Re: tr/pty-all (Re: What's cooking in git.git (Dec 2011, #04; Tue, 13))

On Wed, Dec 14, 2011 at 05:31:19PM -0600, Jonathan Nieder wrote:

quoted

@@ -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.

I'd rather have something deterministic. If you really want to be mean
to accidental readers of stdin, then put binary junk into stdin-garbage
(even the results of a single run of /dev/urandom, if you like). But I
suspect arbitrary text is good enough to throw a monkey wrench into
anything that will care about its input (and those that don't are beyond
our ability to auto-detect anyway[1]). And it's way easier to debug than
seeing random binary bits.

-Peff

[1] Actually, you could abandon the idea of feeding garbage altogether,
and instead open the descriptor outside the test, then check that its
offset is still 0 after the test. You'd have to use a helper program to
do the ftell(), but it should work as the descriptor position will be
shared.