1789667 - The background images from the "about:welcome" page are no longer visible if the "High Contrast" mode is active

Status: VERIFIED FIXED

(Firefox :: Messaging System, defect, P1)

Description

[Marius Coman [:mcoman], Ecosystem QA]

Attachment: rec of the issue.gif

[Windows] The background images from the "about:welcome" page are no longer visible if the "High Contrast" mode is active

[Notes]:

• This issue is reproducible only on Windows.
• This issue is not reproducible on the existing users Onboarding modals.

[Affected versions]:

• Firefox Nightly 106.0a1 - Build ID: 20220907093209

[Affected Platforms]:

• Windows 10 x64

[Prerequisites]:

• Have the following prefs in the "about:config" page:
• devtools.chrome.enabled set to true
• Have the system's "High Contrast" mode active.

[Steps to reproduce]:

1. Open the browser with the profile from the prerequisites and navigate to the "about:welcome" page.
2. Navigate through the "Onboarding" screens and observe the background images.

[Expected result]:

• The background images are visible.

[Actual result]:

• The background images are NOT visible.

[Additional Notes]:

• Attached a screen recording of the issue.

Comment 1

[Shane Hughes [:aminomancer]]

Attachment: Bug 1789667 - Fix onboarding screen background images for HCM. r=mviar

In HCM on Windows, background colors are overridden by the HCM theme's
default background value. And if a CSS background property has more
than 1 layer, only the last layer can include a background-color, so I
suspect that if it has one, background-images on the previous layers
will be obscured by the overridden default background on the last
layer. This patch circumvents this by putting the background-color on
the same layer as the background-image.

Comment 2

[Shane Hughes [:aminomancer]]

The issue reproduces on macOS for me. Haven't tried on Linux

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4fd8069963b3
Fix onboarding screen background images for HCM. r=mviar,emcminn

Comment 4

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/4fd8069963b3

Comment 5

[Marius Coman [:mcoman], Ecosystem QA]

I have verified this issue with the latest Firefox Nightly (106.0a1 Build ID - 20220914213649) installed on Windows 10 x64, macOS 11.6.7, and Linux Mint 20.2 x64. Now, I can confirm that the image asset is visible if the HCM is active. However, during testing, I have observed that the image background is not visible if the system HCM is active, but I have logged a separate issue for that (see Bug 1791010).