[PATCH STABLE] graft: use opts.get() consistently

[Gábor Stefanik]

# HG changeset patch
# User Gábor Stefanik <gabor.stefanik at nng.com>
# Date 1469458842 -7200
#      Mon Jul 25 17:00:42 2016 +0200
# Branch stable
# Node ID 8c2595fa5ecd6d1274b742ab818c7bb3e82c50ed
# Parent  9c2cc107547fd701a7604349632f2f590366f17c
graft: use opts.get() consistently

Make life easier for extension writers.

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -4089,12 +4089,12 @@
         return _dograft(ui, repo, *revs, **opts)
 
 def _dograft(ui, repo, *revs, **opts):
-    if revs and opts['rev']:
+    if revs and opts.get('rev'):
         ui.warn(_('warning: inconsistent use of --rev might give unexpected '
                   'revision ordering!\n'))
 
     revs = list(revs)
-    revs.extend(opts['rev'])
+    revs.extend(opts.get('rev'))
 
     if not opts.get('user') and opts.get('currentuser'):
         opts['user'] = ui.username()
@@ -4104,7 +4104,7 @@
     editor = cmdutil.getcommiteditor(editform='graft', **opts)
 
     cont = False
-    if opts['continue']:
+    if opts.get('continue'):
         cont = True
         if revs:
             raise error.Abort(_("can't specify --continue and revisions"))