Is there a way to ignore part of a querystring if it contains the parameter "action"?
We have a 3rd party site which returns to one of our sites and they append "&action=something" to the querystring. The 3rd party site are not able to remove this parameter, so when the user gets returned to our site they're greeted with a 404 page - the Craft docs suggest 'action' is used to determin an action controller to use, which in this case there is not one set.
My 'hack' of an idea would be to detect the parameter in a template, remove that parameter, then go to the url without the 'action' parameter set. This would add more page requests, which would be annoying for a user I can imagine.