[py3] Let InstanceCommand.run_arg() always return an int
The caller of this method (which is method "run_args") does `max(status,
self.run_arg(appid))` and run_arg might return None if the underlying
<cmdname>_instance method returns None. On python3 max(1, None) breaks
with "TypeError: unorderable types: int() > NoneType()". So we enforce
run_arg() method to return an integer even if the underlying method
returns None.
This fixes call of "cubicweb-ctl i18ninstance" with Python3.
"""This module compare the Schema on the file system to the one in the database"""
from cStringIO import StringIO
from cubicweb.web.schemaviewer import SchemaViewer
from logilab.common.ureports import TextWriter
import difflib
viewer = SchemaViewer()
layout_db = viewer.visit_schema(schema, display_relations=True)
layout_fs = viewer.visit_schema(fsschema, display_relations=True)
writer = TextWriter()
stream_db = StringIO()
stream_fs = StringIO()
writer.format(layout_db, stream=stream_db)
writer.format(layout_fs, stream=stream_fs)
stream_db.seek(0)
stream_fs.seek(0)
db = stream_db.getvalue().splitlines()
fs = stream_fs.getvalue().splitlines()
open('db_schema.txt', 'w').write(stream_db.getvalue())
open('fs_schema.txt', 'w').write(stream_fs.getvalue())
#for diff in difflib.ndiff(fs, db):
# print diff