From 034d755f2f21088b97fdb0a34d846c39fcdbf46d Mon Sep 17 00:00:00 2001
From: Eli Zaretskii <eliz@gnu.org>
Date: Sat, 16 Aug 2025 13:28:52 +0300
Subject: [PATCH] ; * src/process.c (set_proc_thread): Fix assertion.

---
 src/process.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/process.c b/src/process.c
index f8d67561f26..c8b70a4174c 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1449,7 +1449,8 @@ See `set-process-sentinel' for more info on sentinels.  */)
 static void
 set_proc_thread (struct Lisp_Process *proc, struct thread_state *thrd)
 {
-  eassert (THREADP (proc->thread) && XTHREAD (proc->thread) == thrd);
+  eassert ((NILP (proc->thread) && !thrd)
+	   || (THREADP (proc->thread) && XTHREAD (proc->thread) == thrd));
   eassert (proc->infd < FD_SETSIZE);
   if (proc->infd >= 0)
     fd_callback_info[proc->infd].thread = thrd;