From 3e8007b0557ffa6f10c75a21e9a16f9c5f919ad6 Mon Sep 17 00:00:00 2001
From: Vitaly Novichkov <admin@wohlnet.ru>
Date: Sun, 18 Aug 2019 21:19:56 +0300
Subject: [PATCH] MusPlay: Single-application fix

---
 .../SingleApplication/singleapplication.cpp   | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/examples/MusPlay-Qt/SingleApplication/singleapplication.cpp b/examples/MusPlay-Qt/SingleApplication/singleapplication.cpp
index 1be086af..8154242e 100644
--- a/examples/MusPlay-Qt/SingleApplication/singleapplication.cpp
+++ b/examples/MusPlay-Qt/SingleApplication/singleapplication.cpp
@@ -35,19 +35,22 @@ SingleApplication::SingleApplication(QStringList &args) :
     _shouldContinue = false; // By default this is not the main process
 
     socket = new QUdpSocket();
-    server = NULL;
+    server = nullptr;
     QString isServerRuns;
 
     bool isRunning=false;
     m_sema.acquire();//Avoid races
-    if(m_shmem.attach()) //Detect shared memory copy
-    {
-        isRunning = true;
-    }
-    else
+
+    if(!m_shmem.create(1))//Detect shared memory copy
     {
-        m_shmem.create(1);
-        isRunning = false;
+        m_shmem.attach();
+        m_shmem.detach();
+        if(!m_shmem.create(1))
+        {
+            isRunning = true;
+            if(!m_shmem.attach())
+                qWarning() << "Can't re-attach existing shared memory!";
+        }
     }
 
     //Force run second copy of application