From dc8c382266b056fa51408806478218f5230fbce2 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Thu, 19 Sep 2024 17:23:19 +0900
Subject: [PATCH] Fix bug at fork on FreeBSD

The main thread in a forked process appears not to own the read-write
lock.
---
 process.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/process.c b/process.c
index 1bfa12ba91..ef4757ab23 100644
--- a/process.c
+++ b/process.c
@@ -4234,7 +4234,13 @@ rb_fork_ruby(int *status)
         child.error = err = errno;
 
         disable_child_handler_fork_parent(&old); /* yes, bad name */
-        rb_thread_release_fork_lock();
+        if (
+#if defined(__FreeBSD__)
+            pid != 0 &&
+#endif
+            true) {
+            rb_thread_release_fork_lock();
+        }
         if (pid == 0) {
             rb_thread_reset_fork_lock();
         }