From 21bdef01eddcbd78044eea1d50b9dee08d218ff2 Mon Sep 17 00:00:00 2001
From: Adam Treat <treat.adam@gmail.com>
Date: Thu, 29 Aug 2024 12:45:45 -0400
Subject: [PATCH] Check the primary connection and assume primary if no
 response is found.

This guards against the case of stale shared memory that can happen when
the primary application crashes or is forcefully killed.

Issue #190

Signed-off-by: Adam Treat <treat.adam@gmail.com>
---
 singleapplication.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/singleapplication.cpp b/singleapplication.cpp
index 95c4d18..d676871 100644
--- a/singleapplication.cpp
+++ b/singleapplication.cpp
@@ -137,6 +137,13 @@ SingleApplication::SingleApplication( int &argc, char *argv[], bool allowSeconda
       }
     }
 
+    // Check to ensure the primary process really does exist by sending a message and if it does not
+    // then assume primary status
+    if ( inst->primary != false && !d->connectToPrimary( timeout, SingleApplicationPrivate::SecondaryInstance )) {
+          qDebug() << "SingleApplication: Cannot communicate with primary so assuming primary status.";
+          inst->primary = false;
+    }
+
     if( inst->primary == false ){
         d->startPrimary();
         if( ! d->memory->unlock() ){