Attempt to explicitly terminate our singletons.

This ensures that any global objects are *definitely* cleaned
and freeds when the process terminates.

The intention is that this will allow real leaks to be detected
more easily, via valgrind.

This updates #287.

src/global_state.h

@@ -50,7 +50,7 @@ class CGlobalState : public Singleton<CGlobalState>, public Observer
     /**
      * Destructor.
      */
-    ~CGlobalState();
+    virtual ~CGlobalState();
 
 public:
 

src/lua.h

@@ -52,7 +52,7 @@ class CLua : public Singleton<CLua>, public Observer
 
 public:
     CLua();
-    ~CLua();
+    virtual ~CLua();
 
 public:
 

src/lumail2.cc

@@ -24,12 +24,17 @@
 #include "config.h"
 #include "file.h"
 #include "global_state.h"
+#include "history.h"
 #include "imap_proxy.h"
+#include "input_queue.h"
+#include "logger.h"
 #include "lua.h"
 #include "maildir.h"
 #include "message.h"
 #include "message_part.h"
+#include "mime.h"
 #include "screen.h"
+#include "statuspanel.h"
 #include "tests.h"
 
 /*
@@ -252,6 +257,23 @@ int main(int argc, char *argv[])
     CIMAPProxy *proxy = CIMAPProxy::instance();
     proxy->terminate();
 
+    /*
+     * Now we terminate all our singletons in an aim
+     * to explicitly free memory and make leak-detection
+     * simpler.
+     */
+    config->destroy_instance();
+    proxy->destroy_instance();
+
+    CHistory::instance()->destroy_instance();
+    CGlobalState::instance()->destroy_instance();
+    CInputQueue::instance()->destroy_instance();
+    CStatusPanel::instance()->destroy_instance();
+    CScreen::instance()->destroy_instance();
+    CMime::instance()->destroy_instance();
+    CLua::instance()->destroy_instance();
+    CLogger::instance()->destroy_instance();
+
     /*
      * Close GMime.
      */

src/screen.h

@@ -91,7 +91,7 @@ class CScreen : public Singleton<CScreen>, public Observer
     /**
      * Destructor.
      */
-    ~CScreen();
+    virtual ~CScreen();
 
     /**
      * Register a view mode.