Issue #3391 - Initialize themed drawing variables using DetachedInitializer

src/plugin/PluginClass.cpp

Index: src/plugin/PluginClass.cpp
===================================================================
--- a/src/plugin/PluginClass.cpp
+++ b/src/plugin/PluginClass.cpp
@@ -39,9 +39,16 @@
 
 extern CComModule _Module;
 
-typedef HANDLE (WINAPI *OPENTHEMEDATA)(HWND, LPCWSTR);
-typedef HRESULT (WINAPI *DRAWTHEMEBACKGROUND)(HANDLE, HDC, INT, INT, LPRECT, LPRECT);
-typedef HRESULT (WINAPI *CLOSETHEMEDATA)(HANDLE);
+namespace
+{
+  typedef HANDLE (WINAPI *OPENTHEMEDATA)(HWND, LPCWSTR);
+  typedef HRESULT (WINAPI *DRAWTHEMEBACKGROUND)(HANDLE, HDC, INT, INT, LPRECT, LPRECT);
+  typedef HRESULT (WINAPI *CLOSETHEMEDATA)(HANDLE);
+
+  CLOSETHEMEDATA pfnClose = NULL;
+  DRAWTHEMEBACKGROUND pfnDrawThemeBackground = NULL;
+  OPENTHEMEDATA pfnOpenThemeData = NULL;
+}
 
 HICON CPluginClass::s_hIcons[ICON_MAX] = { NULL, NULL, NULL };
 DWORD CPluginClass::s_hIconTypes[ICON_MAX] = { IDI_ICON_DISABLED, IDI_ICON_ENABLED, IDI_ICON_DEACTIVATED };
@@ -49,20 +56,14 @@
 uint32_t iconWidth = 32;
 
 CPluginMimeFilterClient* CPluginClass::s_mimeFilter = NULL;
-
-CLOSETHEMEDATA pfnClose = NULL;
-DRAWTHEMEBACKGROUND pfnDrawThemeBackground = NULL;
-OPENTHEMEDATA pfnOpenThemeData = NULL;
-
 ATOM CPluginClass::s_atomPaneClass = NULL;
-HINSTANCE CPluginClass::s_hUxtheme = NULL;
 std::set<CPluginClass*> CPluginClass::s_instances;
 std::map<DWORD, CPluginClass*> CPluginClass::s_threadInstances;
-
 CComAutoCriticalSection CPluginClass::s_criticalSectionLocal;
 CComAutoCriticalSection CPluginClass::s_criticalSectionWindow;
+CComQIPtr<IWebBrowser2> CPluginClass::s_asyncWebBrowser2;
+CPluginClass::DetachedInitializerType CPluginClass::di;
 
-CComQIPtr<IWebBrowser2> CPluginClass::s_asyncWebBrowser2;
 
 /*
  * Without namespace declaration, the identifier "Rectangle" is ambiguous
@@ -103,11 +104,9 @@
   m_pWndProcStatus = NULL;
   m_hTheme = NULL;
   m_isInitializedOk = false;
-
-
   m_tab = new CPluginTab(this);
-
   Dictionary::Create(GetBrowserLanguage());
+  di.SpawnInitializer();
 }
 
 CPluginClass::~CPluginClass()
@@ -115,6 +114,50 @@
   delete m_tab;
 }
 
+/*
+ * Because this initialization function does not throw, neither can EnsureInitialized().
+ */
+void CPluginClass::Initializer() // noexcept
+{
+  try
+  {
+    /*
+     * Initializes these static, anonymous-namespace variables
+     *   - pfnClose
+     *   - pfnDrawThemeBackground
+     *   - pfnOpenThemeData
+     */
+    HINSTANCE UxthemeModule = ::GetModuleHandle(L"uxtheme.dll");
+    if (!UxthemeModule)
+    {
+      DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_UI, PLUGIN_ERROR_UI_GET_UXTHEME, "CPluginClass::Initializer - GetModuleHandle(uxtheme.dll)");
+    }
+    else
+    {
+      pfnClose = (CLOSETHEMEDATA)::GetProcAddress(UxthemeModule, "CloseThemeData");
+      if (!pfnClose)
+      {
+        DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_UI, PLUGIN_ERROR_UI_GET_UXTHEME_CLOSE, "CPluginClass::Initializer - GetProcAddress(CloseThemeData)");
+      }
+      pfnDrawThemeBackground = (DRAWTHEMEBACKGROUND)::GetProcAddress(UxthemeModule, "DrawThemeBackground");
+      if (!pfnDrawThemeBackground)
+      {
+        DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_UI, PLUGIN_ERROR_UI_GET_UXTHEME_DRAW_BACKGROUND, "CPluginClass::Initializer - GetProcAddress(DrawThemeBackground)");
+      }
+      pfnOpenThemeData = (OPENTHEMEDATA)::GetProcAddress(UxthemeModule, "OpenThemeData");
+      if (!pfnOpenThemeData)
+      {
+        DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_UI, PLUGIN_ERROR_UI_GET_UXTHEME_OPEN, "CPluginClass::Initializer - GetProcAddress(pfnOpenThemeData)");
+      }
+    }
+  }
+  catch (...)
+  {
+    // Suppress all exceptions
+  }
+}
+
+
 HWND CPluginClass::GetBrowserHWND() const
 {
   if (!m_webBrowser2)
@@ -596,40 +639,6 @@
     s_mimeFilter->Unregister();
   }
 
-  // Load theme module
-  s_criticalSectionLocal.Lock();
-  {
-    if (!s_hUxtheme)
-    {
-      s_hUxtheme = ::GetModuleHandle(L"uxtheme.dll");
-      if (s_hUxtheme)
-      {
-        pfnClose = (CLOSETHEMEDATA)::GetProcAddress(s_hUxtheme, "CloseThemeData");
-        if (!pfnClose)
-        {
-          DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_UI, PLUGIN_ERROR_UI_GET_UXTHEME_CLOSE, "Class::InitObject - GetProcAddress(CloseThemeData)");
-        }
-
-        pfnDrawThemeBackground = (DRAWTHEMEBACKGROUND)::GetProcAddress(s_hUxtheme, "DrawThemeBackground");
-        if (!pfnDrawThemeBackground)
-        {
-          DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_UI, PLUGIN_ERROR_UI_GET_UXTHEME_DRAW_BACKGROUND, "Class::InitObject - GetProcAddress(DrawThemeBackground)");
-        }
-
-        pfnOpenThemeData = (OPENTHEMEDATA)::GetProcAddress(s_hUxtheme, "OpenThemeData");
-        if (!pfnOpenThemeData)
-        {
-          DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_UI, PLUGIN_ERROR_UI_GET_UXTHEME_OPEN, "Class::InitObject - GetProcAddress(pfnOpenThemeData)");
-        }
-      }
-      else
-      {
-        DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_UI, PLUGIN_ERROR_UI_GET_UXTHEME, "Class::InitObject - GetModuleHandle(uxtheme.dll)");
-      }
-    }
-  }
-  s_criticalSectionLocal.Unlock();
-
   // Register pane class
   if (!GetAtomPaneClass())
   {
@@ -902,29 +911,21 @@
     DEBUG_ERROR_LOG(hr, PLUGIN_ERROR_NAVIGATION, PLUGIN_ERROR_NAVIGATION_WELCOME, "Navigation::Welcome page failed")
   }
 }
-void CPluginClass::CloseTheme()
+
+void CPluginClass::UpdateTheme()
 {
+  EnsureInitialized(); // pfnClose, pfnOpenThemeData
   if (m_hTheme)
   {
     if (pfnClose)
     {
       pfnClose(m_hTheme);
     }
-
     m_hTheme = NULL;
   }
-}
-
-void CPluginClass::UpdateTheme()
-{
-  CloseTheme();
-
   if (pfnOpenThemeData)
   {
     m_hTheme = pfnOpenThemeData(m_hPaneWnd, L"STATUS");
-    if (!m_hTheme)
-    {
-    }
   }
 }
 
@@ -1413,6 +1414,7 @@
       else
       {
         // Draw background
+        EnsureInitialized(); // pfnDrawThemeBackground
         if (pfnDrawThemeBackground)
         {
           AdblockPlus::Rectangle rc = rcClient;