When scanning interfaces with WMI, ignore those without DNS

configuration.  [#834]

diff --git a/dns/win32util.py b/dns/win32util.py
index 14fc17e0db2b2e1eb9a18bc0244c2ca841f7da5b..deebc818b8b04b8aa860c1f33a7d315f7e0dc0ce 100644 (file)
--- a/dns/win32util.py
+++ b/dns/win32util.py
@@ -45,13 +45,14 @@ if sys.platform == "win32":
                 try:
                     system = wmi.WMI()
                     for interface in system.Win32_NetworkAdapterConfiguration():
-                        if interface.IPEnabled:
+                        if interface.IPEnabled and interface.DNSDomain:
                             self.info.domain = _config_domain(interface.DNSDomain)
                             self.info.nameservers = list(interface.DNSServerSearchOrder)
-                            self.info.search = [
-                                dns.name.from_text(x)
-                                for x in interface.DNSDomainSuffixSearchOrder
-                            ]
+                            if interface.DNSDomainSuffixSearchOrder:
+                                self.info.search = [
+                                    dns.name.from_text(x)
+                                    for x in interface.DNSDomainSuffixSearchOrder
+                                ]
                             break
                 finally:
                     pythoncom.CoUninitialize()