From c63594acecf11b2201d4f356701be74b57eb9dff Mon Sep 17 00:00:00 2001
From: James Turner <james@flightgear.org>
Date: Mon, 2 Nov 2020 14:55:35 +0000
Subject: [PATCH] =?UTF-8?q?Launcher:=20abandon=20NautralEarth=20loading=20?=
 =?UTF-8?q?on=20=E2=80=98fly!=E2=80=99?=
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Otherwise we waste time trying to commit loaded data during FG main
startup, which causes races on the NavCache, and is pointless.
---
 src/GUI/QtLauncher.cxx | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/GUI/QtLauncher.cxx b/src/GUI/QtLauncher.cxx
index 7d07d242f..b531fc8dd 100644
--- a/src/GUI/QtLauncher.cxx
+++ b/src/GUI/QtLauncher.cxx
@@ -39,6 +39,7 @@
 #include <QProcess>
 #include <QTranslator>
 #include <QMessageBox>
+#include <QPointer>
 
 // Simgear
 #include <simgear/timing/timestamp.hxx>
@@ -187,6 +188,10 @@ public:
         connect(this, &QThread::finished, this, &NaturalEarthDataLoaderThread::onFinished);
     }
 
+    void abandon()
+    {
+        m_abandoned = true;
+    }
 protected:
     void run() override
     {
@@ -199,6 +204,9 @@ protected:
 private:
     Q_SLOT void onFinished()
     {
+        if (m_abandoned)
+            return;
+
         flightgear::PolyLineList::const_iterator begin = m_parsedLines.begin() + m_lineInsertCount;
         unsigned int numToAdd = std::min<unsigned int>(1000U, static_cast<unsigned int>(m_parsedLines.size()) - m_lineInsertCount);
         flightgear::PolyLineList::const_iterator end = begin + numToAdd;
@@ -228,6 +236,7 @@ private:
 
     flightgear::PolyLineList m_parsedLines;
     unsigned int m_lineInsertCount;
+    bool m_abandoned = false;
 };
 
 } // of anonymous namespace
@@ -511,7 +520,7 @@ bool runLauncherDialog()
     // will happen as normal
     http->init();
 
-    NaturalEarthDataLoaderThread* naturalEarthLoader = new NaturalEarthDataLoaderThread;
+    QPointer<NaturalEarthDataLoaderThread> naturalEarthLoader = new NaturalEarthDataLoaderThread;
     naturalEarthLoader->start();
 
     // avoid double Apple menu and other weirdness if both Qt and OSG
@@ -530,6 +539,12 @@ bool runLauncherDialog()
         return false; // quit
     }
 
+    // avoid crashes / NavCache races if the loader is still running after
+    // the launcher exits
+    if (naturalEarthLoader) {
+        naturalEarthLoader->abandon();
+    }
+
     // avoid a race-y crash on the locale, if a scan thread is
     // still running: this reset will cancel any running scan
     LocalAircraftCache::reset();