Subject: bug#46764: Extra ">" sails right past XML validator

From: Mattias Engdegård <[email-masked]>
Date: Fri, 26 Feb 2021 10:21:44 +0100

">" is not a special character at top level in XML; <M>></M> is well-formed.

I agree that it is an easy mistake to make and overlook. Perhaps an optional warning would be helpful?
Note that nxml-mode is carefully written for correctness and performance, which matter because XML is a lot more complex than people think and files can be large. Any tinkering with it has to be done with prudence.