416753 - Crashes in GetState()

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Aaron Leventhal]

I have seen at least 1 place where we crash in GetState(), because we now return NS_OK when !mDOMNode, because it's a legitimate time to return EXT_STATE_DEFUNCT

http://crash-stats.mozilla.com/report/index/ea728a75-d7eb-11dc-b0be-001a4bd43ed6

We may just be seeing this now because of the fix to bug 381049, and the crash occurs during a call to get_accState().

Also, Marco mentioned that his empty Thunderbird content issue was due to an access violation in get_accState(). So this might be the fix for bug 405951.

Comment 1

[Aaron Leventhal]

Attachment: We have fixed some of these before, but apparently missed a few

Comment 2

[alexander :surkov (:asurkov)]

I would add new NS_OK value for defunct state (like we did for NS_OK_NO_ARIA_VALUE) to have unique way of checking.

Comment 3

[Aaron Leventhal]

That would be a big change, can we do that after Firefox 3? I'm not up for it right now :/

Comment 4

[alexander :surkov (:asurkov)]

(In reply to comment #3)
> That would be a big change, can we do that after Firefox 3? I'm not up for it
> right now :/
> 

Ok, then could you file bug for this? ;)

Comment 5

[alexander :surkov (:asurkov)]

Comment on attachment 302509 [details] [diff] [review]
We have fixed some of these before, but apparently missed a few


> NS_IMETHODIMP
> nsHTML4ButtonAccessible::GetState(PRUint32 *aState, PRUint32 *aExtraState)
> {
>-  nsCOMPtr<nsIDOMElement> element(do_QueryInterface(mDOMNode));
>-  NS_ENSURE_TRUE(element, NS_ERROR_FAILURE);  // Button accessible shut down
>-
>   nsresult rv = nsHyperTextAccessibleWrap::GetState(aState, aExtraState);
>   NS_ENSURE_SUCCESS(rv, rv);
>+  if (!mDOMNode)
>+    return NS_OK;
>+
>+  nsCOMPtr<nsIDOMElement> element(do_QueryInterface(mDOMNode));
>+  NS_ENSURE_TRUE(element, NS_ERROR_FAILURE);  // Button accessible shut down

I think it's overkill. And it seems wrong comment


with that addressed r=me

Comment 6

[Marco Zehe (:MarcoZ)]

I just ran with this patch, and it does not appear to fix my Thunderbird crash from bug 405951 yet.