From efda4f5c39ba24743cb28b2e1b83d7d270bb07aa Mon Sep 17 00:00:00 2001
From: Mahmoud Al-Qudsi <mqudsi@neosmart.net>
Date: Tue, 23 Mar 2021 02:14:20 -0500
Subject: [PATCH] Make zombie test smarter

Instead of trying to assert that there are no zombies when the test
starts (which often fails) and to prevent conflating existing or
irrelevant zombies with the ones we are interested in checking for,
have `ps` also emit the parent process id and filter its output to
include only children of the current fish instance.
---
 tests/checks/jobs.fish | 29 +++++++----------------------
 1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/tests/checks/jobs.fish b/tests/checks/jobs.fish
index 3b591d0a7..08fbb2223 100644
--- a/tests/checks/jobs.fish
+++ b/tests/checks/jobs.fish
@@ -1,22 +1,5 @@
 #RUN: %fish %s
 
-# Ensure there's no zombies before we start, otherwise the tests will mysteriously fail.
-set -l zombies_among_us
-if not contains (uname) SunOS
-    set zombies_among_us (ps -o stat | string match 'Z*' | count)
-else
-    # Solaris' ps is awkward, I don't know if this actually works
-    set zombies_among_us (ps -o s | string match 'Z*' | count)
-end
-
-[ "$zombies_among_us" -eq "0" ]
-or begin
-	echo "Found existing zombie processes. Clean up zombies before running this test."
-	exit 1
-end
-echo "All clear of zombies."
-# CHECK: All clear of zombies.
-
 # Verify zombies are not left by disown (#7183, #5342)
 # Do this first to avoid colliding with the other disowned processes below, which may
 # still be running at the end of the script
@@ -28,13 +11,15 @@ sleep 0.1
 #CHECK: Trigger process reaping
 # The initial approach here was to kill the PID of the sleep process, which should
 # be gone by the time we get here. Unfortunately, kill from procps on pre-2016 distributions
-# does not print an error for non-existent PIDs, so instead look for zombies in this session
-# (there should be none).
+# does not print an error for non-existent PIDs, so instead look for zombies in this session.
+# There could already be zombies from previous tests run in this session or a test could be run
+# simultaneously that causes a zombie to spawn, so limit the output only to processes started by
+# this fish instance.
 if not contains (uname) SunOS
-    ps -o stat | string match 'Z*'
+    ps -o ppid,stat
 else
-    ps -o s | string match 'Z*'
-end
+    ps -o ppid,s
+end | string match -e $fish_pid | string match 'Z*'
 
 # Verify disown can be used with last_pid, even if it is separate from the pgroup.
 # This should silently succeed.