None for parameter value should cause that param to be ignored

Fixes elastic#375

Author: honzakral

Changelog.rst

@@ -9,6 +9,8 @@ Changelog
 Version compatible with elasticsearch 5.0
 
  * added ``headers`` arg to connections to support custom http headers
+ * passing in a keyword parameter with ``None`` as value will cause that param
+ to be ignored 
 
 2.3.0 (2016-02-29)
 ------------------

elasticsearch/client/utils.py

@@ -33,7 +33,7 @@ def _escape(value):
  except UnicodeDecodeError:
  # Python 2 and str, no need to re-encode
  pass
- 
+
  return str(value)
 
 def _make_path(*parts):
@@ -60,7 +60,9 @@ def _wrapped(*args, **kwargs):
  params = kwargs.pop('params', {})
  for p in es_query_params + GLOBAL_PARAMS:
  if p in kwargs:
- params[p] = _escape(kwargs.pop(p))
+ v = kwargs.pop(p)
+ if v is not None:
+ params[p] = _escape(v)
 
  # don't treat ignore and request_timeout as other params to avoid escaping
  for p in ('ignore', 'request_timeout'):