They result in a page with Google complaining that the link is not valid.
However, if I go ask for a shareable link from the same Google Doc, the link works.
Can you provide examples here?
For example:
A public google doc shared from a Google Apps account (beta.nyc) that doesn’t work. It appears that Discourse url encodes the ? for the edit URL parameter.
It doesn’t happen on the get a shareable link version of the same doc.
As markdown link - form 1
As markdown link - form 2
Strange… it works here…
Never mind, it was a user error 
I double-checked the user’s posting, and he must have mangled the URLs when he C&Ped from the browser:
Note the %23 for the URL parm. BTW, does Discourse handle percent-encoded links? (say %20 for embedded spaces)