ws2_32: Avoid a crash in WS_getaddrinfo when the specified service doesn't exist.

dlls/ws2_32/socket.c

@@ -6787,7 +6787,7 @@ int WINAPI WS_getaddrinfo(LPCSTR nodename, LPCSTR servname, const struct WS_addr
     result = getaddrinfo(node, servname, punixhints, &unixaires);
 
     if (result && (!hints || !(hints->ai_flags & WS_AI_NUMERICHOST))
-            && (!strcmp(fqdn, node) || (!strncmp(fqdn, node, hostname_len) && !node[hostname_len])))
+            && node && (!strcmp(fqdn, node) || (!strncmp(fqdn, node, hostname_len) && !node[hostname_len])))
     {
         /* If it didn't work it means the host name IP is not in /etc/hosts, try again
         * by sending a NULL host and avoid sending a NULL servname too because that

dlls/ws2_32/tests/sock.c

@@ -7778,6 +7778,10 @@ static void test_getaddrinfo(void)
                 ok(0, "test %d: getaddrinfo failed with %d (err %d)\n", i, ret, err);
         }
     }
+
+    memset(&hint, 0, sizeof(hint));
+    ret = pgetaddrinfo(NULL, "nonexistentservice", &hint, &result);
+    ok(ret == WSATYPE_NOT_FOUND, "got %d\n", ret);
 }
 
 static void test_ConnectEx(void)