From 93ea04b912a90e6a166941c575b4da128e3b7533 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 13 Jan 2025 09:27:28 -0600
Subject: [PATCH v1 1/1] modify pqsignal

---
 src/include/port.h  |  2 +-
 src/port/pqsignal.c | 32 ++++++--------------------------
 2 files changed, 7 insertions(+), 27 deletions(-)

diff --git a/src/include/port.h b/src/include/port.h
index f0e28ce5c53..4e9e5657872 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -520,7 +520,7 @@ extern int	pg_mkdir_p(char *path, int omode);
 #define pqsignal pqsignal_be
 #endif
 typedef void (*pqsigfunc) (SIGNAL_ARGS);
-extern pqsigfunc pqsignal(int signo, pqsigfunc func);
+extern void pqsignal(int signo, pqsigfunc func);
 
 /* port/quotes.c */
 extern char *escape_single_quotes_ascii(const char *src);
diff --git a/src/port/pqsignal.c b/src/port/pqsignal.c
index f707b1c54e1..076e3dfe340 100644
--- a/src/port/pqsignal.c
+++ b/src/port/pqsignal.c
@@ -114,29 +114,15 @@ wrapper_handler(SIGNAL_ARGS)
  *
  * Returns the previous handler.
  *
- * NB: If called within a signal handler, race conditions may lead to bogus
- * return values.  You should either avoid calling this within signal handlers
- * or ignore the return value.
- *
- * XXX: Since no in-tree callers use the return value, and there is little
- * reason to do so, it would be nice if we could convert this to a void
- * function instead of providing potentially-bogus return values.
- * Unfortunately, that requires modifying the pqsignal() in legacy-pqsignal.c,
- * which in turn requires an SONAME bump, which is probably not worth it.
- *
  * Note: the actual name of this function is either pqsignal_fe when
  * compiled with -DFRONTEND, or pqsignal_be when compiled without.
  * This is to avoid a name collision with libpq's legacy-pqsignal.c.
  */
-pqsigfunc
+void
 pqsignal(int signo, pqsigfunc func)
 {
-	pqsigfunc	orig_func = pqsignal_handlers[signo];	/* assumed atomic */
 #if !(defined(WIN32) && defined(FRONTEND))
-	struct sigaction act,
-				oact;
-#else
-	pqsigfunc	ret;
+	struct sigaction act;
 #endif
 
 	Assert(signo < PG_NSIG);
@@ -155,17 +141,11 @@ pqsignal(int signo, pqsigfunc func)
 	if (signo == SIGCHLD)
 		act.sa_flags |= SA_NOCLDSTOP;
 #endif
-	if (sigaction(signo, &act, &oact) < 0)
-		return SIG_ERR;
-	else if (oact.sa_handler == wrapper_handler)
-		return orig_func;
-	else
-		return oact.sa_handler;
+	if (sigaction(signo, &act, NULL) < 0)
+		Assert(false);			/* probably indicates coding error */
 #else
 	/* Forward to Windows native signal system. */
-	if ((ret = signal(signo, func)) == wrapper_handler)
-		return orig_func;
-	else
-		return ret;
+	if (signal(signo, func) == SIG_ERR)
+		Assert(false);			/* probably indicates coding error */
 #endif
 }
-- 
2.39.5 (Apple Git-154)