Fix GetNetworkList() for POSIX to cope with address-less interfaces.

net/base/net_util_posix.cc

Index: net/base/net_util_posix.cc
diff --git a/net/base/net_util_posix.cc b/net/base/net_util_posix.cc
index 0412792ebb2e38efcf67e3ad76ad53463508eb3b..8b6bd64bcaa3308ba6328c6c0c35770dfe1589d3 100644
--- a/net/base/net_util_posix.cc
+++ b/net/base/net_util_posix.cc
@@ -76,6 +76,8 @@ bool GetNetworkList(NetworkInterfaceList* networks) {
 
   for (ifaddrs *ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
     int family = ifa->ifa_addr->sa_family;
+    if (!ifa->ifa_addr)
+      continue;

[wtc, 2011/08/10 19:29:02]

Did you test this patch?  On line 78 you have already
dereferenced ifa->ifa_addr.  The null pointer test needs to
be done the first thing in the for loop's body.

Please also add a comment to explain why ifa->ifa_addr can
be NULL (it is a network interface with no IP address).

Just curious: in that case, does the ifa->ifa_name field
still contain the correct network interface name?

[wtc, 2011/08/10 19:32:22]

I checked the other two getifaddrs calls in net/base/net_util.cc.
They already have this null pointer test.

     if (family == AF_INET || family == AF_INET6) {
       IPEndPoint address;
       std::string name = ifa->ifa_name;