bug#30190: 27.0.50; term run in line mode shows user passwords

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

> I have the bias/personal-preference to avoid load new things when
> I make a change.  Let's call it: 'disturb the least' with my patches.

I'd prefer to re-use comint code rather than copy it.  Copying might be
tolerable for term-watch-for-password-prompt (it could conceivably
require adjustments for the context of term-mode), but it's out of the
question for term-password-prompt-regexp.

> My patch just tried to mimic what is done in `comint.el' and reproduce
> it in `term.el'.  My hope was that the patch would be accepted frictionless:
> if it's already done in `comint.el', why not doing the same in `term.el'?

I'm not a great fan of the hooks in comint (tho I must say I haven't
come up with anything really better either).

And to the extent that you can set *-password-prompt-regexp
buffer-locally in order to prevent *-watch-for-password-prompt from
getting in the way, I don't see much benefit of going through a hook.
[ The hook might be beneficial in itself, with a nil default value, but
  that's a different discussion.  ]


        Stefan