Open Bug 1976772 Opened 6 months ago Updated 4 months ago

Stop using mouseleave in tabbrowser/content/tabs.js

Categories

(Firefox :: Tabbed Browser, defect, P2)

Product:
Firefox
Component:
Tabbed Browser
Type:
defect

Tracking

()

Tracking Flags:
Tracking Status
firefox-esr115 --- unaffected
firefox-esr128 --- wontfix
firefox-esr140 --- affected
firefox140 --- wontfix
firefox141 --- wontfix
firefox142 --- wontfix
firefox143 --- fix-optional

People

(Reporter: mccr8, Assigned: dwalker)

References

(Blocks 1 open bug, Regression)

Details

(Keywords: perf, regression)

When running tests in a debug build, a frequent cause of warning messages is "WARNING: Please do not use mouseenter/leave events in chrome. They are slower than mouseover/out!". One test where this occurs frequently is testing/crashtest/final/1419902.html.

I added some logging to determine which places are adding these events, and one of the three most common places is a mouseleave in chrome://browser/content/tabbrowser/tabs.js.

I don't know about events, but if this could be changed to a mouseout that would be good.

Set release status flags based on info from the regressing bug 1876522

:dwalker, since you are the author of the regressor, bug 1876522, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

status-firefox140: --- → affected
status-firefox141: --- → affected
status-firefox142: --- → affected
status-firefox-esr128: --- → affected
status-firefox-esr140: --- → affected
Flags: needinfo?(dwalker)

See bug 1976773 comment 2 for how to handle same things with mouseover and mouseout.

Assignee: nobody → dwalker
Flags: needinfo?(dwalker)

Set release status flags based on info from the regressing bug 1876522

status-firefox143: --- → affected
Severity: -- → S3
Keywords: perf
Priority: -- → P2
See Also: → 1976773
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