From c179d9a57b41f353b58555e70efa310581bced60 Mon Sep 17 00:00:00 2001
From: Michael Santos <michael.santos@gmail.com>
Date: Sun, 17 Jun 2018 10:01:44 -0400
Subject: [PATCH] start_listen_sockets: exit if no addresses

Do not allocate a 0 byte buffer if no addresses are available:

    common.c:122:14: warning: Call to 'malloc' has an allocation size of 0 bytes
       *sockfd = malloc(num_addr * sizeof(*sockfd[0]));
		 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
---
 common.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/common.c b/common.c
index ca17354..378eb9a 100644
--- a/common.c
+++ b/common.c
@@ -116,6 +116,11 @@ int start_listen_sockets(int *sockfd[], struct addrinfo *addr_list)
    for (addr = addr_list; addr; addr = addr->ai_next)
        num_addr++;
 
+   if (num_addr == 0) {
+       fprintf(stderr, "FATAL: No available addresses.\n");
+       exit(1);
+   }
+
    if (verbose)
        fprintf(stderr, "listening to %d addresses\n", num_addr);