Get tests working on systems that only support IPv6.

webrtc/base/nethelpers.cc

 /*
  *  Copyright 2008 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 123 matching lines @@
 }
 
 int inet_pton(int af, const char* src, void *dst) {
 #if defined(WEBRTC_WIN)
   return win32_inet_pton(af, src, dst);
 #else
   return ::inet_pton(af, src, dst);
 #endif
 }
 
+bool HasIPv4Enabled() {
+#if defined(WEBRTC_POSIX) && !defined(__native_client__)
+  bool has_ipv4 = false;
+  struct ifaddrs* ifa;
+  if (getifaddrs(&ifa) < 0) {
+    return false;
+  }
+  for (struct ifaddrs* cur = ifa; cur != nullptr; cur = cur->ifa_next) {
+    if (cur->ifa_addr->sa_family == AF_INET) {
+      has_ipv4 = true;
+      break;

[pthatcher1, 2017/05/15 21:50:31]

Why not just "freeifaddrs(ifa); return true;"?

+    }
+  }
+  freeifaddrs(ifa);
+  return has_ipv4;
+#else
+  return true;
+#endif
+}
+
 bool HasIPv6Enabled() {
 #if defined(WEBRTC_WIN)
   if (IsWindowsVistaOrLater()) {
     return true;
   }
   if (!IsWindowsXpOrLater()) {
     return false;
   }
   DWORD protbuff_size = 4096;
   std::unique_ptr<char[]> protocols;
@@ skipping 36 matching lines @@
       break;
     }
   }
   freeifaddrs(ifa);
   return has_ipv6;
 #else
   return true;
 #endif
 }
 }  // namespace rtc