From e05abf16b5350e7ef2daf5d1a2fc283ca101e3c7 Mon Sep 17 00:00:00 2001
From: "andrey.bychkov" <andrey@signalmodelling.ru>
Date: Wed, 5 Aug 2026 17:38:07 +0300
Subject: [PATCH] fix(PIWaitEvent): use -1 as pipe_fd sentinel instead of 0

File descriptor 0 is stdin (a valid fd). Using 0 as the 'not-open'
sentinel caused isCreate() to return false and destroy() to skip
close() when pipe() happened to allocate fds {0, 1} (e.g. in daemons
with closed stdio). POSIX convention: -1 = invalid fd.
---
 libs/main/core/piwaitevent_p.cpp | 6 +++---
 libs/main/core/piwaitevent_p.h   | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/libs/main/core/piwaitevent_p.cpp b/libs/main/core/piwaitevent_p.cpp
index 47983a5d..36ec80bc 100644
--- a/libs/main/core/piwaitevent_p.cpp
+++ b/libs/main/core/piwaitevent_p.cpp
@@ -65,9 +65,9 @@ void PIWaitEvent::destroy() {
 	}
 #else
 	for (int i = 0; i < 2; ++i) {
-		if (pipe_fd[i] != 0) {
+		if (pipe_fd[i] != -1) {
 			::close(pipe_fd[i]);
-			pipe_fd[i] = 0;
+			pipe_fd[i] = -1;
 		}
 	}
 #endif
@@ -140,7 +140,7 @@ bool PIWaitEvent::isCreate() const {
 #ifdef WINDOWS
 	return event;
 #else
-	return pipe_fd[ReadEnd] != 0;
+	return pipe_fd[ReadEnd] != -1;
 #endif
 }
 
diff --git a/libs/main/core/piwaitevent_p.h b/libs/main/core/piwaitevent_p.h
index 9814d449..1af19ac1 100644
--- a/libs/main/core/piwaitevent_p.h
+++ b/libs/main/core/piwaitevent_p.h
@@ -55,7 +55,7 @@ private:
 #ifdef WINDOWS
 	void * event = nullptr;
 #else
-	int pipe_fd[2] = {0, 0};
+	int pipe_fd[2] = {-1, -1};
 	fd_set fds[3];
 	enum {
 		ReadEnd  = 0,