Affected versions

• 83.0a1(2020-10-12)
• 82.0a(20201012131351)

Affected platforms

• macOS 10.14
• Ubuntu 18.04
• Windows 10x64
• Windows 7x64

Steps to reproduce

1. Launch FF.
2. Go to the burger menu
3. Go to Customize.
4. Put the Print button anywhere on the Toolbar.

Expected result

• Button is active and can be interacted with as soon as it has been set on the toolbar.

Actual result

• Button is greyed out and cannot be interacted with.

Suggested Severity

• Seeing as how this issue occurs on all devices used in our testing, but not blocking our access to the feature(there are multiple other ways to trigger modal) , I would S3 this issue

Regression range

• https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=70d0999325356b15d9b8b821a03cbd55ebf09b78&tochange=19eeff321de5d47400d4eea3b77b605884eaa598
  Potential regressor: 1663173

Additional notes

• Print button can be interacted with as soon as the browser is restarted.
• Print button becomes unresponsive and greyed out as soon as the user changes its position.
• All other means of accessing the new modal are not compromised.
• This issue occurs for both old and new UI.
• Screen-cast of the issue: https://drive.google.com/file/d/1fkBnTN5SDjHiGpoFLD6Mi_s6NEWV2yA4/view?usp=sharing

Does this only affect print? What about other buttons that aren't in the toolbar by default (e.g. "save page as...", "file open", etc.)?

Yes, I was only able to reproduce this with the Print button.

I just tried with all the other buttons and all are working accordingly and do not display this behavior.

https://drive.google.com/file/d/1Ht4EybZ84YGDrWjrutvAabPT96SfPdy9/view?usp=sharing

As you can see in this above attachment, only the Print button is greyed out.

When we move items in customize mode, we unwrap them, then move them, then wrap
them again. The unwrapping sets the command attribute back on the button, and
that also sets the disabled attribute on the button. The wrapping removes the
command attribute but leaves the disabled attribute.
When the disabled attribute is removed from the command, this does not
propagate to the button because the command attribute has not been put back.

To fix this, the patch avoids adding and immediately removing the command
attribute when moving items while in customize mode.

Considering this only affects print and a new window or restart works, this doesn't seem super high severity.

wontfix for 82 based on comment 4.

https://hg.mozilla.org/mozilla-central/rev/bd5fbe4e35a3

Hello,

I have verified this issue on 84.0a1(20201026092834) and 83.0b4(20201025174155) with Windows 10x64 , macOS 10.15.7 and Ubuntu 18.04x64.

This issue is only partially fixed.

Moving the print icon to the toolbar as in the STR above, will now lack functionality until the browser is restarted.
Would you prefer to close this one and open a new issue for the new behavior?

(In reply to Vlad Lucaci, QA (:vlucaci) from comment #8)

Hello,

I have verified this issue on 84.0a1(20201026092834) and 83.0b4(20201025174155) with Windows 10x64 , macOS 10.15.7 and Ubuntu 18.04x64.

This issue is only partially fixed.

Moving the print icon to the toolbar as in the STR above, will now lack functionality until the browser is restarted.
Would you prefer to close this one and open a new issue for the new behavior?

Ugh. Thanks for flagging this up. I filed bug 1673388 so we can track release status flags.

Closing this issue as per the comment above.