Gisle Vanem:

Basically in loops like handle_errors(), 'query->next' was assigned a local
variable and then query was referenced after the memory was freed by
next_server(). I've changed that so next_server() and end_query() returns the
next query. So callers should use this ret-value.

The next problem was that 'server->tcp_buffer_pos' had a random value at entry
to 1st recv() (luckily causing Winsock to return ENOBUFS).

I've also added a ares_writev() for Windows to streamline the code
a bit more.

nameser.h

@@ -26,6 +26,9 @@ struct iovec
 
 #define getpid() _getpid()
 
+int ares_writev (SOCKET s, const struct iovec *vector, size_t count);
+#define writev(s,vect,count)  ares_writev(s,vect,count)
+
 struct timezone { int dummy; };
 
 int ares_gettimeofday(struct timeval *tv, struct timezone *tz);