help with Mount::GeneratableRegexp#generate

[Hez Ronningen <hronningen@gmail.com>]

Hello,

rails ver: 3.0.0
rack (1.2.1)
rack-mount (0.6.13)
rack-cache (0.5.3)

I've been digging around in the internals of the router for a while trying to diagnose a strange behaviour. On most pages our links are generated with url_for and it works well, but on one page it generates a very confusing url. These urls are in the application layout so the code is pretty much the same.

example good url:
http://localhost:3000/quick-links/about-us

example bad url:
http://localhost:3000/pages/20?path[]=quick-links&path[]=about-us

I ended up digging all the way in to the GeneratableRegexp and found that the difference between the urls is in the malformed one a recall hash is passed in. I have found a line of code where I think the problem originates from...
Line ~55
merged = recall.merge(params)

What happens here is the recall hash is merged with the destination urls hash. What happens next is key, the GeneratableRegexp tries to see if all the requirements have been meet for this route. But we have contaminated the data with params from the recall url, so variables that weren't in the original destination url are used in the check and in the generation process.

I'm not sure the solution here, any ideas?

Cheers,
Hez