I noticed with version 7.33.0 of libcurl I was getting error messages
such as "Operation timed out after 2003 milliseconds with 0 out of -1
bytes received" when using the multi interface. The "out of -1" makes
no sense. This seems to be a regression since 7.16.2 (ancient, I know!
- but stable for many terabytes of JET experimental data over the
years). The attached patch fixes this.

I have not written a specific test case, but if you run

   ./runtests.pl -k 29

and examine log/stderr29 you can see the error message in question.

-- 
Colin Hogben