Context.IsSet returns false even if StringSlice flag is set

[disktnk]

On my environment (mac OS X 10.10.5), Context.IsSet does not work when using StringSliceFlag .

// `cmd` is a "sub_command" object
cmd.Flags = []cli.Flag{
    cli.StringFlag{
        Name:   "string_arg, s",
        Value:  "",
        Usage:  "snip",
    },
    cli.StringSliceFlag{
        Name:  "string_slice_arg, a",
        Value: &cli.StringSlice{},
        Usage: "snip",
    },
}

// ...snip

fmt.Println(c.IsSet("string_arg"))
fmt.Println(c.IsSet("string_slice_arg"))

./go_binary sub_command -s str1 -a str2
true
false

[meatballhat]

Confirmed! Oddly, I'm seeing different behavior when calling IsSet with "short" vs "long" flag names (see gist). Still investigating...

[meatballhat]

😑 https://github.com/codegangsta/cli/blob/222ec6fb7eb8a3da24cfa4017694ba45e3f1f516/context.go#L363-L369

[jszwedko]

Hmmm, interesting, seems to have been introduced in #73

[meatballhat]

Yeppers. My initial attempt to solve this is made more awkward by the slice types being aliases rather than composites. It might be easiest to address this after the merge of #350.

[meatballhat]

I'm going to see if I can tack this bugfix onto #350 yep yep.

[jszwedko]

Fixed by #392 (will be released is v2, but you can use that branch for now if you need the functionality sooner!).