When trying to add a duplicate target to a closed question on my iPhone, I'd like to paste a URL in the box where you're supposed to 'search, or enter a question link or numeric id'. However, the beginning of this box is hidden from view, and scrolling to the left doesn't work, as the dialog is clipped:
Long pressing the part of the box, to bring up the context menu with the Paste option doesn't work. I have a workaroud: type a long text like "testtesttesttesttesttest" and eventually it will become visible, so that you can Select All and then Paste, but it's rather cumbersome. It takes so long that a GIF of the screencast is more than 3x the maximum size for embedding via imgur, so you'll have to settle for this YouTube link instead.