1914665 - Developer Toolbox: "Edit as XML" on a XUL Element deletes the Element

Status: NEW

(DevTools :: General, defect, P3)

Description

[Mark Barnes [:WoofGrrrr]]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:129.0) Gecko/20100101 Firefox/129.0

Steps to reproduce:

128.1.1esr on WIn 11 Pro x-64

1. Open Developer Toolbox Inspector
2. Find a XUL Element, e.g <treecol>
3. Right-click on it
4. Select "Edit as XML"
5. Add an attribute to the Element
6. right-click on any other Element to close the edit

In my case the XUL Element was this:

<treecol xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         id="unifinder-search-results-tree-col-title"
         persist="hidden ordinal width"
         style="flex: 1 1 auto; order: 1; width: 552px;"
         closemenu="none"
         itemproperty="title"
         data-l10n-id="calendar-event-listing-column-title"
         label="Title"
         tooltiptext="Sort by title"
         ordinal="1"
         width="552">
  <label class="treecol-text" flex="1" crop="end" value="Title"/>
  <image class="treecol-sortdirection"/>
</treecol>

I added Attribute class="abc"

Actual results:

The XUL Element gets completely deleted.

I see these message in the Console:

13:27:32.159 Flattening unsafe node (descendants are preserved). Element: treecol. walker.js:1604:7
13:27:32.159 Flattening unsafe node (descendants are preserved). Element: label. walker.js:1604:7
13:27:32.159 Flattening unsafe node (descendants are preserved). Element: image. walker.js:1604:7

Expected results:

The XUL Elements should not get deleted

Comment 1

[Francesco]

The DevTools come from Firefox, this bug should be moved to Product: DevTools.