git: fix editor command split rule

Editor commands with quoting, like:

vim -c 'set tw=74' -c 'set noai' -c 'set wrap'

were being splitted in the wrong way: only spaces were being considered and
each part was placed in a different slot of the command arg array:

[vim, -c, 'set, tw=74', -c, 'set, noai', -c, 'set, wrap']

With that, lab ended up calling `vim` with strings like `'set` and `tw=74'`
as separated args and, thus, vim was creating files with these names instead
of using them as real arguments for the `-c` flag.

This commit fixes it by using Google's shlex module, which respects
shell-style rules for quoting and commenting in the command line. The
previous example is now splitted as follows:

[vim, -c, 'set tw=74', -c, 'set noai', -c, 'set wrap']

So the quoted values are kept together.

Fixes: b73579a ("git: fix edit command when using extra args")
Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>

go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/gdamore/tcell/v2 v2.4.1-0.20210905002822-f057f0a857a1
 	github.com/go-git/go-git/v5 v5.4.2
 	github.com/google/go-querystring v1.1.0 // indirect
+	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
 	github.com/hashicorp/go-cleanhttp v0.5.2 // indirect
 	github.com/hashicorp/go-retryablehttp v0.7.0 // indirect
 	github.com/jaytaylor/html2text v0.0.0-20200412013138-3577fbdbcff7

go.sum

@@ -226,6 +226,8 @@ github.com/google/pprof v0.0.0-20210601050228-01bbb1931b22/go.mod h1:kpwsk12EmLe
 github.com/google/pprof v0.0.0-20210609004039-a478d1d731e9/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/pprof v0.0.0-20210720184732-4bb14d4b1be1/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=

internal/git/edit.go

@@ -8,6 +8,8 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
+
+	"github.com/google/shlex"
 )
 
 // Edit opens a file in the users editor and returns the title and body.
@@ -51,7 +53,12 @@ func EditFile(filePrefix, message string) (string, error) {
 		}
 	}
 
-	cmd := editorCMD(editor, filePath)
+	cmd, err := editorCMD(editor, filePath)
+	if err != nil {
+		fmt.Printf("ERROR(editorCMD): failed to get editor command \"%s\"\n", editor)
+		return "", err
+	}
+
 	err = cmd.Run()
 	if err != nil {
 		fmt.Printf("ERROR(cmd): Saved file contents written to %s\n", filePath)
@@ -88,7 +95,7 @@ func editor() (string, error) {
 	return editor, nil
 }
 
-func editorCMD(editor, filePath string) *exec.Cmd {
+func editorCMD(editor, filePath string) (*exec.Cmd, error) {
 	// make 'vi' the default editor to avoid empty editor configs
 	if editor == "" {
 		editor = "vi"
@@ -100,7 +107,12 @@ func editorCMD(editor, filePath string) *exec.Cmd {
 		args = append(args, "--cmd", "set ft=gitcommit tw=0 wrap lbr")
 	}
 
-	parts := strings.Split(editor, " ")
+	// Split editor command using shell rules for quoting and commenting
+	parts, err := shlex.Split(editor)
+	if err != nil {
+		return nil, err
+	}
+
 	name := parts[0]
 	if len(parts) > 0 {
 		for _, arg := range parts[1:] {
@@ -114,7 +126,7 @@ func editorCMD(editor, filePath string) *exec.Cmd {
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
-	return cmd
+	return cmd, nil
 }
 
 func removeComments(message string) (string, error) {

internal/git/edit_test.go

@@ -91,8 +91,11 @@ func TestEditor(t *testing.T) {
 		require.NotEmpty(t, editor)
 	})
 	t.Run("Open Editor", func(t *testing.T) {
-		cmd := editorCMD(path, filePath)
-		err := cmd.Start()
+		cmd, err := editorCMD(path, filePath)
+		if err != nil {
+			t.Fatal(err)
+		}
+		err = cmd.Start()
 		if err != nil {
 			t.Fatal(err)
 		}