Fix intermittent test failure in 80-test_cmp_http.t

output to stderr is unbuffered bypassing the normal output, which does
not happen at line boundaries and is therefore confusing the TAP parser.
This is known to cause random test failures like this one:

80-test_cmp_http.t                    (Wstat: 0 Tests: 5 Failed: 0)
  Parse errors: Tests out of sequence.  Found (6) but expected (5)
                Bad plan.  You planned 6 tests but ran 5.

Fixes #23992

Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/26364)

(cherry picked from commit 9e362d7a9da3677015646bd7b3d8a7ef4e8e8ec9)

diff --git a/test/recipes/80-test_cmp_http.t b/test/recipes/80-test_cmp_http.t
index 0ca547354fc7e39b4be03f07203305fb5eea5681..e4199caa2dfff77cd7f406f12c517d69b4697f58 100644 (file)
--- a/test/recipes/80-test_cmp_http.t
+++ b/test/recipes/80-test_cmp_http.t
@@ -270,7 +270,7 @@ sub start_mock_server {
     print "Current directory is ".getcwd()."\n";
     print "Launching mock server: $cmd\n";
     die "Invalid port: $server_port" unless $server_port =~ m/^\d+$/;
-    my $pid = open($server_fh, "$cmd|") or die "Trying to $cmd";
+    my $pid = open($server_fh, "$cmd 2>".result_dir()."/error.txt |") or die "Trying to $cmd";
     print "Pid is: $pid\n";
     if ($server_port == 0) {
         # Find out the actual server port