1303699 - The devices list is wrongly displayed if a small device is selected after 4K Ultra HD Television device

Status: RESOLVED WORKSFORME

(DevTools :: Responsive Design Mode, defect, P3)

Description

[Mihai Boldan, Desktop QA [:mboldan]]

[Affected versions]:
- 51.0a1 (2016-09-18) 

[Affected platforms]:
- Windows 10x64, Mac OS X 10.11.1, Ubuntu 16.04x64

[Steps to reproduce]:
1. Launch Firefox.
2. From about:config, enable the devtools.responsive.html.enabled pref.
3. Enable RDM.
4. Choose '4K Ultra HD Television' device.
5. Scroll the page to the right, only until the device button is displayed.
6. Choose a small device from the list (Eg. Samsung Galaxy S5).
7. Open the devices list.

[Expected result]:
- The list is correctly displayed under the selected device button.

[Actual result]:
- The list is not centered. See https://i.imgur.com/gYubpyo.png.

[Regression range]:
- This issue is not a regression.
- Here is the pushlog https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=4037eb98974db1b1e0b5012c8a7f3a36428eaa11&tochange=3587b25bae302c1eed72968dbd7cef883e715948.

[Additional notes]:
- The issue is not reproducible if at step 5, the page is scrolled to the right until the device button hits the middle of the window.
- Note that this issue is reproducible only if previously the '4K Ultra HD Television' device is selected.

Comment 1

[Mihai Boldan, Desktop QA [:mboldan]]

This issue is no longer reproducible on Firefox 134.0b10. Tests were performed under Windows 11x64.