Informix visitor ignores joins

[jhollinger]

Using Arel 3.0.2 with Rails 3.2, but I believe the bug has always been present. A joined query like Comment.joins("inner join posts on post.id = comments.post_id").where("posts.published = 1") results in the invalid sql statement select * from comments where posts.published = 1.

It's a one-line patch to visit_Arel_Nodes_SelectCore in lib/arel/visitors/informix.rb:

- ("FROM #{visit o.froms}" if o.froms),
+ ("FROM #{visit o.source}" if o.source),

I plan to fork and submit a pull request soon, unless someone can point out a problem with that solution.

[tenderlove]

Looks good. I'll close this and wait for a pull request from you. Please make sure to include a test so that I don't break it in the future! Thank you.