From: Jonathan Nieder <jrnieder@gmail.com>
Date: Wed, 14 Dec 2011 23:31:19 GMT
Subject: Re: tr/pty-all (Re: What's cooking in git.git (Dec 2011, #04; Tue, 13))
Message-ID: <20111214233119.GA2354@elie>
In-Reply-To: <20111214232151.GB13128@sigill.intra.peff.net>

Jeff King wrote:

[...]
> A test which accidentally reads stdin would soak up all of
> the rest of the input intended for the outer shell loop.
> 
> Let's redirect stdin from a known source to eliminate
> variation. We could just connect it to /dev/null. However,
> tests which accidentally read stdin would then see immediate
> EOF, which may or may not cause them to notice the errror.
[...]
> +++ b/t/test-lib.sh
[...]
> @@ -469,7 +471,7 @@ test_debug () {
>  test_eval_ () {
>  	# This is a separate function because some tests use
>  	# "return" to end a test_expect_success block early.
> -	eval >&3 2>&4 "$*"
> +	eval <"$TEST_DIRECTORY/stdin-garbage" >&3 2>&4 "$*"

How about /dev/urandom on platforms that support it?  It wouldn't be
as pleasant to debug as "This is a magic stdin garbage stream", but it
would be more likely to (despite the name :)) predictably trip errors,
or at least hangs, in problematic tests.

With or without something along those lines on top, your patch looks
like a good change.

Thanks for a thoughtful analysis.
Jonathan