Weird EPUB bug: empty image files in the IRS i1040gi.epub file

This EPUB bug brought to you by the IRS and their i1040gi.epub file Normally government EPUB files are pretty good about making usable EPUB files. But this year only, the IRS's "i1040gi.epub" file (the file with USA government tax information for filing out the very common 1040 tax form) has a subtly malformed epub file. The list of images (EPUB/img) has 28 GIF files which are all fine, and one…