1693886 - data uri doesn't work in var() references if they go over 1mb

Status: VERIFIED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Steve.Olson05]

Attachment: ff_base64url.pdf

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:85.0) Gecko/20100101 Firefox/85.0

Steps to reproduce:

The background image at https://stolson.com works fine on Chrome, Safari, and mobile Firefox as it uses a base64 encoded image URL passed as a CSS variable.

Could be related to this Chromium issue: https://bugs.chromium.org/p/chromium/issues/detail?id=61816

Actual results:

Firefox does not load the image (sorry if this isn't enough detail) when passed as a css variable, ex. --imageUrl:url(data:image/jpeg;base64/9j/4AA...)

Expected results:

Load the image.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::PDF Viewer' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Timea Cernea [:tbabos][inactive]]

Reproduced on MacOS 10.15 on all latest Firefox versions. This could also be an old regression as it worked back in November 2018, pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=f2915d3ee5f8705676e4bb643eab54b62246f25f&tochange=6453222232be364fb8ce3fd29b6cbcd480e5f2e3

Unfortunately, mozregression wouldn't go further than that... Setting up regressionwindows-wanted flag in case someone could continue from where I got blocked.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

We have a 1mb custom property size limit (see bug 1510862). I guess this page is going over that limit somehow. data: uris are not relative URIs btw :)

So... I guess we could increase this limit somewhat. Chrome has also implemented a limit for this so I wonder how different it is.

Comment 4

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1693886 - Increase custom property size limit a bit. r=#style

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/09045a640658
Increase custom property size limit a bit. r=xidorn

Comment 6

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/09045a640658

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:emilio, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment 8

[Emilio Cobos Álvarez (:emilio)]

Comment on attachment 9204592 [details]
Bug 1693886 - Increase custom property size limit a bit. r=#style

Beta/Release Uplift Approval Request

• User impact if declined: data uris of over a megabyte won't work in custom properties.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: comment 0
• List of other uplifts needed: none
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Just increase a limit to allow larger CSS variables.
• String changes made/needed: none

Comment 9

[(PTO June 19-July 7) Ryan VanderMeulen]

Comment on attachment 9204592 [details]
Bug 1693886 - Increase custom property size limit a bit. r=#style

Approved for 87.0b4.

Comment 10

[(PTO June 19-July 7) Ryan VanderMeulen]

https://hg.mozilla.org/releases/mozilla-beta/rev/3d76192472c3

Comment 11

[Catalin Sasca, Desktop Test Engineering [:csasca]]

Reproduced the issue on Firefox Nightly 87.0a1 (2021-02-19) under macOS 10.15.7 by using the STR from Comment 0.

The issue is fixed on Firefox 87.0b4 and Nightly 88.0a1 (2021-02-28). Tests were performed on macOS 10.15.7, Windows 7 and Ubuntu 20.04