From c9fa54536e7f8d58dd94c5f4d5b92b1e82a5f3b1 Mon Sep 17 00:00:00 2001
From: Paul Swirhun <63216497+paul-demo@users.noreply.github.com>
Date: Mon, 26 May 2025 05:58:20 -0700
Subject: [PATCH] Tests: Fix MacOS test driver when child process finishes
 (#6032) (#6038)

os.read(fd, 1) returns b'' on MacOS when the
child process exits, whereas it must be throwing an OSError
on other platforms.
---
 test_regress/driver.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test_regress/driver.py b/test_regress/driver.py
index cd49c6d8f..fd766c7b3 100755
--- a/test_regress/driver.py
+++ b/test_regress/driver.py
@@ -1734,6 +1734,9 @@ class VlTest:
                     try:
                         data = os.read(fd, 1)
                         self._run_output(data, logfh, tee)
+                        # Parent detects child termination by checking for b''
+                        if not data:
+                            break
                     except OSError:
                         break