540389 - WARNING: Bad accessible tree!: file ../../../mozilla-central/accessible/src/base/nsAccessible.cpp, line 2949 [tabbrowser tab]

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Ginn Chen]

2944 #ifdef DEBUG
2945   NS_ASSERTION(!parentAcc->IsDefunct(), "Defunct parent!");
2946 
2947   parentAcc->EnsureChildren();
2948   if (parent != mParent)
2949     NS_WARNING("Bad accessible tree!");
2950 #endif

What kind of error are we trying to detect here?

We do GetAccessibleInParentChain() only if mParent is null, and it seems we didn't do SetParent() here.

Comment 1

[alexander :surkov (:asurkov)]

(In reply to comment #0)
> 2944 #ifdef DEBUG
> 2945   NS_ASSERTION(!parentAcc->IsDefunct(), "Defunct parent!");
> 2946 
> 2947   parentAcc->EnsureChildren();
> 2948   if (parent != mParent)
> 2949     NS_WARNING("Bad accessible tree!");
> 2950 #endif
> 
> What kind of error are we trying to detect here?

we detect a case when an accessible has a parent accessible but this parent accessible hasn't this accessible in children.

> 
> We do GetAccessibleInParentChain() only if mParent is null, and it seems we
> didn't do SetParent() here.

and that's a problem.

Comment 2

[Ginn Chen]

(In reply to comment #1)
> > What kind of error are we trying to detect here?
> 
> we detect a case when an accessible has a parent accessible but this parent
> accessible hasn't this accessible in children.

Thanks, I must misread the code when I raise the question.

So the problem is why nsXULTabAccessible hasn't nsXULToolbarButtonAccessible in its children.

Comment 3

[alexander :surkov (:asurkov)]

(In reply to comment #2)

> So the problem is why nsXULTabAccessible hasn't nsXULToolbarButtonAccessible in
> its children.

It sounds tab has close button and tab accessible doesn't allow accessible anonymous children.

Comment 4

[alexander :surkov (:asurkov)]

Attachment: wip

Comment 5

[alexander :surkov (:asurkov)]

Attachment: patch

Comment 6

[alexander :surkov (:asurkov)]

try server build - https://build.mozilla.org/tryserver-builds/[e-mail]-try-1a24991ea114/

Comment 7

[David Bolter [:davidb] (NeedInfo me for attention)]

Comment on attachment 422197 [details] [diff] [review]
patch

r=me for the /accessible part, let's make sure taking those nodes out of our tree via role=presentation doesn't break anything before landing.

Does this get rid of all those warnings?

Comment 8

[Marco Zehe (:MarcoZ)]

Comment on attachment 422197 [details] [diff] [review]
patch

r=me. Thanks!

Comment 9

[alexander :surkov (:asurkov)]

Mike, toolkit and browser changes are pure a11y changes, I added role="presentation" on elements that shouldn't be exposed to AT.

Comment 10

[Mike Connor [:mconnor]]

Comment on attachment 422197 [details] [diff] [review]
patch

What you really want is review from a peer for browser/toolkit, this doesn't really change anything wrt APIs and such, so SR isn't required, but i can give you review+ for those bits, so you're good to go.

Comment 11

[alexander :surkov (:asurkov)]

Yes, thank you.

Comment 12

[alexander :surkov (:asurkov)]

landed on 1.9.3 - http://hg.mozilla.org/mozilla-central/rev/3198c740b660

Comment 13

[David Bolter [:davidb] (NeedInfo me for attention)]

I'm still getting the warnings unfortunately (dumped to terminal during a11y mochitests run).

Comment 14

[alexander :surkov (:asurkov)]

Really? Tabbrowser fails? If no then please file another bug because I don't want to keep one bug for every wrong creation of accessible tree.

Comment 15

[Ginn Chen]

Close this one and clone it for the new bug.

Comment 16

[alexander :surkov (:asurkov)]

David, could you please look if errors you get are different from Ginn's ones described in bug 541039 and if so then file new bug?

Comment 17

[David Bolter [:davidb] (NeedInfo me for attention)]

Alexander, I'm getting the same warning described by this bug.
WARNING: Bad accessible tree!: file /Users/dtb/mozworkspace/src/accessible/src/base/nsAccessible.cpp

You don't get them?

Comment 18

[alexander :surkov (:asurkov)]

(In reply to comment #17)
> Alexander, I'm getting the same warning described by this bug.
> WARNING: Bad accessible tree!: file
> /Users/dtb/mozworkspace/src/accessible/src/base/nsAccessible.cpp

Do you get it because toolbarbutton is not a child of tab? 

This assertion is kind of common assertion. It's not good idea to keep one bug for all broken tree cases. Please stop debugger when you get an assertion and look who is child and who is parent. If we don't have a bug for your case then please file new one.

Comment 19

[David Bolter [:davidb] (NeedInfo me for attention)]

OK