1557581 - minor rendering error in old twitter text editor

Status: NEW

(Core :: Graphics: WebRender, defect, P3)

Description

[Aria Beingessner [:Gankra]]

Attachment: Screen Shot 2019-06-06 at 6.09.07 PM.png

I've noticed this for a while, mostly just assuming it was Twitter Being Bad (it frequently just... breaks). In the attached screenshot, note the line cutting through the "e" in hello. When it happens it will be slightly persistent, although it will sometimes flicker, as if it's a shadow of the cursor?

It doesn't happen all the time, and sometimes I have trouble getting it to happen, but it randomly happens quite frequently over the course of a day.

I can reproduce this in a capture, but interestingly it only reproduces with a saved frame. If I use the arrow keys to generate a new frame, or delete the frame.ron, it doesn't happen. This makes it fairly likely to me that this isn't twitter/gecko saying to draw something there, but rather something in the guts of webrender is messing up.

If I change to a light twitter theme, the line becomes white. This suggests to me that we're just... losing a row of pixels here?

This is on my macbook pro, not sure if it happens elsewhere.

Comment 1

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

The priority flag is not set for this bug.
:jbonisteel, could you have a look please?

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Comment 2

[Glenn Watson [:gw]]

Is this still an issue, and if so, is there a way to repro it locally?

Comment 3

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

Clear a needinfo that is pending on an inactive user.

Inactive users most likely will not respond; if the missing information is essential and cannot be collected another way, the bug maybe should be closed as INCOMPLETE.

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