From 8166bfc7b823242c87b17cb62fac015e5720fa3c Mon Sep 17 00:00:00 2001
From: Maksim Derbasov <ntfs.hard@gmail.com>
Date: Wed, 9 Aug 2023 17:26:46 +0900
Subject: [PATCH] Do not crash on GUI shutdown (#5288)

Seems current code for worker threads termination is too brutal which
leads to crash on termination:
```
QThread::start: Thread termination error: No such process
Segmentation fault (core dumped)
```
Seems better to use `quit()` and `wait()`, like in an example:
https://doc.qt.io/qt-6/qthread.html#details

tested: Ubuntu Linux 20
---
 gui/checkthread.h     | 6 ++++--
 gui/threadhandler.cpp | 5 ++++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/gui/checkthread.h b/gui/checkthread.h
index 9a1fea3e6..d74ec2514 100644
--- a/gui/checkthread.h
+++ b/gui/checkthread.h
@@ -24,6 +24,8 @@
 #include "importproject.h"
 #include "suppressions.h"
 
+#include <atomic>
+
 #include <QList>
 #include <QObject>
 #include <QString>
@@ -118,9 +120,9 @@ protected:
     };
 
     /**
-     * @brief Thread's current execution state.
+     * @brief Thread's current execution state. Can be changed from outside
      */
-    State mState = Ready;
+    std::atomic<State> mState{Ready};
 
     ThreadResult &mResult;
     /**
diff --git a/gui/threadhandler.cpp b/gui/threadhandler.cpp
index 43faf2aea..6e99afe04 100644
--- a/gui/threadhandler.cpp
+++ b/gui/threadhandler.cpp
@@ -148,7 +148,10 @@ void ThreadHandler::setThreadCount(const int count)
 void ThreadHandler::removeThreads()
 {
     for (CheckThread* thread : mThreads) {
-        thread->terminate();
+        if (thread->isRunning()) {
+            thread->terminate();
+            thread->wait();
+        }
         disconnect(thread, &CheckThread::done,
                    this, &ThreadHandler::threadDone);
         disconnect(thread, &CheckThread::fileChecked,