1728119 - Firefox tabCaptureVisibleTab API doesn't record the canvas content on Windows

Status: RESOLVED DUPLICATE of bug 1661869

(WebExtensions :: General, defect)

Description

[Christian Mariño]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Safari/537.36

Steps to reproduce:

1. Install addon on Windows that is using tabCaptureVisibleTab method from tabs API
2. go to website that has canvas element (e.g https://canvas.apps.chrome)
3. take a screenshot using tabs.tabCaptureVisibleTab method

Note: the same method in Mac is work fine.

Actual results:

You can see the content of the canvas appears in black in the image returned by tabs.captureVisibleTab

Expected results:

The content of the canvas should appear in the image returned by tabs.captureVisibleTab

Comment 1

[Christian Mariño]

Attachment: Firefox_Screenshot_2021-08-30T14-29-40.963Z.png

The image returned by tabs.captureVisibleTab on Windows

Comment 2

[Alex Cornestean]

Hello,

I reproduced the issue on the latest Release (91.0.2/20210823123856), Beta (92.0/20210830174627) and Nightly (93.0a1/20210831213957) under Windows 10 x64, using Firefox’s in-built screenshot feature (Firefox Screenshots).

I’ve also tested the same versions on Ubuntu 16.04 LTS, but the issue does not occur on this platform.

For further details, please see the attached screenshots depicting the actual canvas content and the capture using Firefox Screenshots.

Comment 3

[Alex Cornestean]

Attachment: actual canvas content.png

Comment 4

[Alex Cornestean]

Attachment: Firefox Screenshots capture.png