could very well cause a negate number get passed in and thus cause reading
outside of the array usually used for this purpose.
We avoid this by using the uppercase macro versions introduced just now that
does some extra crazy typecasts to avoid byte codes > 127 to cause negative
int values.
linked separately by the application. This function is not provided by the
libcurl API. It can only be accessed by apps if they compile and use this
particular source code.
