Affected versions

• Firefox 89.0
• Latest Nightly 90.0a1

Affected platforms

• Windows 10 64bit
• MacOS 11.3
• Ubuntu 18.04

Steps to reproduce

1. Start Firefox
2. Visit https://www.w3schools.com/html/tryit.asp?filename=tryhtml_elem_textarea
3. Right click inside textarea
4. Enable Check Spelling (if not already enabled)
5. Right click inside textarea again
6. Select This Frame and Reload Frame
7. Right click inside the textarea again

Expected result

• The same labels are displayed inside contextmenu

Actual result

• Check Spelling and Languages are missing from contextmenu also the left padding used by the checkmark icon is missing as well from both contextmenus.

Regression range

• This is not a regression, it also reproduces in the first Nightly where browser.proton.contextmenus.enabled pref was first available in about:config (in bug 1698132)

Additional notes

• If dismissing the faulty contextmenu and enabling it again, it will be displayed as expected.

Suggested severity

• Since this is fixed if context menu is reopened and not sure who many users will run into this I would say it should have an S3 severity since the issue is about missing labels.

Can you still reproduce if you wait 5 seconds after using "Reload Frame", before reopening the context menu on the multiline text field?

I suspect this is just a race condition to do with when spellcheck is initialized.

This is not a regression, it also reproduces in the first Nightly where browser.proton.contextmenus.enabled pref was first available in about:config (in bug 1698132)

What about non-proton? I expect this reproduces in non-proton, and it should be possible to check if it's a regression pre-proton, or if it's been broken in this way for a long time.

Yeah, this is also reproducible without proton enabled, and yes waiting a few seconds (3 or so) after reload does indeed make the spellcheck options appear but only if I first focus the frame.
If I focus the textarea with left click and then bring up the context will make the spellcheck appear but if I right click inside the textarea without focusing it before, will not display it. (with or without proton)

Digging a bit more with mozregression I found out that using Nightly from 2018-04-02 is not affected by this issue and 2018-04-03 is. Here is the pushlog between 2018-04-03 and 2018-04-02: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=445255800255bb13ed096b5b7da36aa835e41dd8&tochange=00bdc9451be6557ccce1492b9b966d4435615380

This was last changed by bug 1448200 (reproducing similar behavior as non-e10s). Initializing the spell checker without any prior interaction will most likely cause performance issues since the vast majority of inputs and textareas are never interacted with.

As such, I'm going to close this bug as 'wontfix'.