Dialogs that appear when a control is activated in MSHTML virtual buffer cause freeze

[jteh]

In Internet Explorer (and I assume anything that uses the MSHTML DOM), when enter is pressed on an element that presents a dialog box, NVDA freezes until the dialog is dismissed. This does not occur in Gecko. This is caused by the click() method on DOM nodes blocking until the dialog is dismissed. There are two possible solutions:

1. Find another method to click these controls; or
2. Spawn another thread to click the control.

I'm not sure whether option 1 is possible. We could perhaps do this with the mouse if there is no alternative method on the DOM nodes. Option 2 is not difficult, but it is a bit evil and should be a last resort.

I know we weren't going to implement any virtual buffer fixes, but this is a really troublesome issue. If the fix is not trivial, we should delay this until after 0.5, but I think it would be good to fix this in 0.5 if we can.

You can reproduce this with a link like this:

<a href="foo" onClick="alert('test');">foo</a>