From 4b068b7fcbde868ffb4453082522b771580f5e85 Mon Sep 17 00:00:00 2001
From: Vladislav Vaintroub <vvaintroub@gmail.com>
Date: Mon, 28 Oct 2024 10:45:50 +0100
Subject: [PATCH] MDEV-32387 - prevent output during temporary changes to
 STDOUT/STDERR

create_process() temporarily changes STDOUT/STDERR output to error log file

This might redirect mtr output on Windows, so avoid it by holding
flush_lock.
---
 mysql-test/lib/My/SafeProcess/Base.pm | 4 ++++
 mysql-test/lib/mtr_report.pm          | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/mysql-test/lib/My/SafeProcess/Base.pm b/mysql-test/lib/My/SafeProcess/Base.pm
index 1cd01cb0ca9..91ebdc8fe11 100644
--- a/mysql-test/lib/My/SafeProcess/Base.pm
+++ b/mysql-test/lib/My/SafeProcess/Base.pm
@@ -114,6 +114,10 @@ sub create_process {
 
     lock($win32_spawn_lock);
 
+    # STDOUT/STDERR are temporarily reassigned, avoid prevent
+    # output from another thread
+    lock($mtr_report::flush_lock);
+
     #printf STDERR "stdin %d, stdout %d, stderr %d\n",
     #    fileno STDIN, fileno STDOUT, fileno STDERR;
 
diff --git a/mysql-test/lib/mtr_report.pm b/mysql-test/lib/mtr_report.pm
index 0c3c45f3b18..308dbb77a3e 100644
--- a/mysql-test/lib/mtr_report.pm
+++ b/mysql-test/lib/mtr_report.pm
@@ -88,7 +88,7 @@ sub flush_out {
 }
 
 use if $^O eq "MSWin32", "threads::shared";
-my $flush_lock :shared;
+our $flush_lock :shared;
 
 # Print to stdout
 sub print_out {