dojo.undo.browser breaks in ambiguous situations

[adam@…]

Given a page index.html which uses dojo.undo.browser to change urls, if a user visits:

(1) index.html#a (2) index.html#b (3) index.html#c (4) index.html#b

in that order, then presses back three times, the third back will not affect the page.

What happens is that dojo correctly interprets the first back as a movement from (4) to (3), but then misinterprets the second back as a forward (since (2) and (4) are the same url), and assumes we are now at (4). When the user presses back a third time, dojo cannot work out how we reached (1), and thus doesn't call a state handler.

[blowery]

Sadly we're limited by the browsers here. They (at least firefox / safari) don't deal with the hash as a history marker in more than one place in a sane manner, so we can't really either. Won't fix for now, unless someone comes up with something brilliant to work around the problem.