Added debug parameter. More sanity checks. Return empty result set if no

actual results were returned.

get_updates.py

@@ -23,6 +23,7 @@ optp.add_option("--code", action="append", dest="unlock_codes", metavar="UNLOCK_
 optp.add_option("--devicexml", dest="devicexml", metavar="FILE", help="Use specified GarminDevice.xml (also implies -E)")
 optp.add_option("--json", action="store_true", dest="json", default=False, help="Output JSON")
 optp.add_option("--list-devices", action="store_true", dest="list_devices", default=False, help="Show a list of SKUs and product names")
+optp.add_option("--debug", action="store_true", dest="debug", default=False, help="Dump raw server requests and replies to files")
 
 optp.usage = """
   %prog [options] SKU1 [SKU2..SKUn]
@@ -50,6 +51,9 @@ elif len(device_skus) < 1 and not opts.devicexml:
 
 us = updateserver.UpdateServer()
 
+if opts.debug:
+    us.debug = True
+
 if opts.devicexml:
     # Filename given, load GarminDevice.xml from there; also disable WebUpdater
     print("Using GarminDevice.xml from {}.".format(opts.devicexml))