Simple patch for keepassx to minimize to tray on window close rather than exit. For some reason the developer insists that this is a bad pattern, but at least the change is very simple. I'm not claiming this is the best way, some of the conditionals I'm removing should likely stay but this works fine.

keepassx-2.0.3-minimize_on_close.patch

--- keepassx-2.0.3/src/gui/MainWindow.cpp	2017-11-11 09:36:25.000000000 -0500
+++ keepassx-2.0.3-fixed/src/gui/MainWindow.cpp	2017-11-11 09:51:22.898728108 -0500
@@ -441,19 +441,20 @@
 
     if (accept) {
 
-        if ((event->type() == QEvent::WindowStateChange) && isMinimized()
-        && isTrayIconEnabled() && m_trayIcon && m_trayIcon->isVisible()
+        if (isTrayIconEnabled() && m_trayIcon && m_trayIcon->isVisible()
         && config()->get("GUI/MinimizeToTray").toBool())
         {
             event->ignore();
             QTimer::singleShot(0, this, SLOT(hide()));
         }
-        
-/*        saveWindowInformation();
+        else
+        {
+            saveWindowInformation();
 
-        event->accept();
-        QApplication::quit();
-*/    }
+            event->accept();
+            QApplication::quit();
+        }
+    }
     else {
         event->ignore();
     }