1351666 - Compact themes not kept in the list of my themes from customize when switching through light themes

Status: RESOLVED DUPLICATE of bug 1402981

(Firefox :: Theme, defect, P2)

Description

[Bogdan Maris, Desktop Test Engineering]

[Affected versions]:
- Firefox 53 beta 7
- latest Developer Edition 54.0a2
- latest Nightly 55.0a1

[Affected platforms]:
- macOS 10.12.2
- Ubuntu 16.04 32bit
- Windows 10 64bit

[Steps to reproduce]:
1. Open Firefox, install 5 or more light themes
https://addons.mozilla.org/en-US/firefox/themes/
2. Visit about:addons#appearance and enable a compact theme.
3. Enter Customize, select Themes and pick one
4. Click Themes again

[Expected result]:
- Compact theme (being the second last theme used) is still displayed in My Themes list under Default and the actual selected theme.

[Actual result]:
- Compact theme is missing from My Themes list.

[Regression range]:
- This is not a recent regression, it also reproduces on old Nightly from 2017-01-15 when compact themes was introduced by default in Nightly.

[Additional information]:
- Not sure if this is intended or not, but I think those themes should behave like other light themes. Once I have many themes installed, I can only enable the compact theme from about:addons#appearance and other light themes can be enabled from customize.

Comment 1

[Jeff Griffiths (:canuckistani) (:⚡︎)]

How many is "many"? is it exactly 5?

Comment 2

[Bogdan Maris, Desktop Test Engineering]

(In reply to Jeff Griffiths (:canuckistani) (:⚡︎) from comment #1)
> How many is "many"? is it exactly 5?

Just to be extra clear with the [Additional information]:
- If one installs exactly 4 lightweight themes and open My Themes from customize, the 5th will be one of the compact themes (Default theme not included) and the second compact theme will not be displayed.
- Installing a 5th lightweight theme will make compact themes disappear from My Themes from customize making them accessible only from about:addons#appearance. 
- When enabling any of the compact themes (from about:addons) it will be displayed in My Themes until any of the previously 5 lightweight themes is enabled. 
- Once this happens, the previously enabled compact theme will disappear from My Themes dropping down to 6th and 7th installed themes, which are not displayed. 

Basically whenever a lightweight theme is enabled, the compact themes are always the last two from the list, even though one of them was previously used. I hope this answers your question. Let me know if can provide any additional information.

Comment 3

[:Gijs (he/him)]

This was fixed in bug 1402981.