| Index: src/flag/flag.go |
| =================================================================== |
| --- a/src/flag/flag.go |
| +++ b/src/flag/flag.go |
| @@ -406,6 +406,7 @@ func defaultUsage(f *FlagSet) { |
| // for how to write your own usage function. |
| // Usage prints to standard error a usage message documenting all defined command-line flags. |
| +// It is called when an error occurs while parsing flags. |
| // The function is a variable that may be changed to point to a custom function. |
| var Usage = func() { |
| fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0]) |
| @@ -702,13 +703,15 @@ func (f *FlagSet) failf(format string, a |
| return err |
| } |
| -// usage calls the Usage method for the flag set, or the usage function if |
| -// the flag set is CommandLine. |
| +// usage calls the Usage method for the flag set if one is specified, |
| +// or the appropriate default usage function otherwise. |
| func (f *FlagSet) usage() { |
| - if f == CommandLine { |
| - Usage() |
| - } else if f.Usage == nil { |
| - defaultUsage(f) |
| + if f.Usage == nil { |
| + if f == CommandLine { |
| + Usage() |
| + } else { |
| + defaultUsage(f) |
| + } |
| } else { |
| f.Usage() |
| } |
| @@ -757,6 +760,7 @@ func (f *FlagSet) parseOne() (bool, erro |
| } |
| return false, f.failf("flag provided but not defined: -%s", name) |
| } |
| + |
| if fv, ok := flag.Value.(boolFlag); ok && fv.IsBoolFlag() { // special case: doesn't need an arg |
| if has_value { |
| if err := fv.Set(value); err != nil { |
