From: Jeff King <peff@peff.net>
Date: Sat, 25 Jul 2026 10:10:43 GMT
Subject: Re: [PATCH v3 0/3] packfile URIs: support concurrent downloads
Message-ID: <20260725101043.GA2171844@coredump.intra.peff.net>
In-Reply-To: <20260725100251.GA1933232@coredump.intra.peff.net>

On Sat, Jul 25, 2026 at 06:02:51AM -0400, Jeff King wrote:

> I wonder if we could just drop that "test -s" entirely. We'd _usually_
> see some bytes written before the second request starts. But it's OK if
> we don't. It just means the test is working in the reverse order (the
> second request may write its bytes first, and then the first one is the
> one "overwriting" it). I.e., the two are symmetric from our perspective.

Yeah, doing this:

diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index dcb9667eeb..07aa218049 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -516,7 +516,6 @@ test_expect_success PERL,PIPE 'concurrent http-fetch --packfile cannot corrupt a
 	read ready <&8 &&
 	test "$ready" = ready &&
 	test_path_is_file "$tmpfile" &&
-	test -s "$tmpfile" &&
 	{
 		GIT_TRACE_CURL="$TRASH_DIRECTORY/overlap-second.trace" \
 		GIT_TRACE_CURL_NO_DATA=1 \
@@ -533,9 +532,6 @@ test_expect_success PERL,PIPE 'concurrent http-fetch --packfile cannot corrupt a
 	wait "$second_pid" &&
 	wait "$first_pid" &&
 	wait "$server_pid" &&
-	test_grep "HTTP/[0-9.]* 200" overlap-first.trace &&
-	test_grep "Range: bytes=[1-9][0-9]*-" overlap-second.trace &&
-	test_grep "HTTP/[0-9.]* 206" overlap-second.trace &&
 	printf "keep\t%s\npack\t%s\n" "$packhash" "$packhash" | sort >expect &&
 	sort first.out second.out >actual &&
 	test_cmp expect actual &&

is enough to make it pass reliably under --stress for me. We have to
drop the trace greps, because we don't actually know whether each
request will use a range or not. We'd _usually_ see a range for the
second one, but it's possible it might still see a zero-byte file. I
guess we probably see a "200" reliably for the first request, but it's
not all that interesting.

We can leave the test_path_is_file check, because we open the file
before making the request (it is only the actual writing of bytes that
is racy).

-Peff