382318 - crash [@ nsXULTreeAccessibleWrap::GetColumnAtIndex]

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Ginn Chen]

Open orca
Open some webpages, e.g. Minefield homepage, Google homepage.

Crashed.

accessible/src/atk/nsXULTreeAccessibleWrap.cpp

265   *_retval = (aIndex - treeCols) % columns;
266   
267   return NS_OK;

aInde =1, treeCols = 1
columns = 0

Comment 1

[Ginn Chen]

Maybe this is related to URL field autocomplete?

nsXULTreeAccessibleWrap::GetColumns calls nsAccessible::GetChildCount and got 0 for mAccChildCount

Comment 2

[[e-mail]]

Could GetColumns be returning 0 because the popup hasn't been displayed yet and so doesn't have all the right accessibles?

Comment 3

[Ginn Chen]

maybe.
I don't need open web pages to reproduce this bug now.
just drop down URL autocomplete several times, and shift focus in items with mouse.

see also bug 359845. could be a similar cause.

Comment 4

[Ginn Chen]

correction:
to reproduce this bug, you need to drop down URL autocomplete, and click one url, try several times while orca open

GetRowCount works fine
mFirstChild->GetChildCount(&colCount); got 0 (mFirstChild is nsXULTreeColumnsAccessibleWrap)

This nsXULTreeColumnsAccessible has no accessible child, because anything in it is invisible.
(xul:hbox class="tree-scrollable-columns" and xul:treecolpicker)

Comment 5

[Ginn Chen]

1287   // Check frame to see if it is hidden
1288   if (!frame || !frame->GetStyleVisibility()->IsVisible()) {
1289     *aIsHidden = PR_TRUE;
1290   }

I got aIsHidden = PR_TRUE for treecols children when autocomplete is opening/closing popup.

Should we create accessible for cols children despite hidden at that time?

Comment 6

[Ginn Chen]

Attachment: patch

patch to avoid crash

Comment 7

[Ginn Chen]

autocomplete tree is collapsed during popup, and is hidden during close popup.

We didn't create accessibles for cols in these case.

I doubt we should also change
1288   if (!frame || !frame->GetStyleVisibility()->IsVisible()) {
to
1288   if (!frame || !frame->GetStyleVisibility()->IsVisibleOrCollapsed()) {

or check content parent tag equals treecols

I also noticed we get row count from mTreeView->GetRowCount, does it care collapesd or hidden?