View) error {
diff --git a/pkg/i18n/dutch.go b/pkg/i18n/dutch.go
index 97b49e76d..6774928fd 100644
--- a/pkg/i18n/dutch.go
+++ b/pkg/i18n/dutch.go
@@ -736,6 +736,9 @@ func addDutch(i18nObject *i18n.Bundle) error {
 		}, &i18n.Message{
 			ID:    "resetTo",
 			Other: `reset to`,
+		}, &i18n.Message{
+			ID:    "pressEnterToReturn",
+			Other: "Press enter to return to lazygit",
 		},
 	)
 }
diff --git a/pkg/i18n/english.go b/pkg/i18n/english.go
index 291f114e8..36fb3e021 100644
--- a/pkg/i18n/english.go
+++ b/pkg/i18n/english.go
@@ -759,6 +759,9 @@ func addEnglish(i18nObject *i18n.Bundle) error {
 		}, &i18n.Message{
 			ID:    "resetTo",
 			Other: `reset to`,
+		}, &i18n.Message{
+			ID:    "pressEnterToReturn",
+			Other: "Press enter to return to lazygit",
 		},
 	)
 }
diff --git a/pkg/i18n/polish.go b/pkg/i18n/polish.go
index 8229dc5df..c165ea2f0 100644
--- a/pkg/i18n/polish.go
+++ b/pkg/i18n/polish.go
@@ -719,6 +719,9 @@ func addPolish(i18nObject *i18n.Bundle) error {
 		}, &i18n.Message{
 			ID:    "resetTo",
 			Other: `reset to`,
+		}, &i18n.Message{
+			ID:    "pressEnterToReturn",
+			Other: "Press enter to return to lazygit",
 		},
 	)
 }