fix: disable bash completion if double dash is included in arguments

- #1932

Author: suzuki-shunsuke

help.go

@@ -248,7 +248,6 @@ func ShowCommandHelpAndExit(c *Context, command string, code int) {
 
 // ShowCommandHelp prints help for the given command
 func ShowCommandHelp(ctx *Context, command string) error {
-
 	commands := ctx.App.Commands
 	if ctx.Command.Subcommands != nil {
 		commands = ctx.Command.Subcommands
@@ -337,15 +336,13 @@ func ShowCommandCompletions(ctx *Context, command string) {
 			DefaultCompleteWithFlags(c)(ctx)
 		}
 	}
-
 }
 
 // printHelpCustom is the default implementation of HelpPrinterCustom.
 //
 // The customFuncs map will be combined with a default template.FuncMap to
 // allow using arbitrary functions in template rendering.
 func printHelpCustom(out io.Writer, templ string, data interface{}, customFuncs map[string]interface{}) {
-
 	const maxLineLength = 10000
 
 	funcMap := template.FuncMap{
@@ -450,6 +447,15 @@ func checkShellCompleteFlag(a *App, arguments []string) (bool, []string) {
 		return false, arguments
 	}
 
+	for _, arg := range arguments {
+		// If arguments include "--", shell completion is disabled
+		// because after "--" only positional arguments are accepted.
+		// https://unix.stackexchange.com/a/11382
+		if arg == "--" {
+			return false, arguments
+		}
+	}
+
 	return true, arguments[:pos]
 }
 
@@ -499,7 +505,6 @@ func wrap(input string, offset int, wrapAt int) string {
 				ss = append(ss, wrapped)
 			} else {
 				ss = append(ss, padding+wrapped)
-
 			}
 
 		}

help_test.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"reflect"
 	"runtime"
 	"strings"
 	"testing"
@@ -1349,7 +1350,6 @@ func TestWrap(t *testing.T) {
 }
 
 func TestWrappedHelp(t *testing.T) {
-
 	// Reset HelpPrinter after this test.
 	defer func(old helpPrinter) {
 		HelpPrinter = old
@@ -1359,7 +1359,8 @@ func TestWrappedHelp(t *testing.T) {
 	app := &App{
 		Writer: output,
 		Flags: []Flag{
-			&BoolFlag{Name: "foo",
+			&BoolFlag{
+				Name:    "foo",
 				Aliases: []string{"h"},
 				Usage:   "here's a really long help text line, let's see where it wraps. blah blah blah and so on.",
 			},
@@ -1443,7 +1444,6 @@ COPYRIGHT:
 }
 
 func TestWrappedCommandHelp(t *testing.T) {
-
 	// Reset HelpPrinter after this test.
 	defer func(old helpPrinter) {
 		HelpPrinter = old
@@ -1504,7 +1504,6 @@ OPTIONS:
 }
 
 func TestWrappedSubcommandHelp(t *testing.T) {
-
 	// Reset HelpPrinter after this test.
 	defer func(old helpPrinter) {
 		HelpPrinter = old
@@ -1573,7 +1572,6 @@ OPTIONS:
 }
 
 func TestWrappedHelpSubcommand(t *testing.T) {
-
 	// Reset HelpPrinter after this test.
 	defer func(old helpPrinter) {
 		HelpPrinter = old
@@ -1714,3 +1712,65 @@ GLOBAL OPTIONS:
 			output.String(), expected)
 	}
 }
+
+func Test_checkShellCompleteFlag(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name                string
+		app                 *App
+		arguments           []string
+		wantShellCompletion bool
+		wantArgs            []string
+	}{
+		{
+			name:                "disable bash completion",
+			arguments:           []string{"--generate-bash-completion"},
+			app:                 &App{},
+			wantShellCompletion: false,
+			wantArgs:            []string{"--generate-bash-completion"},
+		},
+		{
+			name:      "--generate-bash-completion isn't used",
+			arguments: []string{"foo"},
+			app: &App{
+				EnableBashCompletion: true,
+			},
+			wantShellCompletion: false,
+			wantArgs:            []string{"foo"},
+		},
+		{
+			name:      "arguments include double dash",
+			arguments: []string{"--", "foo", "--generate-bash-completion"},
+			app: &App{
+				EnableBashCompletion: true,
+			},
+			wantShellCompletion: false,
+			wantArgs:            []string{"--", "foo", "--generate-bash-completion"},
+		},
+		{
+			name:      "--generate-bash-completion",
+			arguments: []string{"foo", "--generate-bash-completion"},
+			app: &App{
+				EnableBashCompletion: true,
+			},
+			wantShellCompletion: true,
+			wantArgs:            []string{"foo"},
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			shellCompletion, args := checkShellCompleteFlag(tt.app, tt.arguments)
+			if tt.wantShellCompletion != shellCompletion {
+				t.Errorf("Unexpected shell completion, got:\n%v\nexpected: %v",
+					shellCompletion, tt.wantShellCompletion)
+			}
+			if !reflect.DeepEqual(tt.wantArgs, args) {
+				t.Errorf("Unexpected arguments, got:\n%v\nexpected: %v",
+					args, tt.wantArgs)
+			}
+		})
+	}
+}