bug#50061: 28.0.50; Hang caused by savehist-save when saving kill ring with large amount of data from nxml-mode buffer

[Eli Zaretskii]

> Date: Sun, 15 Aug 2021 10:36:35 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 50061@debbugs.gnu.org
> 
> nXML puts a lot of its private text properties on the text.  My guess
> is that producing a printed representation for that consumes
> inordinate amounts of memory.

Specifically, it's the 'rng-state' property on the "</p>" that ends a
paragraph.  It's a massive recursive data structure, and printing it
takes a lot of memory.  Maybe nXML could arrange for these properties
to be removed when copying to the kill-ring, but would it get in the
way if you want to paste into an XML buffer?