`IndexError: list index out of range` on empty document

[SamVerschueren]

This is the error I get when I open a document with no content.

Python Server: Exception in thread Thread-9:
Traceback (most recent call last):
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 810, in__bootstrap_inner
    self.run()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 1082, in run
    self.function(*self.args, **self.kwargs)
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pyls/python_ls.py", line 100, in lint
    self.workspace.publish_diagnostics(doc_uri, flatten(self._hook('pyls_lint', doc_uri)))
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pyls/python_ls.py", line 28, in _hook
    return self._hook_caller(hook_name)(config=self.config, workspace=self.workspace, document=doc, **kwargs)
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/__init__.py", line 617, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/__init__.py", line 222, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/__init__.py", line 182, in __call__
    return outcome.get_result()
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/callers.py", line 77, in get_result
    _reraise(*ex)  # noqa
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/callers.py", line 48, in from_call
    result = func()
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/__init__.py", line 180, in <lambda>
    outcome = _Result.from_call(lambda: self.oldcall(hook, hook_impls, kwargs))
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/__init__.py", line 216, in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/callers.py", line 201, in _multicall
    return outcome.get_result()
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/callers.py", line 77, in get_result
    _reraise(*ex)  # noqa
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pluggy/callers.py", line 180, in _multicall
    res = hook_impl.function(*args)
  File "/Users/sam/Library/Python/2.7/lib/python/site-packages/pyls/plugins/pydocstyle_lint.py", line 37, in pyls_lint
    line = document.lines[lineno]
IndexError: list index out of range

It happens here.