From 31d645bc1e45ae28dfea5d4bd9da78067a32f070 Mon Sep 17 00:00:00 2001
From: KWSys Upstream <kwrobot@kitware.com>
Date: Mon, 28 Sep 2026 08:21:02 -0400
Subject: [PATCH] KWSys 2026-09-28 (9fb826eb)

Code extracted from:

    https://gitlab.kitware.com/utils/kwsys.git

at commit 9fb826ebca7d73ea64a94b8e8ec86cc3b6841b1b (master).

Upstream Shortlog
-----------------

Michael Pratt (1):
      2c678e28 Process: Continue to ignore hangups if SIGHUP is ignored
---
 ProcessUNIX.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/ProcessUNIX.c b/ProcessUNIX.c
index 3f1e0fa2a2..214bc305f6 100644
--- a/ProcessUNIX.c
+++ b/ProcessUNIX.c
@@ -2339,14 +2339,20 @@ static void kwsysProcessChildErrorExit(int errorPipe)
 }
 
 /* Restores all signal handlers to their default values.  */
+/* However, preserve SIGHUP if ignored, e.g. using nohup. */
 static void kwsysProcessRestoreDefaultSignalHandlers(void)
 {
   struct sigaction act;
+#ifdef SIGHUP
+  sigaction(SIGHUP, 0, &act);
+  if (act.sa_handler != SIG_IGN) {
+    memset(&act, 0, sizeof(struct sigaction));
+    act.sa_handler = SIG_DFL;
+    sigaction(SIGHUP, &act, 0);
+  }
+#endif
   memset(&act, 0, sizeof(struct sigaction));
   act.sa_handler = SIG_DFL;
-#ifdef SIGHUP
-  sigaction(SIGHUP, &act, 0);
-#endif
 #ifdef SIGINT
   sigaction(SIGINT, &act, 0);
 #endif