Closed Bug 1307101 Opened 5 years ago Closed 4 years ago

WebExtensions: browserAction popup text briefly appears blurred after opening popup


(WebExtensions :: Frontend, defect)

51 Branch
Windows 10
Not set


(Not tracked)



(Reporter: dw-dev, Unassigned)


User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0
Build ID: 20160823121617

Steps to reproduce:

I have created a new WebExtensions add-on (Zoom Page WE) based on my well-established XUL/XPCOM Zoom Page add-on.

When I click on the Zoom Page WE browserAction toolbar button, the popup opens, but all of the text appears slightly bolder and slightly blurred for brief period (probably half a second).

This problem was introduced in Firefox 51.0 and does not happen with earlier versions.

This problem does not happen if the browserAction is replaced by a pageAction using the same popup.html file.

I suggest you install Zoom Page WE 2.1 to reproduce and see the problem.

Actual results:

The text in the browserAction popup appears slightly bolder and slightly blurred for a brief period (probably half a second) after the popup is opened.

Expected results:

The text in the browserAction popup should appear correctly rendered immediately the popup is opened.
I suspect this problem is related to Bug 1215025, and more specifically to the extra 1px width mentioned in Bug 1280146.
OS: Unspecified → Windows 10
Version: 48 Branch → 51 Branch
Component: Untriaged → WebExtensions: Untriaged
Product: Firefox → Toolkit
Vasilica, can you or someone on your team please test this, and attach a screencast if you can confirm it? I tested on Linux and could not reproduce on Linux or OS-X, and I don't currently have access to Windows 10 to test on.

dw-dev, a screencast from you would also be helpful, if you can provide one.

No longer blocks: webext-popups
Flags: needinfo?(vasilica.mihasca)
Component: WebExtensions: Untriaged → WebExtensions: Frontend
I was able to reproduce this issue on Firefox 51.0a2 (2016-10-10) under Windows 10 64-bit ( but it is not reproducible in Firefox 52.0a1 (2016-10-09).

Performed a regression range and I suspect that this is a dupe of Bug 1303570 (

dw-dev , can you please confirm that this issue is not reproducible in latest Nightly (
Flags: needinfo?(vasilica.mihasca) → needinfo?(dw-dev)
agreed looks like duplicate in triage
Closed: 4 years ago
Resolution: --- → DUPLICATE
Duplicate of bug: 1303570
No longer blocks: webext-popups
Flags: needinfo?(dw-dev)
I can confirm that this issue does not happen with Nightly 52.0a1 (2016-10-11).
Product: Toolkit → WebExtensions
You need to log in before you can comment on or make changes to this bug.