1471552 - Some panels from DevTools disappear when the browser is resized

Status: NEW

(DevTools :: Inspector, defect, P3)

Description

[Oana Botisan, Desktop Release QA]

Attachment: disappearing panels by resizing.gif

[Affected versions]:
- Firefox 61.0
- Firefox 62.0b3
- Nightly 63.0a1

[Affected platforms]:
- Windows 10 x64
- Ubuntu 16.04 x64
- macOS 10.13

[Steps to reproduce]:
1. Open about:newtab
2. Open Devtools -> Inspector.
3. Enable the "Toggle 3-pane inspector"
3. Resize the browser.

[Expected result]:
- All the panels are visible or rearranged in order to be visible or scrollbars appear in order to see the content of each panel.

[Actual result]:
- Some of the panels disappear. 

[Regression range]:
- I don't think is a regression. 

[Additional notes]:
- Please look at the attachment to see the bug reproducing.
- This issue reproduces even if DevTools are opened in a separate widow.
- It also reproduces in Debugger, Style Editor, Network, Storage.

Comment 1

[Julian Descottes [:jdescottes]]

When resizing the window, you trigger the "vertical layout" which for the inspector in 3-pane means going from

----------------------------
|        |        |        |
| markup | rules  | sidebar|
|        |        |        |
|        |        |        |
----------------------------

to
-------------------
|     markup      |
|                 |
-------------------
|  rules |sidebar |
|        |        |
-------------------

With your current toolbox height the "markup" part starts very small so maybe there is something to improve there. 
Is this what this bug is about? 
Otherwise please give more details about which panel disappears?

Comment 2

[Oana Botisan, Desktop Release QA]

Yes. That is what the bug is about. I am sorry I didn't make the problem more clear. 

The problem is that the rules and sidebar panes slide beneath the markup one, but there is no scrollbar and the focus is only on the bottom panes. The markup pane disappears completely and it can be seen only if the Devtools window is resized vertically. 

I hope this clears up the issue a bit.