1045689 - Dragging tab off that is in responsive design mode creates an empty tab in a new window and leaves an empty, unusable space where the original tab was

Status: RESOLVED WORKSFORME

(Firefox :: Tabbed Browser, defect)

Description

[Brandon Frohs]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:31.0) Gecko/20100101 Firefox/31.0 (Beta/Release)
Build ID: 20140715214327

Steps to reproduce:

1. Open http://example.org/ in a tab (in a window with other tabs open)
2. Open Responsive Design Mode
3. Click the example.org tab and drag it off the tab bar


Actual results:

New window was created with empty "New Tab" tab. example.org tab is still present in original window (no longer in Responsive Design Mode). Tabs (example.org and other tabs) an no longer be pulled off. Rearranging tabs ends with unexpected results (tabs are sometimes positioned on top of eachother, or don't snap into place).


Expected results:

example.org tab should be in its own window, and the other tabs should remain in the original window.

Comment 1

[Brandon Frohs]

On Linux, empty space is left where the example.com tab was. On Windows, the example.com tab is left in place (in the original window). In both cases, a new window is opened with an empty "New Tab" tab and tab arrangement becomes buggy.

Likely related to https://bugzilla.mozilla.org/show_bug.cgi?id=802819 (may be a duplicate).

Comment 2

[:Gijs (he/him)]

This works for me. Can you try in a new profile? ( https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles ) I wonder if an add-on is interfering...

Comment 3

[Brandon Frohs]

I've tried it in a new profile and experience the same issue. I also just tested on a separate Windows 7 machine and it happened there as well (non-tech user's machine, so none of the add-ons I have).

Comment 4

[:Gijs (he/him)]

I can reproduce on Linux with 31 as well as trunk. Not sure why I can't reproduce on OS X. :-\

There's an error in the browser console that says:

NS_ERROR_NOT_IMPLEMENTED:  browser.xml:1084

which points to:

          this.QueryInterface(Components.interfaces.nsIFrameLoaderOwner)
              .swapFrameLoaders(aOtherBrowser);

ie:

http://mxr.mozilla.org/mozilla-central/source/toolkit/content/widgets/browser.xml#1084

Not entirely sure if this is a responsive mode or a tab browser bug, but moving to the latter for now. This leaves the browser in a pretty bad state (the first window's UI is confused about how many tabs it has and/or where this docshell has gone), so I'm putting it in the backlog.

Comment 5

[:Gijs (he/him)]

Paul, I think you're probably still one of the people most familiar with responsive mode - any idea what would cause this?

Comment 9

[Tim Nguyen :ntim]

Err, wrong bug.

Comment 10

[Paul Rouget [:paul]]

We changed the way the responsive mode works recently, and I think it fixed this bug.

Feel free to re-open if you can still reproduce.