[EXPLORER] Fix handle leaks (reactos#8516)

JIRA issue: CORE-15616
JIRA issue: CORE-14382

The Explorer shell has multiple resource leaks causing handle exhaustion over extended use.

Author: Copilot

base/shell/explorer/syspager.cpp

@@ -168,13 +168,15 @@ class CNotifyToolbar :
     void RefreshToolbarMetrics(BOOL bForceRefresh);
 
 private:
+    LRESULT OnDestroy(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled);
     LRESULT OnCtxMenu(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled);
     VOID SendMouseEvent(IN WORD wIndex, IN UINT uMsg, IN WPARAM wParam);
     LRESULT OnMouseEvent(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled);
     LRESULT OnTooltipShow(INT uCode, LPNMHDR hdr, BOOL& bHandled);
 
 public:
     BEGIN_MSG_MAP(CNotifyToolbar)
+        MESSAGE_HANDLER(WM_DESTROY, OnDestroy)
         MESSAGE_HANDLER(WM_CONTEXTMENU, OnCtxMenu)
         MESSAGE_RANGE_HANDLER(WM_MOUSEFIRST, WM_MOUSELAST, OnMouseEvent)
         NOTIFY_CODE_HANDLER(TTN_SHOW, OnTooltipShow)
@@ -1031,6 +1033,17 @@ VOID CNotifyToolbar::ResizeImagelist()
     SetButtonSize(GetSystemMetrics(SM_CXSMICON), GetSystemMetrics(SM_CYSMICON));
 }
 
+LRESULT CNotifyToolbar::OnDestroy(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
+{
+    if (m_ImageList)
+    {
+        ImageList_Destroy(m_ImageList);
+        m_ImageList = NULL;
+    }
+    
+    return 0;
+}
+
 LRESULT CNotifyToolbar::OnCtxMenu(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
 {
     bHandled = FALSE;

base/shell/explorer/taskswnd.cpp

@@ -276,7 +276,6 @@ class CHardErrorThread
         if (!m_hThread)
         {
             m_bThreadRunning = FALSE;
-            CloseHandle(m_hThread);
         }
     }
 };
@@ -1557,6 +1556,13 @@ class CTaskSwitchWnd :
 
         CloseThemeData(m_Theme);
         DeleteAllTasks();
+
+        if (m_ImageList)
+        {
+            ImageList_Destroy(m_ImageList);
+            m_ImageList = NULL;
+        }
+
         return TRUE;
     }
 

base/shell/explorer/traywnd.cpp

@@ -533,7 +533,9 @@ class CTrayWindow :
             }
         }
 
-        CloseHandle(CreateThread(NULL, 0, s_RunFileDlgThread, this, 0, NULL));
+        HANDLE hThread = CreateThread(NULL, 0, s_RunFileDlgThread, this, 0, NULL);
+        if (hThread)
+            CloseHandle(hThread);
     }
 
     DWORD WINAPI TrayPropertiesThread()
@@ -587,7 +589,9 @@ class CTrayWindow :
             }
         }
 
-        CloseHandle(CreateThread(NULL, 0, s_TrayPropertiesThread, this, 0, NULL));
+        HANDLE hThread = CreateThread(NULL, 0, s_TrayPropertiesThread, this, 0, NULL);
+        if (hThread)
+            CloseHandle(hThread);
         return NULL;
     }