Re: [PATCH 1/2] git-svn, perl/Git.pm: add central method for prompting passwords honoring GIT_ASKPASS and SSH_ASKPASS

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 4, 2012, 19:08 UTC
Message-ID: <7vipkrp9pq.fsf@alter.siamese.dyndns.org>
In-Reply-To: <4F040E46.5030001@tu-clausthal.de>

Sven Strickroth <sven.strickroth@tu-clausthal.de> writes:

Show 13 quoted lines

> Am 04.01.2012 08:55 schrieb Sven Strickroth:
>> The Git.pm part is easy, but I also tried to update prompt.c (untested).
>
> I said "easy" and then I mailed the wrong/outdated patch :(
> I'm sorry for the noise.
>
> From: Sven Strickroth <email@cs-ware.de>
> Date: Wed, 4 Jan 2012 08:44:48 +0100
> Subject: [PATCH] Git.pm, prompt: try reading from interactive terminal
>  before using SSH_ASKPASS
>
> SVN tries to read reading from interactive terminal before using
> SSH_ASKPASS helper. This change adjust git to behave the same way.

It might be an accurate description of what Subversion does ("tries to" is the key phrase). I however do not know if it is equivalent to what your patch does.

When GIT_ASKPASS is not set, the $prompt is given to the standard error stream unconditionally and then the "require Term::ReadKey" codepath is used. When the terminal is unavailable, you might get undef in $ret and be able to fall back on SSH_ASKPASS part, but you cannot take back the noise you have given to the standard error stream.

Is there a way to ask Term::ReadKey (or possibly some other module) if we will be able to interact with the terminal _before_ we give that prompt?

The simplest would be to do this, I would think, but I didn't test it.

	if (!defined $ret && -t) {
		print STDERR $prompt;
		if ($isPassword) {
                	...
	}
        if (!defined $ret) {
		$ret = _prompt($ENV{'SSH_ASKPASS'}, $prompt);
	}