net/http: ParseMultipartForm should populate PostForm with field values

[opennota]

Currently ParseMultipartForm() appends values to the request's Form only: http://play.golang.org/p/OHN6v9z7-P

Whereas, the docs for PostFormValue() say, that it calls ParseMultipartForm():

PostFormValue returns the first value for the named component of the POST or PUT request body.
URL query parameters are ignored. PostFormValue calls ParseMultipartForm and ParseForm if
necessary and ignores any errors returned by these functions.

But PostForm remains empty, and PostFormValue() returns an empty string. I think that's illogical. I'd expect it to add form fields values to the request's PostForm. It is a POST request, after all.

[bradfitz]

I suppose we could put it in both places.

[rsc]

Too late for Go 1.5.

[gopherbot]

CL https://golang.org/cl/19986 mentions this issue.