Don't convert empty body on POST/PUT.

[tim-vandecasteele]

When posting with content type 'application/json' and an empty body, multi_json crashes on the empty string.

[dblock]

This is great, thank you. Could you please update the CHANGELOG as part of the pull, I'll merge it.

Also, I've always been confused whether we should be using .size, .length or something else. Rails implementation of blank? has a pretty clear answer:

def blank?
   respond_to?(:empty?) ? empty? : !self
end

Although we're splitting hair, I think empty? is a more readable way to do a check here.

[tim-vandecasteele]

I agree empty? would be nicer to read, sadly StringIO doesn't support empty?.

[dblock]

Merged, than you.

[adamgotterer]

With this commit I started getting "Fatal error: undefined method 'size' for #Rack::Lint::InputWrapper:0x86d92e8" under certain post circumstances while calling params. Would changing && request.body.size > 0 to && request.content_length do the same thing?

[dblock]

@adamgotterer => in theory this would work as well depending on how request.content_length is constructed. I am down with this change if all specs pass.

[adamgotterer]

The current version would fail if it used the real #body_params method and not a mock. The failure case is when the body is plain text and not json. There is no #size method for a string. The change to #content_length wont break tests (I tried it earlier). But I'll spend a little time over the weekend trying to figure out a better way to test this.