From 422c839ae2d40a0a14a72418091e9e303c708192 Mon Sep 17 00:00:00 2001
From: Thulinma <jaron@vietors.com>
Date: Tue, 23 May 2017 21:21:21 +0200
Subject: [PATCH] Fix semaphore segfault when tryWait'ing on invalid semaphore.

---
 lib/shared_memory.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/shared_memory.cpp b/lib/shared_memory.cpp
index 0f93d803..24421402 100644
--- a/lib/shared_memory.cpp
+++ b/lib/shared_memory.cpp
@@ -222,6 +222,7 @@ namespace IPC {
 
   ///\brief Tries to wait for the semaphore, returns true if successful, false otherwise
   bool semaphore::tryWait() {
+    if (!(*this)){return false;}
     int result;
 #if defined(__CYGWIN__) || defined(_WIN32)
     result = WaitForSingleObject(mySem, 0);//wait at most 1ms
@@ -237,6 +238,7 @@ namespace IPC {
 
   ///\brief Tries to wait for the semaphore for a single second, returns true if successful, false otherwise
   bool semaphore::tryWaitOneSecond() {
+    if (!(*this)){return false;}
     int result;
 #if defined(__CYGWIN__) || defined(_WIN32)
     result = WaitForSingleObject(mySem, 1000);//wait at most 1s