Fix bug 2406.

diff --git a/cmd/lefty/os/unix/io.c b/cmd/lefty/os/unix/io.c
index 9397ec4cab93d56c5c82683e1acea9324bf08396..ddadc8478f539df88e18f73548cfbd52ba312046 100644 (file)
--- a/cmd/lefty/os/unix/io.c
+++ b/cmd/lefty/os/unix/io.c
@@ -37,6 +37,26 @@
 #endif
 #include <netdb.h>
 
+/* AI_NUMERICSERV as a value for the `ai_flags' member
+ * of `struct addrinfo' of header <netdb.h> has only
+ * been available since:
+ *
+ *   POSIX 1003.1-2008, Issue 7
+ *   glibc 2.3.4
+ *   Mac OS X 10.6
+ *   etc.
+ *
+ * Fortunately, its main purpose seems to be only
+ * to optimize calls of `getaddrinfo', and because it
+ * is meant to be a bit flag, it can therefore be
+ * [relatively] safely ignored by defining it to have
+ * the value zero.
+ */
+
+#ifndef AI_NUMERICSERV
+#define AI_NUMERICSERV 0
+#endif
+
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif