completion does not respect global arguments

[laishulu]

Rust Version

rustc -V

Affected Version of clap

clap 2.20.0

Expected Behavior Summary

1. global-arg is a global arg of myapp which can be used in subcmd, i.e both myapp --global-arg subcmd and myapp subcmd --global-arg work
2. when I type myapp subcmd --[tab], global-arg should pops up.

Actual Behavior Summary

when I type myapp subcmd --[tab], global-arg does not show up

[kbknapp]

Three questions for you:

• Can you post a link to the code, or a snippet of the code you're trying to use?
• Which shell are you using?
• Does the myapp or subcmd have an underscore in the name? (_). If so, this could be from Using a binary name with an underscore leads to panic on completion generation #581 which I'm currently working on and have almost ready to PR.

[laishulu]

                    app.gen_completions_to("myapp",
                                           Shell::Zsh,
                                           &mut io::stdout())

I use zsh. underscore is in nowhere.

[kbknapp]

Alright, I have this fixed, once #842 merges I'll start the new PR