Packager.pm uses fileparse to attempt to get the extension of files so that it can see if any are manifest files and so do special things with them. It passes the regex '\..*?$'. I assume that whoever wrote it made it non-greedy might have thought that meant it would only match everything from the last . onwards but it still matches anything from the first . so it thinks a file like "pdf.js.manifest" has the extension ".js.manifest". A better regex to use would be '\.[^\.]*$'. No idea how scary changing that is though.
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