When resolv.conf contains a single IPv6 nameserver, and the rotate option, the resolver correctly send the requests, but ignore all the answers.
This is due to the initialization of the maps in res_send.c(__libc_res_nsend). For IPv6 nameservers, the map is already initialized, so with a single nameserver, the code creates a second one.
When the rotate option is activated, the nameservers are swapped, which means the first one is the non-existing one.
A patch to fix that is attached.
Created attachment 6418 [details]
Potential fix, based on code from Aurelien
Patch is no good.
After further investigation and testing the problems I'm aware of with the rotate option are all resolved with the patch attached to 13028.
*** This bug has been marked as a duplicate of bug 13028 ***