1380684 - stylo: Intermittent overlapping text in Facebook comments

Status: RESOLVED WORKSFORME

(Core :: CSS Parsing and Computation, defect, P3)

Description

[Josh Matthews [:jdm]]

Attachment: Screen Shot 2017-07-13 at 11.11.29 AM.png

Intermittently when I open up Facebook, I see comments that have black sans-serif text overlapping the account names. When I hover over the comment section they all restyle correctly.

Comment 1

[Josh Matthews [:jdm]]

The inspector shows that the "Manage" text comes from the "Hide or embed this" link that appears on hover to the right of each comment.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Quick question, does it also go away if we recascade instead of restyle the whole thing? That is, if you resize the window instead of hover over the link? (don't have facebook so it's going to be hard-ish to repro for me... Though I think I've seen something similar in GH too)

Comment 3

[Josh Matthews [:jdm]]

Yes, resizing the window makes it disappear as well.

Comment 4

[Emilio Cobos Álvarez (:emilio)]

I bet this is because the element isn't styled, and we're returning the default computed values for it, which is, default-color 16px sheriff text...

I've opened bug 1380789 to try to uplift the assertions to nightly, in order to see whether we can catch some good STR for them.

Comment 5

[Hiroyuki Ikezoe (:hiro)]

(In reply to Emilio Cobos Álvarez [:emilio] from comment #4)
> I bet this is because the element isn't styled, and we're returning the
> default computed values for it, which is, default-color 16px sheriff text...

It sounds like bug 1374175. In release builds, the panic does not happen, the default values are used.

Comment 6

[Hiroyuki Ikezoe (:hiro)]

Wrong bug. Bug 1371450, I meant.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

(In reply to Hiroyuki Ikezoe (:hiro) from comment #6)
> Wrong bug. Bug 1371450, I meant.

Ok, let's wait for that bug to land if it's known to cause the assertions then, don't want to be crashing all over the place :)

Comment 8

[Hiroyuki Ikezoe (:hiro)]

Does this still happen?  If so, this will be fixed by bug 1381431.