1) the dns_cache_timeout should be an integer, not a bool

2) in the curl_dns_cache_entry structure, timestamp should be
a time_t instead of an integer (although I doubt it matters).

lib/hostip.c

@@ -95,7 +95,7 @@ void Curl_global_host_cache_dtor(void)
 
 struct curl_dns_cache_entry {
   Curl_addrinfo *addr;
-  int            timestamp;
+  time_t timestamp;
 };
 
 Curl_addrinfo *Curl_resolv(struct SessionHandle *data,

lib/urldata.h

@@ -617,6 +617,8 @@ struct UserDefined {
   char *krb4_level; /* what security level */
   struct ssl_config_data ssl;  /* user defined SSL stuff */
 
+  int dns_cache_timeout; /* DNS cache timeout */
+  
 /* Here follows boolean settings that define how to behave during
    this session. They are STATIC, set by libcurl users or at least initially
    and they don't change during operations. */
@@ -647,7 +649,6 @@ struct UserDefined {
   bool ftp_use_epsv;     /* if EPSV is to be attempted or not */
 
   bool global_dns_cache;
-  bool dns_cache_timeout;
 };
 
 /*