configd, idna encode, orginating from #3107 and other commits from th…

…e same contributor.

Fix for #3107, although I'm doubting if we should keep supporting idna, since fixing these issues often cost us quite some time and demand for the feature doesn't appear to be very high.

src/opnsense/service/modules/template.py

@@ -67,8 +67,13 @@ def __init__(self, target_root_directory="/"):
     def _encode_idna(x):
         """ encode string to idna, preserve leading dots
         """
-        tmp = b''.join([b''.join([b'.' for x in range(len(x) - len(x.lstrip('.')))]), x.lstrip('.').encode('idna')])
-        return tmp.decode()
+        try:
+            tmp = b''.join([b''.join([b'.' for x in range(len(x) - len(x.lstrip('.')))]), x.lstrip('.').encode('idna')])
+            return tmp.decode()
+        except UnicodeError:
+            # return source when unable to decode
+            syslog.syslog(syslog.LOG_NOTICE, "encode idna: unable to decode %s, return source" % x)
+            return x
 
     def list_module(self, module_name):
         """ list single module content