Don't write to stdin of a test process that could have already exited.

Instead, close that stdin.  Per buildfarm member conchuela.  Back-patch
to 9.6, where the test was introduced.

Discussion: https://postgr.es/m/26478.1555373328@sss.pgh.pa.us

diff --git a/src/test/recovery/t/017_shm.pl b/src/test/recovery/t/017_shm.pl
index f89d53a8793c0b5dceabc9db7f4888afc5575446..f16821d51fe97d3a0dc53f15f11d8e70d0eed4ea 100644 (file)
--- a/src/test/recovery/t/017_shm.pl
+++ b/src/test/recovery/t/017_shm.pl
@@ -153,7 +153,7 @@ like(slurp_file($gnat->logfile),
 my $single_stderr;
 ok( !run_log(
                [ 'postgres', '--single', '-D', $gnat->data_dir, 'template1' ],
-               '<', \('SELECT 1 + 1'), '2>', \$single_stderr),
+               '<', \undef, '2>', \$single_stderr),
        'live query blocks --single');
 print STDERR $single_stderr;
 like($single_stderr, $pre_existing_msg,