Found in

• 106.0b4

Affected versions

• 107.0a1
• 106.0b4

Tested platforms

• Affected platforms: Win 10, Win 7
• Unaffected platforms: Win 11

Preconditions

• Have Firefox 32-bit installed

Steps to reproduce

1. Launch Firefox.
2. Open a New Private Window from the App Menu.
3. Right click on the PBM icon from the taskbar and pin it.
4. Right click again on the PBM icon and unpin it.

Expected result

• The PBM icon is correctly unpinned.

Actual result

• The PBM icon turns into a blank one.

Regression range

• We will find the regression asap, if there is one.

Additional notes

• This seems to be an intermittent issue as I cannot reproduce it regularly. I will post a screencast as soon as I'm hitting this bug once again.
• I was not able to reproduce this using Firefox 64-bit builds.

Thanks for the report. A reliable STR would be wonderful here, fingers crossed!

It's entirely possible this is a Windows bug that we may not be able to fix, but let's see.

The issue is reproducing at a faster rate if the Private Window is pinned from the installation folder.
Also at some point only the option for "Pin to taskbar" is available. I think that this could be the cause of this bug.

It seems that with the steps seen in the above screencast, we are able to reproduce the blank icon with Firefox normal icon as well, and even with the Microsoft Edge one. What do you think Ben, is there something to fix here, or it's a Win bug after all?

(In reply to Oana Botisan, Desktop Release QA from comment #2)

Created attachment 9296446 [details]
blank icon.gif

The issue is reproducing at a faster rate if the Private Window is pinned from the installation folder.
Also at some point only the option for "Pin to taskbar" is available. I think that this could be the cause of this bug.

Oh -- now I wonder if this is a dupe of https://bugzilla.mozilla.org/show_bug.cgi?id=1792546 ? It looks like it to me based on your screencast -- what do you think?

(In reply to Ciprian Georgiu [:ciprian_georgiu], Release Desktop QA from comment #3)

It seems that with the steps seen in the above screencast, we are able to reproduce the blank icon with Firefox normal icon as well, and even with the Microsoft Edge one. What do you think Ben, is there something to fix here, or it's a Win bug after all?

It's definitely something Windows is causing. Whether or not we can do anything about it is another question.

(In reply to bhearsum@mozilla.com (:bhearsum) from comment #4)

(In reply to Oana Botisan, Desktop Release QA from comment #2)

Created attachment 9296446 [details]
blank icon.gif

The issue is reproducing at a faster rate if the Private Window is pinned from the installation folder.
Also at some point only the option for "Pin to taskbar" is available. I think that this could be the cause of this bug.

Oh -- now I wonder if this is a dupe of https://bugzilla.mozilla.org/show_bug.cgi?id=1792546 ? It looks like it to me based on your screencast -- what do you think?

It doesn't seem so, on the above bug we're referring to the PBM icon string, that is named "private_browsing”. We're pinning/unpinning the PBM icon from the installation folder, because we found out that this way the issue has a higher repro rate, as Oana also commented.

(In reply to Ciprian Georgiu [:ciprian_georgiu], Release Desktop QA from comment #5)

(In reply to bhearsum@mozilla.com (:bhearsum) from comment #4)

(In reply to Oana Botisan, Desktop Release QA from comment #2)

Created attachment 9296446 [details]
blank icon.gif

The issue is reproducing at a faster rate if the Private Window is pinned from the installation folder.
Also at some point only the option for "Pin to taskbar" is available. I think that this could be the cause of this bug.

Oh -- now I wonder if this is a dupe of https://bugzilla.mozilla.org/show_bug.cgi?id=1792546 ? It looks like it to me based on your screencast -- what do you think?

It doesn't seem so, on the above bug we're referring to the PBM icon string, that is named "private_browsing”. We're pinning/unpinning the PBM icon from the installation folder, because we found out that this way the issue has a higher repro rate, as Oana also commented.

Thanks. I also confirmed that the patch from bug 1792546 doesn't fix this issue (oh well...). In any case, given that:
a) This can only happen when pinning in an unlikely way
b) The same thing that can happen when pinning Edge in this way
c) The issue is cosmetic

...I'm downgrading this to S4. Happy to accept a patch for this, but I don't think there's any way we'll prioritize fixing it ourselves, if we even can.

Given the nature of this bug, I think will be quite hard to find an accurate regression range.