Some nodeName of XML elements return uppercase.

Fixed Issue #13624999


Sep 7, 2017
This issue is public.
Reported by 1 person

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Conflict Contact

Daniel Clark (daniec)

Submitted by

Daniel clark

What is the issue?

This fixes a regression introduced in RS2 from performance work.  We should not be returning uppercase for nodeName, which broke an enterprise application.  The fix has flighted since Mid July and a DRT has been created as well.  This fix goes back to the W3C standard behaviour that is supported all modern browsers.

How was the issue/bug found?


Quantify the impact of the issue - why do we need to service this issue now?

Not a super common part of the Web (nodeName+XML) but people that are using this API are not expecting upper case values. 

Is the fix ready and what is it?

Fix is ready and just goes back to the former behaviour

​How was the fix Validated?

​The fix has been flighted and DRTs were created as well

Regression risk level of the fix

Very Low

Has the fix been flighted in a RS3 flight?

Yes it has been flighted with no regressions observed

​Do you have any data points that can be monitored to ensure that the fix works or if there are adverse effects from the fix?


​Does this fix need to be backported to TH2 or RS1 or prior releases (for CBB/LTSB customers)?

​No, only backport to RS2

QD signing off on this change


How to validate/test for regressions

(required for WSD pre-release validation)

Scenario to validate



Some nodeName of XML elements return uppercase in Microsoft Edge 40.15063.0.0.

I parse an XML that looks like this

<html xmlns="">

using DOMParser.

var parser = new DOMParser();
var dom = parser.parseFromString(str, "text/xml");

However, when I serialize XML using DOM API, I get

<html xmlns="">

dom.documentElement.firstChild.tagName returns "body".
But, dom.documentElement.firstChild.nodeName returns "BODY".

Why are some elements returned in uppercase?

You can test here.


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    Comments and activity

    • Microsoft Edge Team

      Changed Status to “In progress”

      Changed Assigned To to “travil”

      Changed Status from “In progress”

      Changed Assigned To to “”

      Changed Assigned To from “” to “Ying C.”

      Changed Status to “In progress”

      Changed Assigned To from “Ying C.” to “Kris K.”

      Changed Status from “In progress” to “Fixed”

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