nvda

9d4efc8b - MozillaCompoundTextInfo: cache lastCaretObj for the parent NVDAObject in a WeakKeyDictionary on the TextInfo class, keyed by the parent NVDAObject. This guarantees we only hold it for the lifetime of the parent NVDAObject, but don't have to incorrectly assume that the caret is only fetched while the parent NVDAObject has focus.