Bug 1678580 - Check file picker result for errors before showing ConfirmFolderUpload prompt. r=baku

Differential Revision: https://phabricator.services.mozilla.com/D97755

dom/html/HTMLInputElement.cpp

@@ -484,6 +484,7 @@ HTMLInputElement::nsFilePickerShownCallback::Done(int16_t aResult) {
                mode == static_cast<int16_t>(nsIFilePicker::modeGetFolder));
     nsCOMPtr<nsISupports> tmp;
     nsresult rv = mFilePicker->GetDomFileOrDirectory(getter_AddRefs(tmp));
+    NS_ENSURE_SUCCESS(rv, rv);
 
     // Show a prompt to get user confirmation before allowing folder access.
     // This is to prevent sites from tricking the user into uploading files.
@@ -515,8 +516,6 @@ HTMLInputElement::nsFilePickerShownCallback::Done(int16_t aResult) {
       }
     }
 
-    NS_ENSURE_SUCCESS(rv, rv);
-
     RefPtr<Blob> blob = do_QueryObject(tmp);
     if (blob) {
       RefPtr<File> file = blob->ToFile();