Fix the bug of "openstack console log show"

The behaviors are inconsistent while different
negative line numbers specified.

Change-Id: I2573f3e789f5603c896758971830ffc0b94c5e2b
Closes-Bug: #1512263

1 files changed, 2 insertions, 0 deletions

diff --git a/openstackclient/compute/v2/console.py b/openstackclient/compute/v2/console.py
index bb0747b1..aafa5d44 100644
--- a/openstackclient/compute/v2/console.py
+++ b/openstackclient/compute/v2/console.py
@@ -22,6 +22,7 @@ import sys
 from cliff import command
 from cliff import show
 
+from openstackclient.common import parseractions
 from openstackclient.common import utils
 
 
@@ -42,6 +43,7 @@ class ShowConsoleLog(command.Command):
             metavar='<num-lines>',
             type=int,
             default=None,
+            action=parseractions.NonNegativeAction,
             help='Number of lines to display from the end of the log '
                  '(default=all)',
         )