1736183 - After triggering "Pick an element" (Ctrl+Shift+C) twice, element rectangle doesn't appear until you hover a different element

Status: RESOLVED FIXED

(DevTools :: Inspector, defect, P3)

Description

[nyanpasu64]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:93.0) Gecko/20100101 Firefox/93.0

Steps to reproduce:

• Visit https://www.baldurbjarnason.com/2021/single-page-app-morality-play/.
• Press Ctrl+Shift+C, then hover the document and click an element.
  • Alternatively open the inspector with F12, then click the "Pick an element from the page" button and click an element partially covered by the dev tools.
• Before or after the blue rectangle disappears (1 second after click), press Ctrl+Shift+C.
  • Alternatively click the "Pick an element from the page" button and move your mouse to the same element selected earlier.

The bug is unaffected if (between the 2 "pick element" operations) you move the mouse onto a different element and back to the first element, or hover or click on the DOM tree view.

Actual results:

On the first Ctrl+Shift+C, the blue rectangle doesn't appear until you move your mouse.

On the second Ctrl+Shift+C, the blue rectangle (the bounding box of the currently pointed rectangle) won't appear until you move the mouse out of the current element into a different one.

Expected results:

I think the blue rectangle should appear immediately below the mouse cursor in both cases (instead of waiting for the mouse to move, or onto a different element altogether).

Comment 1

[nyanpasu64]

Actually I was able to reproduce the bug on Bugzilla too (though the URL I initially mentioned works).

Comment 2

[Daniel Bodea [:danibodea]]

I can confirm this issue on all platforms and apparently, it is a regression because it occurs on Nightly v95.0a1, Beta v94.0b8, Release v93.0 or ESR v91.1.0esr, but it does not occur on ESR v91.2.0esr, ESR v78.14.0esr and ESR v78.15.0esr.

Unfortunately, an exact push log could not be determined because mozregression gives out the error of not being able to bisect because of not enough builds data.
Best result:
2021-10-20T15:35:35.410000: INFO : Narrowed nightly regression window from [2020-07-06, 2020-07-08] (2 days) to [2020-07-07, 2020-07-08] (1 days) (~0 steps left)

The regression investigation was done on Windows10 and MacOS11 with the same result.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

:danibodea, since this bug is a regression, could you fill (if possible) the regressed_by field?
For more information, please visit auto_nag documentation.

Comment 4

[Daniel Bodea [:danibodea]]

(In reply to Release mgmt bot [:sylvestre / :calixte / :marco for bugbug] from comment #3)

:danibodea, since this bug is a regression, could you fill (if possible) the regressed_by field?
For more information, please visit auto_nag documentation.

No, I can not. more info in comment 2.

Comment 5

[Jan Honza Odvarko [:Honza] (always need-info? me)]

I can't reproduce the problem in 96 (Nightly)
Nicolas, could this be related to some of the bugs you fixed recently?

Honza

Comment 6

[Nicolas Chevobbe [:nchevobbe]]

I can still reproduce the issue:

1. Open a tab with data:text/html,<meta charset=utf8><button>First button</button><button>Second one</button>
2. Ctrl+Shift+C (or Cmd+Shift+C on OSX) and hover First button
3. Click on the button, the highlighter is hidden
4. Without moving the mouse Ctrl+Shift+C (or Cmd+Shift+C on OSX) again

Result: the highlighter is not displayed, and it won't until I hover another element than First button (so either Second one, or the body)

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:jdescottes, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 8

[Julian Descottes [:jdescottes]]

Attachment: Bug 1736183 - [devtools] Reset hovered node reference when cancelling node picker

Quick patch, but needs test coverage

Comment 9

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Nicolas, do you want to add this bug (patch available) to your TODO list related to the node picker?

Honza

Comment 10

[Nicolas Chevobbe [:nchevobbe]]

Sure, I'll add a test on top of Julian's patch from Comment 8
I wonder if we should also try to trigger a "hover" if you use the shortcut to enable the picker while the mouse is on the content page

Comment 11

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Bug 1736183 - [devtools] Add test for reset of node picker hovered node reference. r=ochameau.

Depends on D131375

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/fb195fa55987
[devtools] Reset hovered node reference when cancelling node picker r=nchevobbe
https://hg.mozilla.org/integration/autoland/rev/cff5f42a63f8
[devtools] Add test for reset of node picker hovered node reference. r=ochameau.

Comment 13

[Cristina Cozmuta (:CrissCozmuta)]

https://hg.mozilla.org/mozilla-central/rev/fb195fa55987
https://hg.mozilla.org/mozilla-central/rev/cff5f42a63f8

Comment 14

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:jdescottes, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment 15

[Julian Descottes [:jdescottes]]

This can ride the trains, it's not breaking any workflow severely.

Comment 16

[Virgil Sangerean]

Managed to reproduce on 2021-10-16-09-48-19. FF nightly.

On Windows 10, Ubuntu 20 and Mac, the issue is randomly reproducible while using version 97.0b9.

Please see attached video

Comment 17

[Virgil Sangerean]

Attachment: Issue1736183.gif

Comment 18

[Nicolas Chevobbe [:nchevobbe]]

(In reply to Virgil Sangerean from comment #16)

Managed to reproduce on 2021-10-16-09-48-19. FF nightly.

On Windows 10, Ubuntu 20 and Mac, the issue is randomly reproducible while using version 97.0b9.

Please see attached video

Virgil, it's hard to see what steps you are taking just looking at the videos, could you explain a bit more?

Comment 19

[Nicolas Chevobbe [:nchevobbe]]

I can see that we're still not showing the highlighter when you enable it from keyboard shortcut until the mouse move, but you don't have to move to a different element to see the highlighter (see Comment 10).
We should have a dedicated bug for that.

Comment 20

[Virgil Sangerean]

(In reply to Nicolas Chevobbe [:nchevobbe] from comment #18)

(In reply to Virgil Sangerean from comment #16)

Managed to reproduce on 2021-10-16-09-48-19. FF nightly.

On Windows 10, Ubuntu 20 and Mac, the issue is randomly reproducible while using version 97.0b9.

Please see attached video

Virgil, it's hard to see what steps you are taking just looking at the videos, could you explain a bit more?

The same steps were performed as presented in the description and in comment 6.

Comment 21

[Nicolas Chevobbe [:nchevobbe]]

okay, so just to be extra clear, with the following STR:

1. Open a tab with data:text/html,<meta charset=utf8><button>First button</button><button>Second one</button>
2. Ctrl+Shift+C (or Cmd+Shift+C on OSX) and hover First button
3. Click on the button, the highlighter is hidden
4. Without moving the mouse Ctrl+Shift+C (or Cmd+Shift+C on OSX) again
5. Move the mouse a few pixel inside First button

you don't get the highlighter displayed on First button ?

Comment 22

[Virgil Sangerean]

(In reply to Nicolas Chevobbe [:nchevobbe] from comment #21)

okay, so just to be extra clear, with the following STR:

1. Open a tab with data:text/html,<meta charset=utf8><button>First button</button><button>Second one</button>
2. Ctrl+Shift+C (or Cmd+Shift+C on OSX) and hover First button
3. Click on the button, the highlighter is hidden
4. Without moving the mouse Ctrl+Shift+C (or Cmd+Shift+C on OSX) again
5. Move the mouse a few pixel inside First button

you don't get the highlighter displayed on First button ?

Sorry for the late reply.

Yes, I can confirm that while doing the steps mentioned above, in many occasions the highlighter is NOT displayed.
I can confirm that this is the scenario also for FF 98.0b4 on Windows 10 and Ubuntu 20.