Merge pull request #2438 from SulimanAbdulrazzaq/fix/short-option-multibyte-last-flag

fix: handle a multi-byte flag at the end of a short option group

Author: Juneezee

command_parse.go

@@ -212,6 +212,11 @@ func (cmd *Command) parseFlags(args Args) (Args, error) {
 			return &stringSliceArgs{posArgs}, fmt.Errorf("%s%s", providedButNotDefinedErrMsg, flagName)
 		}
 
+		// ranging over flagName yields byte offsets, so the last flag starts
+		// where its rune starts, which is not len-1 for a multi-byte rune
+		_, lastSize := utf8.DecodeLastRuneInString(flagName)
+		lastIndex := len(flagName) - lastSize
+
 		// try to split the flags
 		for index, c := range flagName {
 			tracef("processing flag (fName=%[1]q)", string(c))
@@ -223,7 +228,7 @@ func (cmd *Command) parseFlags(args Args) (Args, error) {
 				return &stringSliceArgs{posArgs}, fmt.Errorf("%s%s", providedButNotDefinedErrMsg, flagName)
 			} else if fb, ok := sf.(boolFlag); ok && fb.IsBoolFlag() {
 				fv := flagVal
-				if index == (len(flagName)-1) && flagVal == "" {
+				if index == lastIndex && flagVal == "" {
 					fv = "true"
 				}
 				if fv == "" {
@@ -233,7 +238,7 @@ func (cmd *Command) parseFlags(args Args) (Args, error) {
 					tracef("processing flag.2 (fName=%[1]q)", string(c))
 					return &stringSliceArgs{posArgs}, err
 				}
-			} else if index == len(flagName)-1 { // last flag can take an arg
+			} else if index == lastIndex { // last flag can take an arg
 				if flagVal == "" {
 					if len(rargs) == 1 {
 						return &stringSliceArgs{posArgs}, fmt.Errorf("%s%s", argumentNotProvidedErrMsg, string(c))

command_test.go

@@ -1494,6 +1494,40 @@ func TestCommand_UseShortOptionHandling_missing_value(t *testing.T) {
 	assert.EqualError(t, err, "flag needs an argument: -n")
 }
 
+func TestCommand_UseShortOptionHandlingMultiByteLastFlag(t *testing.T) {
+	const name = "ש"
+
+	var verbose bool
+	var value string
+	var args []string
+	newCmd := func() *Command {
+		return &Command{
+			Name:                   "app",
+			UseShortOptionHandling: true,
+			Flags: []Flag{
+				&BoolFlag{Name: "v"},
+				&StringFlag{Name: name},
+			},
+			Action: func(_ context.Context, cmd *Command) error {
+				verbose = cmd.Bool("v")
+				value = cmd.String(name)
+				args = cmd.Args().Slice()
+				return nil
+			},
+			Writer:    io.Discard,
+			ErrWriter: io.Discard,
+		}
+	}
+
+	require.NoError(t, newCmd().Run(buildTestContext(t), []string{"app", "-v" + name, "value", "operand"}))
+	assert.True(t, verbose)
+	assert.Equal(t, "value", value)
+	assert.Equal(t, []string{"operand"}, args)
+
+	err := newCmd().Run(buildTestContext(t), []string{"app", "-v" + name})
+	assert.EqualError(t, err, "flag needs an argument: "+name)
+}
+
 func TestCommand_UseShortOptionHandlingCommand(t *testing.T) {
 	var (
 		one, two bool