cli: Break out function to disable libvirt error printing

We need it early in the test suite

tests/utils.py

@@ -71,6 +71,7 @@ def openconn(uri):
     generally every test uses a fresh virConnect, or undoes the
     persistent changes it makes.
     """
+    virtinst.util.register_libvirt_error_handler()
     conn = virtinst.cli.getConnection(uri)
 
     if uri not in _conn_cache:

virtinst/cli.py

@@ -200,12 +200,7 @@ def setupLogging(appname, debug_stdout, do_quiet, cli_app=True):
     if streamHandler:
         rootLogger.addHandler(streamHandler)
 
-    # Register libvirt handler
+    util.register_libvirt_error_handler()
-    def libvirt_callback(ignore, err):
-        if err[3] != libvirt.VIR_ERR_ERROR:
-            # Don't log libvirt errors: global error handler will do that
-            logging.warn("Non-error from libvirt: '%s'", err[2])
-    libvirt.registerErrorHandler(f=libvirt_callback, ctx=None)
 
     # Log uncaught exceptions
     def exception_log(typ, val, tb):

virtinst/util.py

@@ -517,3 +517,13 @@ def convert_units(value, old_unit, new_unit):
     power = get_power(new_unit)
 
     return in_bytes / pow(factor, power)
+
+
+def register_libvirt_error_handler():
+    """
+    Ignore libvirt error reporting, we just use exceptions
+    """
+    def libvirt_callback(userdata, err):
+        ignore = userdata
+        ignore = err
+    libvirt.registerErrorHandler(f=libvirt_callback, ctx=None)