1958728 - Some emails have a dark background if the system is in dark mode, even if message dark mode is disabled

Status: RESOLVED FIXED

(Thunderbird :: Mail Window Front End, defect)

Description

[Sky Schubert [:skyschub]]

Attachment: example-email.png

I am on macOS, with the system (and thus Thunderbird) in dark mode, but my mail content is explicitly not in dark mode - the "Enable dark message mode" checkbox is not set, and the dark mode toggle is in "light mode". This is deliberate on my end, because a lot of mails don't work in dark mode, so I just want the mail content to be "light mode", even with the chrome in dark mode.

Despite my "light mode" settings, lots of HTML-emails now have a dark background, and all plain text mails have a dark theme. This is making a lot of mails harder to read or near impossible to read, because the font color isn't adjusted - I've attached a screenshot of an email.

mozregression pointed me to this push, so I'm fairly sure this is a regression of bug 1957508.

Comment 1

[Kagami Rosylight 🏳️‍🌈🏳️‍⚧️ [:saschanaz] (they/them)]

The right solution should probably toggle color-scheme: dark following the light/dark toggle switch.

Comment 2

[Richard Marti (:Paenglab)]

Martin, is it possible (if yes, how?) to inject the style color-scheme from here to the message? As I know the message is protected from external access which could make it complicated.

Comment 3

[Martin Giger [:freaktechnik]]

Since that's controlled by prefs, I wonder if we could actually use pref media queries to apply the better matching color scheme. Though it's possible that the stylesheet we use isn't "low level" enough to get to do that.

Comment 4

[Richard Marti (:Paenglab)]

Attachment: Bug 1958728 - Apply the color-scheme only when dark reader is enabled. r=#thunderbird-front-end-reviewers

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/0e98866f1c64
Apply the color-scheme only when dark reader is enabled. r=freaktechnik,aleca

Comment 6

[Richard Marti (:Paenglab)]

Comment on attachment 9477438 [details]
Bug 1958728 - Apply the color-scheme only when dark reader is enabled. r=#thunderbird-front-end-reviewers

Flag not set.

Comment 7

[Richard Marti (:Paenglab)]

Comment on attachment 9477438 [details]
Bug 1958728 - Apply the color-scheme only when dark reader is enabled. r=#thunderbird-front-end-reviewers

Uplift Approval Request

• Please state case for uplift consideration and ensure bug severity is set: On dark system with light TB theme the message reader shows still in dark mode.
• User impact if declined: Wrong message reader color scheme.
• Is this code covered by automated tests?: No
• Has the fix been verified in Daily?: Yes
• Has the fix been verified in Beta?: N/A
• Needs manual test from QA?: No
• If yes, steps to reproduce:
• List of other uplifts needed: Bug 1957508
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Small CSS change
• String changes made/needed: no

Comment 8

[Corey Bryant]

Comment on attachment 9477438 [details]
Bug 1958728 - Apply the color-scheme only when dark reader is enabled. r=#thunderbird-front-end-reviewers

[Triage Comment]
Approved for beta

Comment 9

[Corey Bryant]

Thunderbird 138.0b2:
https://hg.mozilla.org/releases/comm-beta/rev/2fdd72cfaa77