413718 - Warning indicates cache problems: "Never ran into the same child that we started from"

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Aaron Leventhal]

I have seen this warning in the console. This and any other cache warnings need investigation because they lead to problems and potentially crashes.

Comment 1

[Aaron Leventhal]

Attachment: 1) Fix error checking, 2) Fix legit error where we set the first child of an outer doc to null, but don't reset the child's parent

Comment 2

[Mike Beltzner [:beltzner, not reading bugmail]]

Comment on attachment 298858 [details] [diff] [review]
1) Fix error checking, 2) Fix legit error where we set the first child of an outer doc to null, but don't reset the child's parent

a=beltzner for 1.9

Comment 3

[Ginn Chen]

This problem still exists.

Step to reproduce, open 4 empty tabs, and then close the 2nd and 3rd tab.
It might be some problem with nsXULTabAccessible.

I didn't see any impact to user yet.

Comment 4

[Ginn Chen]

It's a problem of the cached children list with async events.

If the children list had not been cached before one child was removed, then when we fires children-changed:remove event, we can't find it in the children list.
Because the children list is lazy generated after the removal.

It doesn't impact AT user, because when AT is running, the children list usually is cached earlier.

Comment 5

[Aaron Leventhal]

There was a crash that the NVDA developers found which involved opening about:blank in tabs. I don't remember the bug number.

Comment 6

[Jason Orendorff [:jorendorff]]

(1.9 triage) Looks like the patch was approved and landed, but didn't fix the bug.

Comment 7

[Ginn Chen]

I think the patch did fix some problems.

Currently, I don't think this bug blocks Firefox 3.

Comment 8

[Aaron Leventhal]

I haven't heard of the NVDA crash in a long time, and haven't seen anything on crash-stats. I think this bug is probably fixed now.

Let's just open up a new bug if we see a problem again. This is just going to linger around the bug database collecting dust.