From f73ee9d3528aa7313553116d32c3980a57e52a74 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Fri, 21 Aug 2015 09:29:38 -0600
Subject: [PATCH] apps/system/netdb would not build unless
 CONFIG_NETDB_HOSTFILE was defined because it needed gethostbyname.  Noted by
 OrbitalFox

---
 ChangeLog.txt             |  5 +++++
 system/netdb/netdb_main.c | 13 +++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index 9b205521c..cb47161df 100755
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -1400,4 +1400,9 @@
 	  command line options (2015-08-17).
 	* apps/examples/usbserial: Can now be run as an NSH builtin-function.
 	  Now uses a configurable IO buffer size (2015-08-20).
+	* Various Kconfig files in netutils:  Fix some changes from from
+	  NETUTILS_DNSCLIENT to NETDB_DNSCLIENT.  From Pavel Pisa (2015-08-20).
+	* system/netdb:  Failed to build if CONFIG_NET_HOSTFILE was not defined
+	  because gethostbyaddr() was not available.  Noted by OrbitalFox
+	  (2015-08-21).
 
diff --git a/system/netdb/netdb_main.c b/system/netdb/netdb_main.c
index c195ad34d..4c0872179 100644
--- a/system/netdb/netdb_main.c
+++ b/system/netdb/netdb_main.c
@@ -65,6 +65,15 @@
 #  define CONFIG_SYSTEM_NETDB_PRIORITY 50
 #endif
 
+/* REVIST: Currently the availability of gethostbyaddr() depends on
+ * CONFIG_NETDB_HOSTFILE.  That might not always be true, however.
+ */
+
+#undef HAVE_GETHOSTBYADDR
+#ifdef CONFIG_NETDB_HOSTFILE
+#  define HAVE_GETHOSTBYADDR 1
+#endif
+
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -73,8 +82,10 @@ static void show_usage(FAR const char *progname, int exitcode) noreturn_function
 static void show_usage(FAR const char *progname, int exitcode)
 {
   fprintf(stderr, "USAGE: %s --ipv4 <ipv4-addr>\n", progname);
+#ifdef HAVE_GETHOSTBYADDR
   fprintf(stderr, "       %s --ipv6 <ipv6-addr>\n", progname);
   fprintf(stderr, "       %s --host <host-name>\n", progname);
+#endif
   fprintf(stderr, "       %s --help\n", progname);
   exit(exitcode);
 }
@@ -110,6 +121,7 @@ int netdb_main(int argc, char **argv)
       show_usage(argv[0], EXIT_FAILURE);
     }
 
+#ifdef HAVE_GETHOSTBYADDR
   /* Handle: netdb --ipv4 <ipv4-addr>  */
 
   else if (strcmp(argv[1], "--ipv4") == 0)
@@ -161,6 +173,7 @@ int netdb_main(int argc, char **argv)
           return EXIT_FAILURE;
         }
     }
+#endif /* HAVE_GETHOSTBYADDR */
 
   /* Handle: netdb --host <host-name>  */