Previewing an attachment on a card cuts off larger pages

Issue Summary

When previewing a PDF attachment on a card the previewer seems to default to A4 page size and cuts off larger pages.

Steps to Reproduce

1. Attach a PDF document to a card with pages larger than a4 (e.g. a3)
2. Preview the PDF

Expected Results

The preview should open and show the entire page

Actual Results

The preview opens with some of the page cut off and you need to zoom out to show the entire page.

Workaround

You can zoom out to view the entire page, however, if you're also printing the PDF directly from the preview with Right-click then Print, not all browsers remember the zoom out so try to print the PDF with the page cut off; this means the customer has the extra steps of downloading the PDF, then opening again, then printing.