Fix crash on exit: delete postgres connection pool before QApplication

Author: m-kuhn

src/providers/postgres/qgspostgresconnpool.cpp

@@ -16,11 +16,19 @@
 #include "qgspostgresconnpool.h"
 #include "qgspostgresconn.h"
 
-QgsPostgresConnPool QgsPostgresConnPool::sInstance;
+QgsPostgresConnPool* QgsPostgresConnPool::sInstance = nullptr;
 
 QgsPostgresConnPool* QgsPostgresConnPool::instance()
 {
-  return &sInstance;
+  if ( !sInstance )
+    sInstance = new QgsPostgresConnPool();
+  return sInstance;
+}
+
+void QgsPostgresConnPool::cleanupInstance()
+{
+  delete sInstance;
+  sInstance = nullptr;
 }
 
 QgsPostgresConnPool::QgsPostgresConnPool() : QgsConnectionPool<QgsPostgresConn*, QgsPostgresConnPoolGroup>()

src/providers/postgres/qgspostgresconnpool.h

@@ -70,14 +70,16 @@ class QgsPostgresConnPool : public QgsConnectionPool<QgsPostgresConn*, QgsPostgr
   public:
     static QgsPostgresConnPool* instance();
 
+    static void cleanupInstance();
+
   protected:
     Q_DISABLE_COPY( QgsPostgresConnPool )
 
   private:
     QgsPostgresConnPool();
     ~QgsPostgresConnPool();
 
-    static QgsPostgresConnPool sInstance;
+    static QgsPostgresConnPool* sInstance;
 };
 
 

src/providers/postgres/qgspostgresprovider.cpp

@@ -4130,6 +4130,10 @@ QGISEXTERN QgsTransaction* createTransaction( const QString& connString )
   return new QgsPostgresTransaction( connString );
 }
 
+QGISEXTERN void cleanupProvider()
+{
+  QgsPostgresConnPool::cleanupInstance();
+}
 
 // ----------