NVDA repeats input label text

[stevefaulkner]

when an author codes a HTML label element in certain ways NVDA announces the label text twice when an input receives focus.

I have provided test cases and results here:
 http://www.html5accessibility.com/tests/form-labels.html

[jteh]

For Firefox, this is partially due to  MozillaBug:669312.

There are two other problems here:

1. We're reading labels in the focus ancestry. Mick, is there a reason for this? I can't think of one. It might be because we're just relying on presentationType and we want labels to be content if they are leaf nodes. In that case, we should check childCount or make a special case in isPresentableFocusAncestor.
2. In IE, labels seem to have a role of text instead of label. If we can fix this, (1) will apply to IE as well.

[jteh]

Replying to jteh:

For Firefox, this is partially due to  MozillaBug:669312.

 MozillaBug:682790 is now the relevant bug. The other was closed as a duplicate.

[mdcurran]

Partial fix in changeset:main,4663. Label elements are no longer spoken in both IE and Firefox when focus moves to a control inside of them. Remaining issue of Firefox showing duplicated label in accName must be fixed in Gecko.