Merge pull request #1795 from wxiaoguang/fix-nil-flag

Fix nil HelpFlag panic (v2)

help.go

@@ -415,6 +415,9 @@ func checkVersion(cCtx *Context) bool {
 }
 
 func checkHelp(cCtx *Context) bool {
+	if HelpFlag == nil {
+		return false
+	}
 	found := false
 	for _, name := range HelpFlag.Names() {
 		if cCtx.Bool(name) {
@@ -426,24 +429,6 @@ func checkHelp(cCtx *Context) bool {
 	return found
 }
 
-func checkCommandHelp(c *Context, name string) bool {
-	if c.Bool("h") || c.Bool("help") {
-		_ = ShowCommandHelp(c, name)
-		return true
-	}
-
-	return false
-}
-
-func checkSubcommandHelp(cCtx *Context) bool {
-	if cCtx.Bool("h") || cCtx.Bool("help") {
-		_ = ShowSubcommandHelp(cCtx)
-		return true
-	}
-
-	return false
-}
-
 func checkShellCompleteFlag(a *App, arguments []string) (bool, []string) {
 	if !a.EnableBashCompletion {
 		return false, arguments

help_test.go

@@ -101,6 +101,26 @@ func Test_Help_Custom_Flags(t *testing.T) {
 	}
 }
 
+func Test_Help_Nil_Flags(t *testing.T) {
+	oldFlag := HelpFlag
+	defer func() {
+		HelpFlag = oldFlag
+	}()
+	HelpFlag = nil
+
+	app := App{
+		Action: func(context *Context) error {
+			return nil
+		},
+	}
+	output := new(bytes.Buffer)
+	app.Writer = output
+	_ = app.Run([]string{"test"})
+	if output.Len() > 0 {
+		t.Errorf("unexpected output: %s", output.String())
+	}
+}
+
 func Test_Version_Custom_Flags(t *testing.T) {
 	oldFlag := VersionFlag
 	defer func() {

suggestions.go

@@ -21,7 +21,7 @@ func suggestFlag(flags []Flag, provided string, hideHelp bool) string {
 
 	for _, flag := range flags {
 		flagNames := flag.Names()
-		if !hideHelp {
+		if !hideHelp && HelpFlag != nil {
 			flagNames = append(flagNames, HelpFlag.Names()...)
 		}
 		for _, name := range flagNames {