Traceback from futurize on single-line __future__ imports

[Valloric]

For the following test1.py file, futurize works just fine:

from __future__ import absolute_import
from __future__ import unicode_literals
from __future__ import print_function
from __future__ import division
from future import standard_library
standard_library.install_aliases()
from builtins import *

def foo():
  print('foo')

But for the same file with slightly differently organized imports:

from __future__ import ( absolute_import, unicode_literals, print_function,
                         division )
from future import standard_library
standard_library.install_aliases()
from builtins import *

def foo():
  print('foo')

futurize fails with the following traceback:

Traceback (most recent call last):
  File "/usr/local/bin/futurize", line 9, in <module>
    load_entry_point('future', 'console_scripts', 'futurize')()
  File "/home/valloric/repos/python-future/src/libfuturize/main.py", line 293, in main
    options.processes)
  File "/usr/lib/python2.7/lib2to3/refactor.py", line 706, in refactor
    items, write, doctests_only)
  File "/usr/lib/python2.7/lib2to3/refactor.py", line 301, in refactor
    self.refactor_file(dir_or_file, write, doctests_only)
  File "/usr/lib/python2.7/lib2to3/refactor.py", line 747, in refactor_file
    *args, **kwargs)
  File "/usr/lib/python2.7/lib2to3/refactor.py", line 354, in refactor_file
    tree = self.refactor_string(input, filename)
  File "/usr/lib/python2.7/lib2to3/refactor.py", line 386, in refactor_string
    self.refactor_tree(tree, name)
  File "/usr/lib/python2.7/lib2to3/refactor.py", line 460, in refactor_tree
    new = fixer.transform(node, results)
  File "/home/valloric/repos/python-future/src/libpasteurize/fixes/fix_add_all__future__imports.py", line 21, in transform
    future_import(u"unicode_literals", node)
  File "/home/valloric/repos/python-future/src/libfuturize/fixer_util.py", line 249, in future_import
    names = check_future_import(node)
  File "/home/valloric/repos/python-future/src/libfuturize/fixer_util.py", line 468, in check_future_import
    assert False, "strange import: %s" % savenode
AssertionError: strange import: from __future__ import ( absolute_import, unicode_literals, print_function,
                         division )

Futurize call: futurize -v -w -u -a -2 -n test.py

[QuLogic]

Dupe of #113.