I agree that this is how most (non-technical?) people see a patch. But when you use Linux and compile programs you know that there are other patches as well. Earlier versions of OpenSSH had a chroot patch which didn't fix any bugs but added functionality. And in the Linux world there are other examples as well.
Wikipedia
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"A patch is a piece of software designed to update a computer program or its supporting data, to fix or improve it. This includes fixing security vulnerabilities and other bugs, with such patches usually called bugfixes or bug fixes, and improving the usability or performance."
So you could call mapping.xml a patch. It improves the story for some of us

. I don't remember but probably I have also used the word patch in earlier posts

.