Re: SC 4.1.1 source fails but DOM passes - must a page fail?

Since the intent of 4.1.x is compatibility with assistive technology (AT),
and since AT uses the resulting DOM and rarely if ever see the actual 
original source code
I would recommend the HTML in the DOM is what needs to be "valid", 
because then you/we know the user agent + AT did their job correctly as 
intended by the author / web developer. 

see https://www.w3.org/WAI/WCAG21/Understanding/parsing.html - note it use 
term "content", not 'original source code:

...The intent of this Success Criterion is to ensure that user agents, 
including assistive technologies, can accurately interpret and parse 
content. 

__________
Regards,
Phill Jenkins
Check out the new system for requesting an IBM product Accessibility 
Conformance Report VPAT® at  able.ibm.com/request
pjenkins@us.ibm.com
Accessibility Executive
IBM Accessibility
linkedin.com/in/philljenkins/
www.ibm.com/able
twitter.com/IBMAccess




From:   "Bristow, Alan" <Alan.Bristow@elections.ca>
To:     "'w3c-wai-ig@w3.org'" <w3c-wai-ig@w3.org>
Date:   01/10/2019 02:41 PM
Subject:        SC 4.1.1 source fails but DOM passes - must a page fail?



All,
 
Tasked with declaring a page as passing or failing SC 4.1.1
https://www.w3.org/TR/WCAG20/#ensure-compat-parses
I am looking for an authoritative source to back up one or other of these 
two positions:
 
1. HTML source MUST validate, regardless of whether the DOM is valid once 
JavaScript has loaded
2. HTML source may be INVALID as long as the DOM is valid after JavaScript 
has loaded.
 
This is something that must have come up before but I am sorry to say I 
cannot find the answer.
 
I suspect, since:
a). browsers change the DOM
https://css-tricks.com/dom/#article-header-id-0
and,
b). some browsers are less capable than others and so some may fail to 
?mend? some invalid HTML
that I probably have to follow position 1. since it is unequivocal.
 
Thanks for any wisdom you can share.
 
Cheers,
 
Alan
 
Alan Bristow
Web Programmer
Policy and Public Affairs
Elections Canada
Desk 9-A-053
30 Victoria Street, Gatineau, QC K1A 0M6
alan.bristow@elections.ca
Tel.: 819-939-2232