Implement github PR #1736

This fixes leak issues on *BSD systems, as described in the PR.

Author: weltling

ext/standard/config.m4

@@ -401,6 +401,7 @@ dnl Detect library functions needed by php dns_xxx functions
 dnl ext/standard/php_dns.h will collect these in a single define: HAVE_FULL_DNS_FUNCS
 dnl
 PHP_CHECK_FUNC(res_nsearch, resolv, bind, socket)
+PHP_CHECK_FUNC(res_ndestroy, resolv, bind, socket)
 PHP_CHECK_FUNC(dns_search, resolv, bind, socket)
 PHP_CHECK_FUNC(dn_expand, resolv, bind, socket)
 PHP_CHECK_FUNC(dn_skipname, resolv, bind, socket)

ext/standard/php_dns.h

@@ -32,9 +32,15 @@
 #elif defined(HAVE_RES_NSEARCH)
 #define php_dns_search(res, dname, class, type, answer, anslen) \
 			res_nsearch(res, dname, class, type, answer, anslen);
+#if HAVE_RES_NDESTROY
+#define php_dns_free_handle(res) \
+			res_ndestroy(res); \
+			php_dns_free_res(res)
+#else
 #define php_dns_free_handle(res) \
 			res_nclose(res); \
 			php_dns_free_res(res)
+#endif
 
 #elif defined(HAVE_RES_SEARCH)
 #define php_dns_search(res, dname, class, type, answer, anslen) \