Accessing Tempfile after GC of UploadedFile will cause IOError

[kyori19]

In PR #180, @tempfile of Rack::Test::UploadedFile will be unlinked after GC, though we can get direct reference to it.

This script can reproduce the problem. (name this as test.rb and run by ruby ./test.rb)

require 'rack/test/uploaded_file'

def create_uploaded_file(path)
  file = Rack::Test::UploadedFile.new(path)
  file.tempfile
end

tempfile = create_uploaded_file('./test.rb')
GC.start
p tempfile    # => #<Tempfile: (closed)>
tempfile.read # => `read': closed stream (IOError)

To fix this, I think we should stop providing access to the @tempfile and return self for #tempfile method instead. Rack::Test::UploadedFile will delegate all missing methods to @tempfile, so it won't break anything.

[jeremyevans]

This would not be backwards compatible. case Rack::Test::UploadedFile.new.tempfile behavior would change at least.

I don't understand why a finalizer is used in Rack::Test::UploadedFile, considering that Tempfile itself closes and unlinks the internal file whenever it is GCed, and has since Ruby 1.8.7 at least. Seems like nobody involved in #180 understood that. I'll submit a pull request to remove the finalizer.

[kyori19]

Thanks, it should resolve the problem too.