Hi,

I am attempting to use megadl on an IPv6-only host, this should work as mega.nz is fully IPv6 enabled.

It first tries to connect to g.api.mega.co.nz, this host does have IPv6 addresses:

# host g.api.mega.co.nz.
g.api.mega.co.nz is an alias for lu.api.mega.co.nz.
lu.api.mega.co.nz has address 66.203.125.13
lu.api.mega.co.nz has address 66.203.125.11
lu.api.mega.co.nz has address 66.203.125.14
lu.api.mega.co.nz has address 66.203.125.12
lu.api.mega.co.nz has address 66.203.125.15
lu.api.mega.co.nz has IPv6 address 2a0b:e46:1:100::14
lu.api.mega.co.nz has IPv6 address 2a0b:e46:1:100::12
lu.api.mega.co.nz has IPv6 address 2a0b:e46:1:100::13
lu.api.mega.co.nz has IPv6 address 2a0b:e46:1:100::11
lu.api.mega.co.nz has IPv6 address 2a0b:e46:1:100::15
However, the tool only attempts to connect to the legacy IPv4 addresses when run with --debug=http:

*   Trying 66.203.125.13:443...
* Immediate connect fail for 66.203.125.13: Network is unreachable
*   Trying 66.203.125.11:443...
* Immediate connect fail for 66.203.125.11: Network is unreachable
*   Trying 66.203.125.14:443...
* Immediate connect fail for 66.203.125.14: Network is unreachable
*   Trying 66.203.125.12:443...
* Immediate connect fail for 66.203.125.12: Network is unreachable
*   Trying 66.203.125.15:443...
* Immediate connect fail for 66.203.125.15: Network is unreachable
* Closing connection 0
Manually accessing mega.nz with curl works as expected over IPv6.

This appears to be caused by the following line in http.c which forces libcurl to only resolve legacy ipv4 addresses:

./lib/http.c:	curl_easy_setopt(h->curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);

by changing it back to the default value, it all works fine:

./lib/http.c:	curl_easy_setopt(h->curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_WHATEVER);