Persist stops working if accessed prefwindow before onload

[Vano]

Hello.

I stumbled upon an issue - some (not all) persist attributes stop restoring it's persist value if I used document.getElementById("prefwindowID") before onload event was fired.
Example:

Code: Select all

<?xml version="1.0"?>

<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>

<prefwindow id="testWindow"
            title="testing persist when accessing nodes before onload event"
            xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
>
  <prefpane>
    <checkbox id="testCheckbox"
              label="testing persist on checkbox"
              onchange="this.setAttribute('checked', this.checked)"
              persist="checked"/>
    <tabbox id="testTabbox"
            selectedIndex="1"
            persist="selectedIndex">
      <tabs>
        <tab label="tab #1" linkedpanel="panel1"/>
        <tab label="tab #2" linkedpanel="panel2"/>
        <tab label="tab #3" linkedpanel="panel3"/>
      </tabs>
      <tabpanels>
        <tabpanel id="panel1"/>
        <tabpanel id="panel2"/>
        <tabpanel id="panel3"/>
      </tabpanels>
    </tabbox>
  </prefpane>
  <script type="application/javascript"><![CDATA[

/* persist selectedIndex on tabbox will stop working if uncomment next line */

//document.getElementById("testWindow");

  ]]></script>
</prefwindow>

Change to tab #1 or #3 and reopen the window. It should remember previously opened tab.

Now, uncomment document.getElementById("testWindow");
And reopen the window, it will automatically switch to tab #2 regardless which tab was previously opened. Checkbox state however doesn't get affected.


This seems to affect only prefwindow (together with <prefpane>), window and dialog are not affected.
Same issue reproducible if trying access testTabbox instead of testWindow, however accessing testCheckbox works just fine.

I'm looking for a way collect default values of persist'ed attributes, so I could reset them to default when needed.
The only way I could find so far is to read value from these attributes before onload event fired, unfortunately this issue makes it unacceptable.

Do you think this is a bug?