2069280 - Fix the undefined --border-color-dead-row custom property in aboutMemory.css

Status: RESOLVED FIXED

(Toolkit :: about:memory, task)

Description

[Dão Gottwald [:dao]]

Filing as a good first bug to learn workflows.

.nodeInspector .deadRow in toolkit/components/aboutmemory/content/aboutMemory.css sets border: var(--border-color-dead-row), but nothing defines --border-color-dead-row. The declaration is dropped at computed-value time, so dead rows in about:memory's Collector Log Analyzer render with no border.

Bug 2005954 added the rule with a mismatched pair of names: the custom property was defined as --background-color-dead-row while the use site read --border-color-dead-row, so the two never met. Because the defined name was never referenced, browser_parsable_css.js failed, and the follow-up fix removed the definition rather than reconciling the names, which left the use site pointing at nothing.

The value belongs to the border shorthand rather than to a colour, so name it for what it is. Add the property back beside its siblings in the same rule (near --background-color-grid-header):

--border-dead-row: 1px solid color-mix(in srgb, var(--color-gray-60) 30%, transparent);

and change the use site to match:

border: var(--border-dead-row);

Link to the code:
https://searchfox.org/firefox-main/source/toolkit/components/aboutmemory/content/aboutMemory.css

The change is recent enough that Searchfox may not have indexed it yet. To find both places locally:

grep -n "dead-row\|background-color-grid-header" toolkit/components/aboutmemory/content/aboutMemory.css

To verify the fix:

./mach lint -l stylelint toolkit/components/aboutmemory/content/aboutMemory.css
./mach test browser/base/content/test/static/browser_parsable_css.js

The second one is the guard that caught the original mistake: it fails on a custom property nothing references, so it confirms the new name is actually used.

Then check that the styling applies: open about:memory, load a cycle-collector log in the Collector Log Analyzer, and confirm in the Browser Toolbox inspector that .nodeInspector .deadRow has a border instead of a dropped border declaration.

Tutorial to contribute:
https://firefox-source-docs.mozilla.org/contributing/contribution_quickref.html
https://firefox-source-docs.mozilla.org/contributing/stack_quickref.html

Please don't ask for the bug to be assigned. It will be automatically assigned to the first patch.

Comment 1

[Xiaosen Zhuang]

Hi! I'd like to work on this as my first Firefox contribution. Could you assign it to me?

Comment 2

[Itiel]

(In reply to Xiaosen Zhuang from comment #1)

Hi! I'd like to work on this as my first Firefox contribution. Could you assign it to me?

See the last paragraph on the bug description.

Comment 3

[Xiaosen Zhuang]

Attachment: Bug 2069280 - Define --border-dead-row for dead rows in about:memory's Collector Log Analyzer r=dao

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/7e1e37f5ef08
https://hg.mozilla.org/integration/autoland/rev/08f81cc253ed
Define --border-dead-row for dead rows in about:memory's Collector Log Analyzer r=dao,desktop-theme-reviewers DONTBUILD

Comment 5

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/08f81cc253ed