Include --help and --version flag in completion

Fixes #1786

The --help, -h, --version and -v flags are normally added when the
`execute()` function is called on a command.  When doing completion
we don't call `execute()` so we need to add these flags explicitly to
the command being completed.

Also, we disable all further completions if the 'help' or 'version'
flags are present on the command-line.

Merge spf13/cobra#1813

command.go

@@ -32,6 +32,8 @@ import (
 	"github.com/zulucmd/zulu/internal/util"
 )
 
+const FlagSetByCobraAnnotation = "cobra_annotation_flag_set_by_cobra"
+
 //go:embed templates/*
 var tmplFS embed.FS
 
@@ -1208,7 +1210,7 @@ func (c *Command) InitDefaultHelpFlag() {
 		} else {
 			usage += c.Name()
 		}
-		c.Flags().Bool("help", false, usage, zflag.OptShorthand('h'))
+		c.Flags().Bool("help", false, usage, zflag.OptShorthand('h'), zflag.OptAnnotation(FlagSetByCobraAnnotation, []string{"true"}))
 	}
 }
 
@@ -1230,7 +1232,9 @@ func (c *Command) InitDefaultVersionFlag() {
 			usage += c.Name()
 		}
 
-		var opts []zflag.Opt
+		opts := []zflag.Opt{
+			zflag.OptAnnotation(FlagSetByCobraAnnotation, []string{"true"}),
+		}
 		if c.Flags().ShorthandLookup('v') == nil {
 			opts = append(opts, zflag.OptShorthand('v'))
 		}

completions.go

@@ -250,6 +250,12 @@ func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDi
 	}
 	finalCmd.ctx = c.ctx
 
+	// These flags are normally added when `execute()` is called on `finalCmd`,
+	// however, when doing completion, we don't call `finalCmd.execute()`.
+	// Let's add the --help and --version flag ourselves.
+	finalCmd.InitDefaultHelpFlag()
+	finalCmd.InitDefaultVersionFlag()
+
 	// Check if we are doing flag value completion before parsing the flags.
 	// This is important because if we are completing a flag value, we need to also
 	// remove the flag name argument from the list of finalArgs or else the parsing
@@ -282,6 +288,12 @@ func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDi
 		}
 	}
 
+	// Look for the --help or --version flags.  If they are present,
+	// there should be no further completions.
+	if helpOrVersionFlagPresent(finalCmd) {
+		return finalCmd, []string{}, ShellCompDirectiveNoFileComp, nil
+	}
+
 	// We only remove the flags from the arguments if DisableFlagParsing is not set.
 	// This is important for commands which have requested to do their own flag completion.
 	if !finalCmd.DisableFlagParsing {
@@ -451,6 +463,18 @@ func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDi
 	return finalCmd, completions, directive, nil
 }
 
+func helpOrVersionFlagPresent(cmd *Command) bool {
+	if versionFlag := cmd.Flags().Lookup("version"); versionFlag != nil &&
+		len(versionFlag.Annotations[FlagSetByCobraAnnotation]) > 0 && versionFlag.Changed {
+		return true
+	}
+	if helpFlag := cmd.Flags().Lookup("help"); helpFlag != nil &&
+		len(helpFlag.Annotations[FlagSetByCobraAnnotation]) > 0 && helpFlag.Changed {
+		return true
+	}
+	return false
+}
+
 func getFlagNameCompletions(flag *zflag.Flag, toComplete string) []string {
 	if nonCompletableFlag(flag) {
 		return []string{}