[MERGE] Don't ask a password if there is no real terminal. (#69851)

[Alexander Belchenko]

Jeremy Wilkins пишет:
> Must admit I'm not following this but I've got a different UIFactory
> for the (rather crude) TextMate integration - hence bzr will run
> without a terminal but can still ask for a password (uses
> cocoadialog).
> 
> Presumably this shouldn't break that?

I suppose all should be fine. My patch explicitly changed behavior of
method get_non_echoed_password in the class CLIUIFactory. If your
approach simply overloading get_password method you should not be affected
at all by my change.

Here the body of get_non_echoed_password. It's all about interaction with
terminal:

     def get_non_echoed_password(self, prompt):
         encoding = osutils.get_terminal_encoding()
         return getpass.getpass(prompt.encode(encoding, 'replace'))

The problem with redirected stdin in subprocess call is exactly in
getpass.