MSHTML virtual buffer isAlive property: There are no longer any states that we can...

This kills the buffer, thereby preventing further queries.
In IE 8 on Windows XP, this stops freezes when moving around in the system menu because the frozen buffer isn't being queried for info on every focus change.
Fixes #1577.

diff --git a/source/virtualBuffers/MSHTML.py b/source/virtualBuffers/MSHTML.py
index 1434fa3..b646a12 100644 (file)
--- a/source/virtualBuffers/MSHTML.py
+++ b/source/virtualBuffers/MSHTML.py
@@ -171,6 +171,9 @@ class MSHTML(VirtualBuffer):
                root=self.rootNVDAObject\r
                if not root:\r
                        return False\r
+               if not root.IAccessibleRole:\r
+                       # The root object is dead.\r
+                       return False\r
                states=root.states\r
                if not winUser.isWindow(root.windowHandle) or controlTypes.STATE_EDITABLE in states:\r
                        return False\r