curl: 55: Heap-buffer-overflow read in `curl_formadd_ccsid()` with binary form data

Summary curlformaddccsid in projects/OS400/ccsidcurl.c performs a heap-buffer-overflow read when CURLFORMCONTENTTYPE appears before an explicit length CURLFORMCONTENTLEN / CURLFORMCONTENTSLENGTH for binary CURLFORMCOPYCONTENTS data containing embedded NUL bytes. The overread bytes are copied into...