It appears that not all hosts which set the transfer-encoding to chunked, actually send the output in chunked format.
An example site of this is http://www.spiritblog.net/ (Purely random selection)
The issue is that WP_Http::chunkTransferDecode() will return false on this event.
I see 2 solutions:
- Have chunkTransferDecode() return the content back if its deterined not to be chunked
- have the transports check that the return result of chunkTransferDecode() is true before assigning to the body.
Option 1 seems a good route honestly, Decode it if its determined to be chunked, else just pass it back. Patch will be attached for this route shortly.