Affected versions

• 80.0a1 (20200726214746)
• 79.0 (20200720193547)
• 78.0.2 (20200708170202)
• 78.1.0esr (20200722151235)

Affected platforms

• Windows 10x64
• macOs 10.12
• Ubuntu 18.04

Steps to reproduce

1. Open Firefox web console.
2. Type a random letter (e.g a) and press Enter.

Expected result

• Context menu is no longer shown.

Actual result

• Blank context menu is displayed.

Regression range

• Last good revision: 0b092833a6efffb9709c16c12854b3c898f71888
• First bad revision: a2ebc0c68234d99bb4e598b9f1e3f4902df9ad54
• Pushlog:
  https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=0b092833a6efffb9709c16c12854b3c898f71888&tochange=a2ebc0c68234d99bb4e598b9f1e3f4902df9ad54
• Possible regressor: bug 1609942.

Notes

• Attached a screen recording.
• Note that the issue may require several times to reproduce due to timing.

Severity S3

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

For more information, please visit auto_nag documentation.

Sometimes, it might happen that the user triggered the popup
opening (by typing a letter) and hit Enter before the popup
was already shown, which would result in a blank popup being opened.
This patch addresses that by storing the popup opening promise
and if it exists in the code that handle the Enter key, wait until
the promise resolves and hide the popup.

It would be tricky to write a consistent test as this race is depending
on the server response time and the time it take for the popup to be
shown; but manual tests seemed to indicate this fixes the issue.

https://hg.mozilla.org/mozilla-central/rev/2c15c7f0d3c6

Reproduced the issue with Firefox 81.0a1 (20200727203201) on Windows 10x64.
The issue is verified fixed with Firefox 81.0b8 (20200908191057) on Windows 10x64, macOS 10.12 and Ubuntu 18.04.