1062974 - Size of <iframe> inside <panel type="arrow"> gets messed up the second time the panel is opened

Status: NEW

(Toolkit :: UI Widgets, defect)

Description

[Manvel Saroyan]

Attachment: Test add-on that case panel content disappearance.

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.94 Safari/537.36

Steps to reproduce:

1. Install provided testing add-on (popup-test.xpi).
2. Click on toolbarbutton of installed addon.
3. Click on "Change Icon" button in opened panel.


Actual results:

Toolbarbutton image changed, but content of Panel type="arrow" disappears.


Expected results:

Changing image of toolbarbutton should not cause the content of panel to disappear.

Comment 1

[Manvel Saroyan]

Attachment: (additional) Test add-on that cause panel content disappearance without binding.

After investigating mozilla's panel type=arrow binding and look through it's xbl, also noticed that the issue appear when the panel's children in our case iframe is placed inside XUL box element. 
This is additional reproduction addon, where I've removed -moz-binding from panel (set to none) element and placed iframe in the vbox element and the issue still persist, I hope this information can also be helpful.

Comment 2

[Wladimir Palant]

Attachment: Test add-on showing the issue

I was able to simplify the test add-on, the issue isn't really related to styles.

Comment 3

[Wladimir Palant]

New steps to reproduce:

1. Install the test add-on from attachment, a window will open.
2. Click the "Click me" button, note the red border around the entire panel content (<iframe>).
3. Click the "Click me" button again.

Expected result:

There will a be red border around the entire panel content again (<iframe> size doesn't change).

Actual result:

The red border is on the left side of the panel content, the width of the <iframe> is zero for some reason (Firefox 35.0a1 nighty 2014-09-04 on OS X).

The source code of this button is really just the following:

    <toolbarbutton label="Click me" type="panel">
      <panel type="arrow">
        <iframe src="about:blank" width="100" height="100" style="border: 1px solid red;"/>
      </panel>
     </toolbarbutton> 

Note that <iframe> size is set explicitly, there is no reason it should change. If I use <vbox> instead then its size doesn't change. Same thing if I remove type="arrow". My suspicion is that this has something to do with the way <panel type="arrow"> is being animated.

Comment 4

[Wladimir Palant]

It seems that in the variation described above this issue is only reproducible on OS X.