[ImageResizer]Fix silent context menu crash (#22503)

Author: jaimecbernardo

src/modules/imageresizer/ImageResizerContextMenu/dllmain.cpp

@@ -79,6 +79,12 @@ class __declspec(uuid("8F491918-259F-451A-950F-8C3EBF4864AF")) ImageResizerConte
 
     IFACEMETHODIMP GetState(_In_opt_ IShellItemArray* selection, _In_ BOOL okToBeSlow, _Out_ EXPCMDSTATE* cmdState)
     {
+        if (nullptr == selection) {
+            // We've observed that it's possible that a null gets passed instead of an empty array. Just don't show the context menu in this case.
+            *cmdState = ECS_HIDDEN;
+            return S_OK;
+        }
+
         if (!CSettingsInstance().GetEnabled())
         {
             *cmdState = ECS_HIDDEN;
@@ -90,9 +96,14 @@ class __declspec(uuid("8F491918-259F-451A-950F-8C3EBF4864AF")) ImageResizerConte
 #pragma warning(suppress : 26812)
         PERCEIVED type;
         PERCEIVEDFLAG flag;
-        IShellItem* shellItem;
+        IShellItem* shellItem=nullptr;
         //Check extension of first item in the list (the item which is right-clicked on)
-        selection->GetItemAt(0, &shellItem);
+        HRESULT getItemResult  = selection->GetItemAt(0, &shellItem);
+        if (S_OK != getItemResult || nullptr == shellItem) {
+            // Some safeguards to avoid runtime errors.
+            *cmdState = ECS_HIDDEN;
+            return S_OK;
+        }
         LPTSTR pszPath;
         // Retrieves the entire file system path of the file from its shell item
         shellItem->GetDisplayName(SIGDN_FILESYSPATH, &pszPath);