urldata: make magic be the first struct field #6484
By making the
Such mixups can't be detected at compile-time due to them being
By making the `magic` identifier the same size and at the same place within the structs (easy, multi, share), libcurl will be able to more reliably detect and safely error out if an application passes in the wrong handle to APIs. Easier to detect and less likely to cause crashes if done. Such mixups can't be detected at compile-time due to them being typedefed void pointers - unless `CURL_STRICTER` is defined.