diff --git a/libs/requests/adapters.py b/libs/requests/adapters.py
index edc1af6..cdc5744 100644
--- a/libs/requests/adapters.py
+++ b/libs/requests/adapters.py
@@ -35,6 +35,7 @@ from .auth import _basic_auth_str
 DEFAULT_POOLBLOCK = False
 DEFAULT_POOLSIZE = 10
 DEFAULT_RETRIES = 0
+DEFAULT_POOL_TIMEOUT = None
 
 
 class BaseAdapter(object):
@@ -326,8 +327,8 @@ class HTTPAdapter(BaseAdapter):
         :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
         :param stream: (optional) Whether to stream the request content.
         :param timeout: (optional) How long to wait for the server to send
-            data before giving up, as a float, or a (`connect timeout, read
-            timeout <user/advanced.html#timeouts>`_) tuple.
+            data before giving up, as a float, or a :ref:`(connect timeout,
+            read timeout) <timeouts>` tuple.
         :type timeout: float or tuple
         :param verify: (optional) Whether to verify SSL certificates.
         :param cert: (optional) Any user-provided SSL certificate to be trusted.
@@ -375,7 +376,7 @@ class HTTPAdapter(BaseAdapter):
                 if hasattr(conn, 'proxy_pool'):
                     conn = conn.proxy_pool
 
-                low_conn = conn._get_conn(timeout=timeout)
+                low_conn = conn._get_conn(timeout=DEFAULT_POOL_TIMEOUT)
 
                 try:
                     low_conn.putrequest(request.method,
diff --git a/libs/requests/api.py b/libs/requests/api.py
index d40fa38..72a777b 100644
--- a/libs/requests/api.py
+++ b/libs/requests/api.py
@@ -27,8 +27,8 @@ def request(method, url, **kwargs):
     :param files: (optional) Dictionary of ``'name': file-like-objects`` (or ``{'name': ('filename', fileobj)}``) for multipart encoding upload.
     :param auth: (optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.
     :param timeout: (optional) How long to wait for the server to send data
-        before giving up, as a float, or a (`connect timeout, read timeout
-        <user/advanced.html#timeouts>`_) tuple.
+        before giving up, as a float, or a :ref:`(connect timeout, read
+        timeout) <timeouts>` tuple.
     :type timeout: float or tuple
     :param allow_redirects: (optional) Boolean. Set to True if POST/PUT/DELETE redirect following is allowed.
     :type allow_redirects: bool
diff --git a/libs/requests/sessions.py b/libs/requests/sessions.py
index 820919e..7c75460 100644
--- a/libs/requests/sessions.py
+++ b/libs/requests/sessions.py
@@ -63,12 +63,10 @@ def merge_setting(request_setting, session_setting, dict_class=OrderedDict):
     merged_setting.update(to_key_val_list(request_setting))
 
     # Remove keys that are set to None.
-    for (k, v) in request_setting.items():
+    for (k, v) in merged_setting.items():
         if v is None:
             del merged_setting[k]
 
-    merged_setting = dict((k, v) for (k, v) in merged_setting.items() if v is not None)
-
     return merged_setting
 
 
@@ -275,6 +273,12 @@ class Session(SessionRedirectMixin):
       >>> s = requests.Session()
       >>> s.get('http://httpbin.org/get')
       200
+
+    Or as a context manager::
+
+      >>> with requests.Session() as s:
+      >>>     s.get('http://httpbin.org/get')
+      200
     """
 
     __attrs__ = [
@@ -418,8 +422,8 @@ class Session(SessionRedirectMixin):
         :param auth: (optional) Auth tuple or callable to enable
             Basic/Digest/Custom HTTP Auth.
         :param timeout: (optional) How long to wait for the server to send
-            data before giving up, as a float, or a (`connect timeout, read
-            timeout <user/advanced.html#timeouts>`_) tuple.
+            data before giving up, as a float, or a :ref:`(connect timeout,
+            read timeout) <timeouts>` tuple.
         :type timeout: float or tuple
         :param allow_redirects: (optional) Set to True by default.
         :type allow_redirects: bool