[PATCH] t: handle EOF in test_copy_bytes()

The test_copy_bytes() function claims to read up to N bytes,
or until it gets EOF. But we never handle EOF in our loop,
and a short input will cause perl to go into an infinite
loop of read() getting zero bytes.

Signed-off-by: Jeff King <redacted>
---
I was playing with SANITIZE=undefined after René's patches to see how
far we had left to go. I forgot to turn off sha1dc, which causes most
programs to die due to the unaligned loads. That means git-archive in
t5000 generates no output, triggering the bug. :)

 t/test-lib-functions.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index db622c355..50a9a1d1c 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh

@@ -999,6 +999,7 @@ test_copy_bytes () {
 			my $s;
 			my $nread = sysread(STDIN, $s, $len);
 			die "cannot read: $!" unless defined($nread);
+			last unless $nread;
 			print $s;
 			$len -= $nread;
 		}

-- 
2.14.0.rc0.452.gc10560834