The getifaddrs() version of Curl_if2ip() crashed when used on a Linux

system with a TEQL load-balancing device configured, which doesn't
have an address.  Thanks to Adam Sampson for spotting this (bug #2234923).

CHANGES

@@ -6,6 +6,11 @@
 
                                   Changelog
 
+Daniel Fandrich (7 Nov 2008)
+- The getifaddrs() version of Curl_if2ip() crashed when used on a Linux
+  system with a TEQL load-balancing device configured, which doesn't
+  have an address.  Thanks to Adam Sampson for spotting this (bug #2234923).
+
 Yang Tse (6 Nov 2008)
 - Merged existing IPv4 and IPv6 Curl_ip2addr functions into a single one
   which now also takes a protocol address family argument.

RELEASE-NOTES

@@ -14,6 +14,7 @@ This release includes the following changes:
 This release includes the following bugfixes:
 
  o build failure when using MSVC 6 makefile
+ o crash when using --interface name on Linux systems with a TEQL device
 
 This release includes the following known bugs:
 
@@ -26,6 +27,6 @@ Other curl-related news:
 This release would not have looked like this without help, code, reports and
 advice from friends like these:
 
- John Wilkinson
+ John Wilkinson, Adam Sampson
 
         Thanks! (and sorry if I forgot to mention someone)

lib/if2ip.c

@@ -78,7 +78,8 @@ char *Curl_if2ip(int af, const char *interface, char *buf, int buf_size)
 
   if (getifaddrs(&head) >= 0) {
     for (iface=head; iface != NULL; iface=iface->ifa_next) {
-      if ((iface->ifa_addr->sa_family == af) &&
+      if ((iface->ifa_addr != NULL) &&
+          (iface->ifa_addr->sa_family == af) &&
           curl_strequal(iface->ifa_name, interface)) {
         void *addr;
         char scope[12]="";