diff --git a/.travis.yml b/.travis.yml
index ed1aa72..ca91b60 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,12 +10,14 @@
 
 env:
   global:
-    - pip_install_common='pip>=9.0 setuptools>=43.0 wheel>=0.30'
+    - pip_install_common='pip>=9.0 setuptools>=36.2 wheel>=0.30'
 python:
   - 2.7
   - 3.5
   - 3.6
   - 3.7
+matrix:
+  fast_finish: true
 install: pip install $pip_install_common 'codecov>=2.0.15' -r requirements-test.txt
 script: script/test -sv && codecov
 
@@ -23,7 +25,6 @@
   - test
   - release
 jobs:
-  fast_finish: true
   include:
     - stage: test
       python: pypy
@@ -68,7 +69,7 @@
       deploy:
         provider: pypi
         server: https://test.pypi.org/legacy/
-        username: httplib2.release.test
+        user: httplib2.release.test
         password:
           secure: "XN3oxobC+26UPiS+F1MvL4c6XtytejZ13SkLXCHfgVDPSASzKqF81CnR4EhsnbfZLvSgGHgSlfY5Jve5HF2VR9GzpJMc6wzcfkkeBg6PeRHuMppIqmuoq7BTw81SZL9X62/mju/vxXs2cHpVkwNTSE7W1JH1bVXPj86oAR9xXo9waRuXcyPGNuSqmOd1NPOMbFmeuz+HeArk2Fz7wwo6H5BJuXjOrEOHWD1rzeRchH901PBUrftm54Id2TIVMARW8jm1saQY2FtPWaBv2v/DJC1fKWMJpcNQ3mmcvrrTFC1IJ00dk9XJfqx5hnsRaergc0UvzHoOGEQKSMdg0PUAkvNohAoCf+3GddPkvk8MaZ+aQlijoK6wp93A5dfTxBVZqdhmEdheolbYiJPunzS60bWvaEv6/D15/xyMiwGamUmF1Tx7UIvvm/zj6tAOBWbNEgLRyvQ0qx2RE95GLtp+RXK4pT+Kig1+cof5hrWODuEl1SSLMBySaNLWO73IN9esZu0X1JS7svnROLRJCAvRjppJYswwCPziP+B8XQDeMrhIDMHNzdbtxOPpBAXpYUE764FkzaUTMsK83Q+ugE3Dx8xtrAzT4M0fdiFv+3QEhSUtfvWsLH9zS9wXC5Px9kPKU3FO8mdUyf7A0bIasvJLNcApDJigKjBukToOIsZVFok="
         distributions: "sdist bdist_wheel"
@@ -83,7 +84,7 @@
       script: script/release -auto
       deploy:
         provider: pypi
-        username: httplib2.release
+        user: httplib2.release
         password:
           secure: "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"
         distributions: "sdist bdist_wheel"
diff --git a/Android.bp b/Android.bp
index c77abc6..05d69ac 100644
--- a/Android.bp
+++ b/Android.bp
@@ -12,42 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package {
-    default_applicable_licenses: ["external_python_httplib2_license"],
-}
-
-// Added automatically by a large-scale-change that took the approach of
-// 'apply every license found to every target'. While this makes sure we respect
-// every license restriction, it may not be entirely correct.
-//
-// e.g. GPL in an MIT project might only apply to the contrib/ directory.
-//
-// Please consider splitting the single license below into multiple licenses,
-// taking care not to lose any license_kind information, and overriding the
-// default license using the 'licenses: [...]' property on targets as needed.
-//
-// For unused files, consider creating a 'fileGroup' with "//visibility:private"
-// to attach the license to, and including a comment whether the files may be
-// used in the current project.
-// See: http://go/android-license-faq
-license {
-    name: "external_python_httplib2_license",
-    visibility: [":__subpackages__"],
-    license_kinds: [
-        "SPDX-license-identifier-Apache-2.0",
-        "SPDX-license-identifier-BSD",
-        "SPDX-license-identifier-GPL",
-        "SPDX-license-identifier-GPL-2.0",
-        "SPDX-license-identifier-LGPL-2.1",
-        "SPDX-license-identifier-MIT",
-        "SPDX-license-identifier-MPL",
-        "SPDX-license-identifier-MPL-1.1",
-    ],
-    license_text: [
-        "LICENSE",
-    ],
-}
-
 filegroup {
     // "cacerts.txt" are identical save for the fact that py3 cacerts.txt has
     // a newline at the end while py2 cacerts.txt doesn't.
diff --git a/CHANGELOG b/CHANGELOG
index 2db1cc0..07fb949 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,52 +1,3 @@
-0.18.1
-
-  explicit build-backend workaround for pip build isolation bug
-  "AttributeError: 'module' object has no attribute '__legacy__'" on pip install
-  https://github.com/httplib2/httplib2/issues/169
-
-0.18.0
-
-  IMPORTANT security vulnerability CWE-93 CRLF injection
-  Force %xx quote of space, CR, LF characters in uri.
-  Special thanks to Recar https://github.com/Ciyfly for discrete notification.
-  https://cwe.mitre.org/data/definitions/93.html
-
-0.17.4
-
-  Ship test suite in source dist
-  https://github.com/httplib2/httplib2/pull/168
-
-0.17.3
-
-  IronPython2.7: relative import iri2uri fixes ImportError
-  https://github.com/httplib2/httplib2/pull/163
-
-0.17.2
-
-  python3 + debug + IPv6 disabled: https raised
-  "IndexError: Replacement index 1 out of range for positional args tuple"
-  https://github.com/httplib2/httplib2/issues/161
-
-0.17.1
-
-  python3: no_proxy was not checked with https
-  https://github.com/httplib2/httplib2/issues/160
-
-0.17.0
-
-  feature: Http().redirect_codes set, works after follow(_all)_redirects check
-  This allows one line workaround for old gcloud library that uses 308
-  response without redirect semantics.
-  https://github.com/httplib2/httplib2/issues/156
-
-0.16.0
-
-  IMPORTANT cache invalidation change, fix 307 keep method, add 308 Redirects
-  https://github.com/httplib2/httplib2/issues/151
-
-  proxy: username/password as str compatible with pysocks
-  https://github.com/httplib2/httplib2/issues/154
-
 0.15.0
 
   python2: regression in connect() error handling
diff --git a/MANIFEST.in b/MANIFEST.in
index 412def6..12c4cc7 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,11 +1,4 @@
 recursive-include python2 *.py *.txt
 recursive-include python3 *.py *.txt
-graft test
-graft tests
-include *.md
-include CHANGELOG
-include LICENSE
 include python2/httplib2/test/*.txt
 include requirements*.txt
-global-exclude __pycache__
-global-exclude *.py[cod]
diff --git a/METADATA b/METADATA
index bcdbd44..8b3c1c6 100644
--- a/METADATA
+++ b/METADATA
@@ -9,14 +9,10 @@
     type: GIT
     value: "https://github.com/httplib2/httplib2.git"
   }
-  version: "v0.18.1"
-  # would be NOTICE save for:
-  #   test/other_cacerts.txt
-  #   doc/html/_static/jquery.js
-  license_type: RESTRICTED
+  version: "v0.15.0"
   last_upgrade_date {
-    year: 2020
-    month: 5
-    day: 20
+    year: 2019
+    month: 12
+    day: 23
   }
 }
diff --git a/NOTICE b/NOTICE
new file mode 120000
index 0000000..7a694c9
--- /dev/null
+++ b/NOTICE
@@ -0,0 +1 @@
+LICENSE
\ No newline at end of file
diff --git a/OWNERS b/OWNERS
index 110ac37..e6fbf8d 100644
--- a/OWNERS
+++ b/OWNERS
@@ -2,3 +2,4 @@
 # or people with more than 10 commits last year.
 # Please update this list if you find better owner candidates.
 herbertxue@google.com
+yim@google.com
diff --git a/SECURITY.md b/SECURITY.md
deleted file mode 100644
index 5eb3903..0000000
--- a/SECURITY.md
+++ /dev/null
@@ -1,19 +0,0 @@
-# Security Policy
-
-## Supported Versions
-
-master branch and latest release get priority support. You should expect all known problems fixed in master.
-
-All other released versions receive security updates per request.
-If you use some old version and can not upgrade for any or no reason, ask for security update release, most likely you will get it.
-
-## Reporting a Vulnerability
-
-Contact current maintainers. At 2020-05: temotor@gmail.com or https://t.me/temotor
-If that doesn't work, open Github issue just asking for private communication channel.
-
-This is volunteer maintained project, all issues are processed on best effort basis, no deadlines promised. Of course, security vulnerabilities get priority over regular issues.
-
-You can expect fame in history or maybe you prefer anonymity - say what you prefer.
-
-Thank you for responsible handling of security problems. Your attention and effort are appreciated.
diff --git a/TEST_MAPPING b/TEST_MAPPING
new file mode 100644
index 0000000..61a80b2
--- /dev/null
+++ b/TEST_MAPPING
@@ -0,0 +1,8 @@
+{
+  "presubmit" : [
+    {
+      "name" : "acloud_test",
+      "host" : true
+    }
+  ]
+}
diff --git a/pyproject.toml b/pyproject.toml
deleted file mode 100644
index 5f7cbbd..0000000
--- a/pyproject.toml
+++ /dev/null
@@ -1,9 +0,0 @@
-[build-system]
-requires = ["setuptools >= 40.8.0", "wheel"]
-build-backend = "setuptools.build_meta"
-
-[tool.black]
-line-length = 121
-
-[tool.check-manifest]
-ignore = [".travis.yml", "script/*", "*.tex"]
diff --git a/python2/httplib2/__init__.py b/python2/httplib2/__init__.py
index f35ba48..c8302eb 100644
--- a/python2/httplib2/__init__.py
+++ b/python2/httplib2/__init__.py
@@ -19,7 +19,7 @@
     "Alex Yu",
 ]
 __license__ = "MIT"
-__version__ = "0.18.1"
+__version__ = '0.15.0'
 
 import base64
 import calendar
@@ -129,7 +129,7 @@
     _ssl_wrap_socket = _ssl_wrap_socket_unsupported
 
 if sys.version_info >= (2, 3):
-    from .iri2uri import iri2uri
+    from iri2uri import iri2uri
 else:
 
     def iri2uri(uri):
@@ -291,12 +291,6 @@
     "upgrade",
 ]
 
-# https://tools.ietf.org/html/rfc7231#section-8.1.3
-SAFE_METHODS = ("GET", "HEAD")  # TODO add "OPTIONS", "TRACE"
-
-# To change, assign to `Http().redirect_codes`
-REDIRECT_CODES = frozenset((300, 301, 302, 303, 307, 308))
-
 
 def _get_end2end_headers(response):
     hopbyhop = list(HOP_BY_HOP)
@@ -1181,9 +1175,9 @@
 
             host = self.host
             port = self.port
-
+        
         socket_err = None
-
+        
         for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
             af, socktype, proto, canonname, sa = res
             try:
@@ -1359,9 +1353,9 @@
 
             host = self.host
             port = self.port
-
+            
         socket_err = None
-
+        
         address_info = socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM)
         for family, socktype, proto, canonname, sockaddr in address_info:
             try:
@@ -1667,14 +1661,10 @@
         # If set to False then no redirects are followed, even safe ones.
         self.follow_redirects = True
 
-        self.redirect_codes = REDIRECT_CODES
-
         # Which HTTP methods do we apply optimistic concurrency to, i.e.
         # which methods get an "if-match:" etag header added to them.
         self.optimistic_concurrency_methods = ["PUT", "PATCH"]
 
-        self.safe_methods = list(SAFE_METHODS)
-
         # If 'follow_redirects' is True, and this is set to True then
         # all redirecs are followed, including unsafe ones.
         self.follow_all_redirects = False
@@ -1868,10 +1858,10 @@
 
         if (
             self.follow_all_redirects
-            or method in self.safe_methods
-            or response.status in (303, 308)
+            or (method in ["GET", "HEAD"])
+            or response.status == 303
         ):
-            if self.follow_redirects and response.status in self.redirect_codes:
+            if self.follow_redirects and response.status in [300, 301, 302, 303, 307]:
                 # Pick out the location header and basically start from the beginning
                 # remembering first to strip the ETag header and decrement our 'depth'
                 if redirections:
@@ -1891,7 +1881,7 @@
                             response["location"] = urlparse.urljoin(
                                 absolute_uri, location
                             )
-                    if response.status == 308 or (response.status == 301 and method in self.safe_methods):
+                    if response.status == 301 and method in ["GET", "HEAD"]:
                         response["-x-permanent-redirect-url"] = response["location"]
                         if "content-location" not in response:
                             response["content-location"] = absolute_uri
@@ -1928,7 +1918,7 @@
                         response,
                         content,
                     )
-            elif response.status in [200, 203] and method in self.safe_methods:
+            elif response.status in [200, 203] and method in ["GET", "HEAD"]:
                 # Don't cache 206's since we aren't going to handle byte range requests
                 if "content-location" not in response:
                     response["content-location"] = absolute_uri
@@ -1985,9 +1975,6 @@
                 headers["user-agent"] = "Python-httplib2/%s (gzip)" % __version__
 
             uri = iri2uri(uri)
-            # Prevent CWE-75 space injection to manipulate request via part of uri.
-            # Prevent CWE-93 CRLF injection to modify headers via part of uri.
-            uri = uri.replace(" ", "%20").replace("\r", "%0D").replace("\n", "%0A")
 
             (scheme, authority, request_uri, defrag_uri) = urlnorm(uri)
 
@@ -2031,7 +2018,6 @@
                 headers["accept-encoding"] = "gzip, deflate"
 
             info = email.Message.Message()
-            cachekey = None
             cached_value = None
             if self.cache:
                 cachekey = defrag_uri.encode("utf-8")
@@ -2052,6 +2038,8 @@
                         self.cache.delete(cachekey)
                         cachekey = None
                         cached_value = None
+            else:
+                cachekey = None
 
             if (
                 method in self.optimistic_concurrency_methods
@@ -2063,15 +2051,13 @@
                 # http://www.w3.org/1999/04/Editing/
                 headers["if-match"] = info["etag"]
 
-            # https://tools.ietf.org/html/rfc7234
-            # A cache MUST invalidate the effective Request URI as well as [...] Location and Content-Location
-            # when a non-error status code is received in response to an unsafe request method.
-            if self.cache and cachekey and method not in self.safe_methods:
+            if method not in ["GET", "HEAD"] and self.cache and cachekey:
+                # RFC 2616 Section 13.10
                 self.cache.delete(cachekey)
 
             # Check the vary header in the cache to see if this request
             # matches what varies in the cache.
-            if method in self.safe_methods and "vary" in info:
+            if method in ["GET", "HEAD"] and "vary" in info:
                 vary = info["vary"]
                 vary_headers = vary.lower().replace(" ", "").split(",")
                 for header in vary_headers:
@@ -2082,14 +2068,11 @@
                         break
 
             if (
-                self.cache
-                and cached_value
-                and (method in self.safe_methods or info["status"] == "308")
+                cached_value
+                and method in ["GET", "HEAD"]
+                and self.cache
                 and "range" not in headers
             ):
-                redirect_method = method
-                if info["status"] not in ("307", "308"):
-                    redirect_method = "GET"
                 if "-x-permanent-redirect-url" in info:
                     # Should cached permanent redirects be counted in our redirection count? For now, yes.
                     if redirections <= 0:
@@ -2100,7 +2083,7 @@
                         )
                     (response, new_content) = self.request(
                         info["-x-permanent-redirect-url"],
-                        method=redirect_method,
+                        method="GET",
                         headers=headers,
                         redirections=redirections - 1,
                     )
diff --git a/python2/httplib2/socks.py b/python2/httplib2/socks.py
index 71eb4eb..5cef776 100644
--- a/python2/httplib2/socks.py
+++ b/python2/httplib2/socks.py
@@ -238,15 +238,7 @@
         headers -     Additional or modified headers for the proxy connect
         request.
         """
-        self.__proxy = (
-            proxytype,
-            addr,
-            port,
-            rdns,
-            username.encode() if username else None,
-            password.encode() if password else None,
-            headers,
-        )
+        self.__proxy = (proxytype, addr, port, rdns, username, password, headers)
 
     def __negotiatesocks5(self, destaddr, destport):
         """__negotiatesocks5(self,destaddr,destport)
diff --git a/python3/httplib2/__init__.py b/python3/httplib2/__init__.py
index cf2db60..d8c3d34 100644
--- a/python3/httplib2/__init__.py
+++ b/python3/httplib2/__init__.py
@@ -15,7 +15,7 @@
     "Alex Yu",
 ]
 __license__ = "MIT"
-__version__ = "0.18.1"
+__version__ = '0.15.0'
 
 import base64
 import calendar
@@ -161,13 +161,6 @@
     "upgrade",
 ]
 
-# https://tools.ietf.org/html/rfc7231#section-8.1.3
-SAFE_METHODS = ("GET", "HEAD", "OPTIONS", "TRACE")
-
-# To change, assign to `Http().redirect_codes`
-REDIRECT_CODES = frozenset((300, 301, 302, 303, 307, 308))
-
-
 from httplib2 import certs
 CA_CERTS = certs.where()
 
@@ -322,7 +315,7 @@
 # Whether to use a strict mode to parse WWW-Authenticate headers
 # Might lead to bad results in case of ill-formed header value,
 # so disabled by default, falling back to relaxed parsing.
-# Set to true to turn on, useful for testing servers.
+# Set to true to turn on, usefull for testing servers.
 USE_WWW_AUTH_STRICT_PARSING = 0
 
 # In regex below:
@@ -1011,10 +1004,10 @@
           proxy_headers: Additional or modified headers for the proxy connect
           request.
         """
-        if isinstance(proxy_user, bytes):
-            proxy_user = proxy_user.decode()
-        if isinstance(proxy_pass, bytes):
-            proxy_pass = proxy_pass.decode()
+        if isinstance(proxy_user, str):
+            proxy_user = proxy_user.encode()
+        if isinstance(proxy_pass, str):
+            proxy_pass = proxy_pass.encode()
         self.proxy_type, self.proxy_host, self.proxy_port, self.proxy_rdns, self.proxy_user, self.proxy_pass, self.proxy_headers = (
             proxy_type,
             proxy_host,
@@ -1284,7 +1277,7 @@
 
     def connect(self):
         """Connect to a host on a given (SSL) port."""
-        if self.proxy_info and self.proxy_info.isgood() and self.proxy_info.applies_to(self.host):
+        if self.proxy_info and self.proxy_info.isgood():
             use_proxy = True
             proxy_type, proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass, proxy_headers = (
                 self.proxy_info.astuple()
@@ -1366,7 +1359,7 @@
             except socket.error as e:
                 socket_err = e
                 if self.debuglevel > 0:
-                    print("connect fail: ({0}, {1})".format(self.host, self.port))
+                    print("connect fail: ({0}, {1})".format((self.host, self.port)))
                     if use_proxy:
                         print(
                             "proxy: {0}".format(
@@ -1474,14 +1467,10 @@
         # If set to False then no redirects are followed, even safe ones.
         self.follow_redirects = True
 
-        self.redirect_codes = REDIRECT_CODES
-
         # Which HTTP methods do we apply optimistic concurrency to, i.e.
         # which methods get an "if-match:" etag header added to them.
         self.optimistic_concurrency_methods = ["PUT", "PATCH"]
 
-        self.safe_methods = list(SAFE_METHODS)
-
         # If 'follow_redirects' is True, and this is set to True then
         # all redirecs are followed, including unsafe ones.
         self.follow_all_redirects = False
@@ -1674,10 +1663,10 @@
 
         if (
             self.follow_all_redirects
-            or method in self.safe_methods
-            or response.status in (303, 308)
+            or (method in ["GET", "HEAD"])
+            or response.status == 303
         ):
-            if self.follow_redirects and response.status in self.redirect_codes:
+            if self.follow_redirects and response.status in [300, 301, 302, 303, 307]:
                 # Pick out the location header and basically start from the beginning
                 # remembering first to strip the ETag header and decrement our 'depth'
                 if redirections:
@@ -1697,7 +1686,7 @@
                             response["location"] = urllib.parse.urljoin(
                                 absolute_uri, location
                             )
-                    if response.status == 308 or (response.status == 301 and (method in self.safe_methods)):
+                    if response.status == 301 and method in ["GET", "HEAD"]:
                         response["-x-permanent-redirect-url"] = response["location"]
                         if "content-location" not in response:
                             response["content-location"] = absolute_uri
@@ -1734,7 +1723,7 @@
                         response,
                         content,
                     )
-            elif response.status in [200, 203] and method in self.safe_methods:
+            elif response.status in [200, 203] and method in ["GET", "HEAD"]:
                 # Don't cache 206's since we aren't going to handle byte range requests
                 if "content-location" not in response:
                     response["content-location"] = absolute_uri
@@ -1790,9 +1779,6 @@
                 headers["user-agent"] = "Python-httplib2/%s (gzip)" % __version__
 
             uri = iri2uri(uri)
-            # Prevent CWE-75 space injection to manipulate request via part of uri.
-            # Prevent CWE-93 CRLF injection to modify headers via part of uri.
-            uri = uri.replace(" ", "%20").replace("\r", "%0D").replace("\n", "%0A")
 
             (scheme, authority, request_uri, defrag_uri) = urlnorm(uri)
 
@@ -1836,7 +1822,6 @@
                 headers["accept-encoding"] = "gzip, deflate"
 
             info = email.message.Message()
-            cachekey = None
             cached_value = None
             if self.cache:
                 cachekey = defrag_uri
@@ -1854,6 +1839,8 @@
                         self.cache.delete(cachekey)
                         cachekey = None
                         cached_value = None
+            else:
+                cachekey = None
 
             if (
                 method in self.optimistic_concurrency_methods
@@ -1865,15 +1852,13 @@
                 # http://www.w3.org/1999/04/Editing/
                 headers["if-match"] = info["etag"]
 
-            # https://tools.ietf.org/html/rfc7234
-            # A cache MUST invalidate the effective Request URI as well as [...] Location and Content-Location
-            # when a non-error status code is received in response to an unsafe request method.
-            if self.cache and cachekey and method not in self.safe_methods:
+            if method not in ["GET", "HEAD"] and self.cache and cachekey:
+                # RFC 2616 Section 13.10
                 self.cache.delete(cachekey)
 
             # Check the vary header in the cache to see if this request
             # matches what varies in the cache.
-            if method in self.safe_methods and "vary" in info:
+            if method in ["GET", "HEAD"] and "vary" in info:
                 vary = info["vary"]
                 vary_headers = vary.lower().replace(" ", "").split(",")
                 for header in vary_headers:
@@ -1884,14 +1869,11 @@
                         break
 
             if (
-                self.cache
-                and cached_value
-                and (method in self.safe_methods or info["status"] == "308")
+                cached_value
+                and method in ["GET", "HEAD"]
+                and self.cache
                 and "range" not in headers
             ):
-                redirect_method = method
-                if info["status"] not in ("307", "308"):
-                    redirect_method = "GET"
                 if "-x-permanent-redirect-url" in info:
                     # Should cached permanent redirects be counted in our redirection count? For now, yes.
                     if redirections <= 0:
@@ -1902,7 +1884,7 @@
                         )
                     (response, new_content) = self.request(
                         info["-x-permanent-redirect-url"],
-                        method=redirect_method,
+                        method="GET",
                         headers=headers,
                         redirections=redirections - 1,
                     )
diff --git a/python3/httplib2/socks.py b/python3/httplib2/socks.py
index cc68e63..2926b4e 100644
--- a/python3/httplib2/socks.py
+++ b/python3/httplib2/socks.py
@@ -238,15 +238,7 @@
         headers -     Additional or modified headers for the proxy connect
         request.
         """
-        self.__proxy = (
-            proxytype,
-            addr,
-            port,
-            rdns,
-            username.encode() if username else None,
-            password.encode() if password else None,
-            headers,
-        )
+        self.__proxy = (proxytype, addr, port, rdns, username, password, headers)
 
     def __negotiatesocks5(self, destaddr, destport):
         """__negotiatesocks5(self,destaddr,destport)
diff --git a/script/compile-py3-openssl11.sh b/script/compile-py3-openssl11.sh
index 59f5022..3486043 100644
--- a/script/compile-py3-openssl11.sh
+++ b/script/compile-py3-openssl11.sh
@@ -3,7 +3,7 @@
 cache_dir=$HOME/.cache
 install_dir=$cache_dir/py3-openssl11
 python_version="3.7.3"
-openssl_version="1.1.1f"
+openssl_version="1.1.1c"
 cpucount=$(nproc --all)
 export PYTHONDONTWRITEBYTECODE=1
 
@@ -14,7 +14,7 @@
   mkdir -p /tmp/source
   cd /tmp/source
   # Compile OpenSSL
-  curl -fLOsS "https://www.openssl.org/source/openssl-$openssl_version.tar.gz"
+  wget --quiet https://www.openssl.org/source/openssl-$openssl_version.tar.gz
   echo "Extracting OpenSSL..."
   tar xf openssl-$openssl_version.tar.gz
   cd ./openssl-$openssl_version
@@ -29,7 +29,7 @@
   cd /tmp/source
   sudo apt install -qq --yes libffi-dev
   # Compile latest Python
-  curl -fLOsS "https://www.python.org/ftp/python/$python_version/Python-$python_version.tar.xz"
+  wget --quiet https://www.python.org/ftp/python/$python_version/Python-$python_version.tar.xz
   echo "Extracting Python..."
   tar xf Python-$python_version.tar.xz
   cd ./Python-$python_version
diff --git a/script/release b/script/release
index a2ff80d..0f98e3e 100755
--- a/script/release
+++ b/script/release
@@ -45,9 +45,9 @@
 		last_tag=$(git tag --sort=-version:refname |head -n1)
 		last_tag=${last_tag##v}
 		version_replace="${last_tag}.post$(date -u +%y%m%d%H%M)"
-		update_version "setup.py" "s/VERSION =.+/VERSION = \"$version_replace\"/"
-		update_version "python2/httplib2/__init__.py" "s/__version__ =.+/__version__ = \"$version_replace\"/"
-		update_version "python3/httplib2/__init__.py" "s/__version__ =.+/__version__ = \"$version_replace\"/"
+		update_version "setup.py" "s/VERSION =.+/VERSION = '$version_replace'/"
+		update_version "python2/httplib2/__init__.py" "s/__version__ =.+/__version__ = '$version_replace'/"
+		update_version "python3/httplib2/__init__.py" "s/__version__ =.+/__version__ = '$version_replace'/"
 		version_check "$version_replace"
 	fi
 }
@@ -90,11 +90,10 @@
 	local venv=./venv-release
 	if [[ ! -d "$venv" ]] ; then
 		virtualenv $venv
-		$venv/bin/pip install -U check-manifest pip 'setuptools>=43.0' wheel twine
+		$venv/bin/pip install -U pip setuptools wheel twine
 	fi
 	$venv/bin/python setup.py clean --all
 	$venv/bin/python setup.py sdist bdist_wheel
-	$venv/bin/check-manifest || echo "FIXME check-manifest" >&2
 
 	if confirm "Upload to PyPI? Use in special situation, normally CI (Travis) will upload to PyPI. [yN] " ; then
 		$venv/bin/twine upload dist/* || exit 1
@@ -133,9 +132,9 @@
 	fi
 	echo "Next version:    '$version_next'" >&2
 
-	update_version "python3/httplib2/__init__.py" "s/__version__ =.+/__version__ = \"$version_next\"/"
-	update_version "python2/httplib2/__init__.py" "s/__version__ =.+/__version__ = \"$version_next\"/"
-	update_version "setup.py" "s/VERSION =.+/VERSION = \"$version_next\"/"
+	update_version "python3/httplib2/__init__.py" "s/__version__ =.+/__version__ = '$version_next'/"
+	update_version "python2/httplib2/__init__.py" "s/__version__ =.+/__version__ = '$version_next'/"
+	update_version "setup.py" "s/VERSION =.+/VERSION = '$version_next'/"
 
 	confirm "Confirm changes? [yN] " || exit 1
 }
@@ -143,8 +142,8 @@
 update_version() {
 	local path="$1"
 	local sed_expr="$2"
-		# sed -E --in-place='' -e "s/VERSION =.+/VERSION = \"$version_replace\"/" setup.py
-		# sed -E --in-place='' -e "s/__version__ =.+/__version__ = \"$version_replace\"/" python2/httplib2/__init__.py python3/httplib2/__init__.py
+		# sed -E --in-place='' -e "s/VERSION =.+/VERSION = '$version_replace'/" setup.py
+		# sed -E --in-place='' -e "s/__version__ =.+/__version__ = '$version_replace'/" python2/httplib2/__init__.py python3/httplib2/__init__.py
 	echo "Updating file '$path'" >&2
 	if ! sed -E --in-place='' -e "$sed_expr" "$path" ; then
 		echo "sed error $?" >&2
@@ -210,7 +209,7 @@
 
 version_check() {
 	local need=$1
-	local version_setup=$(fgrep 'VERSION =' setup.py |tr -d " '\"" |cut -d\= -f2)
+	local version_setup=$(fgrep 'VERSION =' setup.py |tr -d " '" |cut -d\= -f2)
 	local version_py2=$(cd python2 ; python2 -Es -c 'import httplib2;print(httplib2.__version__)')
 	local version_py3=$(cd python3 ; python3 -Es -c 'import httplib2;print(httplib2.__version__)')
 	if [[ "$version_setup" != "$need" ]] ; then
diff --git a/setup.py b/setup.py
index b66d24e..33c8827 100755
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@
 import sys
 
 pkgdir = {"": "python%s" % sys.version_info[0]}
-VERSION = "0.18.1"
+VERSION = '0.15.0'
 
 
 # `python setup.py test` uses existing Python environment, no virtualenv, no pip.
diff --git a/tests/__init__.py b/tests/__init__.py
index 02a3ecf..496652b 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -75,7 +75,7 @@
                 chunk = b""
             else:
                 chunk = self._sock.recv(8 << 10)
-            # print("!!! recv", chunk)
+            # print('!!! recv', chunk)
             if not chunk:
                 self._end = True
                 if untilend:
@@ -406,12 +406,10 @@
             request = HttpRequest.from_buffered(buf)
             if request is None:
                 break
-            # print("--- debug request\n" + request.raw.decode("ascii", "replace"))
             i += 1
             request.client_sock = sock
             request.number = i
             response = request_handler(request=request)
-            # print("--- debug response\n" + response.decode("ascii", "replace"))
             sock.sendall(response)
             request.client_sock = None
             if not tick(request):
diff --git a/tests/test_http.py b/tests/test_http.py
index f61992c..97b52dc 100644
--- a/tests/test_http.py
+++ b/tests/test_http.py
@@ -622,57 +622,6 @@
         assert content == b"final content\n"
 
 
-def test_post_307():
-    # 307: follow with same method
-    http = httplib2.Http(cache=tests.get_cache_path(), timeout=1)
-    http.follow_all_redirects = True
-    r307 = tests.http_response_bytes(status=307, headers={"location": "/final"})
-    r200 = tests.http_response_bytes(status=200, body=b"final content\n")
-
-    with tests.server_list_http([r307, r200, r307, r200]) as uri:
-        response, content = http.request(uri, "POST")
-        assert response.previous.status == 307
-        assert not response.previous.fromcache
-        assert response.status == 200
-        assert not response.fromcache
-        assert content == b"final content\n"
-
-        response, content = http.request(uri, "POST")
-        assert response.previous.status == 307
-        assert not response.previous.fromcache
-        assert response.status == 200
-        assert not response.fromcache
-        assert content == b"final content\n"
-
-
-def test_change_308():
-    # 308: follow with same method, cache redirect
-    http = httplib2.Http(cache=tests.get_cache_path(), timeout=1)
-    routes = {
-        "/final": tests.make_http_reflect(),
-        "": tests.http_response_bytes(
-            status="308 Permanent Redirect",
-            add_date=True,
-            headers={"cache-control": "max-age=300", "location": "/final"},
-        ),
-    }
-
-    with tests.server_route(routes, request_count=3) as uri:
-        response, content = http.request(uri, "CHANGE", body=b"hello308")
-        assert response.previous.status == 308
-        assert not response.previous.fromcache
-        assert response.status == 200
-        assert not response.fromcache
-        assert content.startswith(b"CHANGE /final HTTP")
-
-        response, content = http.request(uri, "CHANGE")
-        assert response.previous.status == 308
-        assert response.previous.fromcache
-        assert response.status == 200
-        assert not response.fromcache
-        assert content.startswith(b"CHANGE /final HTTP")
-
-
 def test_get_410():
     # Test that we pass 410's through
     http = httplib2.Http()
@@ -694,42 +643,3 @@
         assert response.status == 200
         assert content == b"content"
         assert response["link"], "link1, link2"
-
-
-def test_custom_redirect_codes():
-    http = httplib2.Http()
-    http.redirect_codes = set([300])
-    with tests.server_const_http(status=301, request_count=1) as uri:
-        response, content = http.request(uri, "GET")
-        assert response.status == 301
-        assert response.previous is None
-
-
-def test_cwe93_inject_crlf():
-    # https://cwe.mitre.org/data/definitions/93.html
-    # GET /?q= HTTP/1.1      <- injected "HTTP/1.1" from attacker
-    # injected: attack
-    # ignore-http: HTTP/1.1  <- nominal "HTTP/1.1" from library
-    # Host: localhost:57285
-    http = httplib2.Http()
-    with tests.server_reflect() as uri:
-        danger_url = urllib.parse.urljoin(
-            uri, "?q= HTTP/1.1\r\ninjected: attack\r\nignore-http:"
-        )
-        response, content = http.request(danger_url, "GET")
-        assert response.status == 200
-        req = tests.HttpRequest.from_bytes(content)
-        assert req.headers.get("injected") is None
-
-
-def test_inject_space():
-    # Injecting space into request line is precursor to CWE-93 and possibly other injections
-    http = httplib2.Http()
-    with tests.server_reflect() as uri:
-        # "\r\nignore-http:" suffix is nuance for current server implementation
-        # please only pay attention to space after "?q="
-        danger_url = urllib.parse.urljoin(uri, "?q= HTTP/1.1\r\nignore-http:")
-        response, content = http.request(danger_url, "GET")
-        assert response.status == 200
-        req = tests.HttpRequest.from_bytes(content)
-        assert req.uri == "/?q=%20HTTP/1.1%0D%0Aignore-http:"
diff --git a/tests/test_proxy.py b/tests/test_proxy.py
index edafe01..375367f 100644
--- a/tests/test_proxy.py
+++ b/tests/test_proxy.py
@@ -32,22 +32,20 @@
     pi = httplib2.proxy_info_from_url("http://zoidberg:fish@someproxy:99")
     assert pi.proxy_host == "someproxy"
     assert pi.proxy_port == 99
-    assert pi.proxy_user == "zoidberg"
-    assert pi.proxy_pass == "fish"
+    assert pi.proxy_user == b"zoidberg"
+    assert pi.proxy_pass == b"fish"
 
 
-def test_from_env(monkeypatch):
-    assert os.environ.get("http_proxy") is None
-    monkeypatch.setenv("http_proxy", "http://myproxy.example.com:8080")
+def test_from_env():
+    os.environ["http_proxy"] = "http://myproxy.example.com:8080"
     pi = httplib2.proxy_info_from_environment()
     assert pi.proxy_host == "myproxy.example.com"
     assert pi.proxy_port == 8080
 
 
-def test_from_env_https(monkeypatch):
-    assert os.environ.get("http_proxy") is None
-    monkeypatch.setenv("http_proxy", "http://myproxy.example.com:80")
-    monkeypatch.setenv("https_proxy", "http://myproxy.example.com:81")
+def test_from_env_https():
+    os.environ["http_proxy"] = "http://myproxy.example.com:80"
+    os.environ["https_proxy"] = "http://myproxy.example.com:81"
     pi = httplib2.proxy_info_from_environment("https")
     assert pi.proxy_host == "myproxy.example.com"
     assert pi.proxy_port == 81
@@ -59,10 +57,10 @@
     assert pi is None
 
 
-def test_applies_to(monkeypatch):
-    monkeypatch.setenv("http_proxy", "http://myproxy.example.com:80")
-    monkeypatch.setenv("https_proxy", "http://myproxy.example.com:81")
-    monkeypatch.setenv("no_proxy", "localhost,example.com,.wildcard")
+def test_applies_to():
+    os.environ["http_proxy"] = "http://myproxy.example.com:80"
+    os.environ["https_proxy"] = "http://myproxy.example.com:81"
+    os.environ["no_proxy"] = "localhost,example.com,.wildcard"
     pi = httplib2.proxy_info_from_environment()
     assert not pi.applies_to("localhost")
     assert pi.applies_to("www.google.com")
@@ -73,18 +71,18 @@
     assert not pi.applies_to("pub.sub.wildcard")
 
 
-def test_noproxy_trailing_comma(monkeypatch):
-    monkeypatch.setenv("http_proxy", "http://myproxy.example.com:80")
-    monkeypatch.setenv("no_proxy", "localhost,other.host,")
+def test_noproxy_trailing_comma():
+    os.environ["http_proxy"] = "http://myproxy.example.com:80"
+    os.environ["no_proxy"] = "localhost,other.host,"
     pi = httplib2.proxy_info_from_environment()
     assert not pi.applies_to("localhost")
     assert not pi.applies_to("other.host")
     assert pi.applies_to("example.domain")
 
 
-def test_noproxy_star(monkeypatch):
-    monkeypatch.setenv("http_proxy", "http://myproxy.example.com:80")
-    monkeypatch.setenv("NO_PROXY", "*")
+def test_noproxy_star():
+    os.environ["http_proxy"] = "http://myproxy.example.com:80"
+    os.environ["NO_PROXY"] = "*"
     pi = httplib2.proxy_info_from_environment()
     for host in ("localhost", "169.254.38.192", "www.google.com"):
         assert not pi.applies_to(host)
@@ -173,35 +171,3 @@
         http = httplib2.Http(proxy_info=proxy_info)
         with tests.assert_raises(httplib2.socks.Socks5AuthError):
             http.request(uri, "GET")
-
-
-def test_functional_noproxy_star_http(monkeypatch):
-    def handler(request):
-        if request.method == "CONNECT":
-            return tests.http_response_bytes(
-                status="400 Expected direct", headers={"connection": "close"},
-            )
-        return tests.http_response_bytes()
-
-    with tests.server_request(handler) as uri:
-        monkeypatch.setenv("http_proxy", uri)
-        monkeypatch.setenv("no_proxy", "*")
-        http = httplib2.Http()
-        response, _ = http.request(uri, "GET")
-        assert response.status == 200
-
-
-def test_functional_noproxy_star_https(monkeypatch):
-    def handler(request):
-        if request.method == "CONNECT":
-            return tests.http_response_bytes(
-                status="400 Expected direct", headers={"connection": "close"},
-            )
-        return tests.http_response_bytes()
-
-    with tests.server_request(handler, tls=True) as uri:
-        monkeypatch.setenv("https_proxy", uri)
-        monkeypatch.setenv("no_proxy", "*")
-        http = httplib2.Http(ca_certs=tests.CA_CERTS)
-        response, _ = http.request(uri, "GET")
-        assert response.status == 200