1466183 - Attaching a shadow root to the DOM should cause pretty print to drop

Status: NEW

(Core :: XML, enhancement, P3)

Description

[Tim Guan-tin Chien [:timdream] (please needinfo)]

See bug 1437956 comment 13. For pretty printed XML document where it is possible to attach shadow DOM to its node, i.e. XBL & XSLT documents with allowed HTML elements, we don't leave pretty print when a shadow DOM is attached just as we do when the DOM is modified.

You can test this out with, for example,

https://hg.mozilla.org/mozilla-central/raw-file/9900cebb1f90/dom/xml/resources/XMLPrettyPrint.xml

and do

document.documentElement.firstElementChild.firstElementChild.firstElementChild.attachShadow({ mode: 'open'});

in the DevTools console.