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

Sven Strickroth [off-list ref] writes:

Am 04.01.2012 08:55 schrieb Sven Strickroth:

quoted

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I said "easy" and then I mailed the wrong/outdated patch :(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 <redacted>
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);
	}

Hi,

Am 04.01.2012 20:08 schrieb Junio C Hamano:

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) {
                	...
	}

-t does not help, but I think it's not a big deal if the prompt is printed on
the terminal and also on the ASKPASS-helper.

Using Term::ReadLine seems to help:
...
		$ret = _prompt($ENV{'SSH_ASKPASS'}, $prompt);
	}
	if (!defined $ret) {
		use Term::Readline;
		my $term = Term::ReadLine->new("Git.pm");
		if ($isPassword) {
			require Term::ReadKey;
			Term::ReadKey::ReadMode('noecho');
		}
		$ret = $term->readline($prompt);
		if ($isPassword) {
			Term::ReadKey::ReadMode('restore');
			print STDERR "\n";
			
		}
	}
	if (!defined $ret) {
		$ret = _prompt($ENV{'SSH_ASKPASS'}, $prompt);
...

But I'm not sure if this is what we want, because you can go with the cursor
over the whole terminal.

A better (working) alternative might be:
...
		$ret = _prompt($ENV{'SSH_ASKPASS'}, $prompt);
	}
	use Term::Readline;
	my $term = Term::ReadLine->new("Git.pm");
	if (!defined $ret && fileno($term->IN)) {
 		print STDERR $prompt;
 		if ($isPassword) {
                 	...
 	}
...

-- 
Best regards,
 Sven Strickroth
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