Prevent installing global url opener

WakaTime.py

@@ -40,9 +40,9 @@
 except ImportError:
     from configparser import ConfigParser, Error as ConfigParserError
 try:
-    from urllib2 import urlopen, urlretrieve, ProxyHandler, build_opener, install_opener, HTTPError
+    from urllib2 import Request, urlopen, HTTPError
 except ImportError:
-    from urllib.request import urlopen, urlretrieve, ProxyHandler, build_opener, install_opener
+    from urllib.request import Request, urlopen
     from urllib.error import HTTPError
 
 
@@ -847,83 +847,98 @@ def reportMissingPlatformSupport(osname, arch):
 
 
 def request(url, last_modified=None):
+    req = Request(url)
+    req.add_header('User-Agent', 'github.com/wakatime/sublime-wakatime')
+
     proxy = SETTINGS.get('proxy')
     if proxy:
-        opener = build_opener(ProxyHandler({
-            'http': proxy,
-            'https': proxy,
-        }))
-    else:
-        opener = build_opener()
+        req.set_proxy(proxy, 'https')
 
-    headers = [('User-Agent', 'github.com/wakatime/sublime-wakatime')]
     if last_modified:
-        headers.append(('If-Modified-Since', last_modified))
-
-    opener.addheaders = headers
-
-    install_opener(opener)
+        req.add_header('If-Modified-Since', last_modified)
 
     try:
-        resp = urlopen(url)
+        resp = urlopen(req)
         headers = dict(resp.getheaders()) if is_py2 else resp.headers
         return headers, resp.read(), resp.getcode()
     except HTTPError as err:
         if err.code == 304:
             return None, None, 304
         if is_py2:
-            ssl._create_default_https_context = ssl._create_unverified_context
-            try:
-                resp = urlopen(url)
-                headers = dict(resp.getheaders()) if is_py2 else resp.headers
-                return headers, resp.read(), resp.getcode()
-            except HTTPError as err2:
-                if err2.code == 304:
-                    return None, None, 304
-                log(DEBUG, err.read().decode())
-                log(DEBUG, err2.read().decode())
-                raise
-            except IOError:
-                raise
+            with SSLCertVerificationDisabled():
+                try:
+                    resp = urlopen(req)
+                    headers = dict(resp.getheaders()) if is_py2 else resp.headers
+                    return headers, resp.read(), resp.getcode()
+                except HTTPError as err2:
+                    if err2.code == 304:
+                        return None, None, 304
+                    log(DEBUG, err.read().decode())
+                    log(DEBUG, err2.read().decode())
+                    raise
+                except IOError:
+                    raise
         log(DEBUG, err.read().decode())
         raise
     except IOError:
         if is_py2:
-            ssl._create_default_https_context = ssl._create_unverified_context
-            try:
-                resp = urlopen(url)
-                headers = dict(resp.getheaders()) if is_py2 else resp.headers
-                return headers, resp.read(), resp.getcode()
-            except HTTPError as err:
-                if err.code == 304:
-                    return None, None, 304
-                log(DEBUG, err.read().decode())
-                raise
-            except IOError:
-                raise
+            with SSLCertVerificationDisabled():
+                try:
+                    resp = urlopen(url)
+                    headers = dict(resp.getheaders()) if is_py2 else resp.headers
+                    return headers, resp.read(), resp.getcode()
+                except HTTPError as err:
+                    if err.code == 304:
+                        return None, None, 304
+                    log(DEBUG, err.read().decode())
+                    raise
+                except IOError:
+                    raise
         raise
 
 
 def download(url, filePath):
+    req = Request(url)
+    req.add_header('User-Agent', 'github.com/wakatime/sublime-wakatime')
+
     proxy = SETTINGS.get('proxy')
     if proxy:
-        opener = build_opener(ProxyHandler({
-            'http': proxy,
-            'https': proxy,
-        }))
-    else:
-        opener = build_opener()
-    opener.addheaders = [('User-Agent', 'github.com/wakatime/sublime-wakatime')]
-
-    install_opener(opener)
+        req.set_proxy(proxy, 'https')
 
-    try:
-        urlretrieve(url, filePath)
-    except IOError:
-        if is_py2:
-            ssl._create_default_https_context = ssl._create_unverified_context
-            urlretrieve(url, filePath)
-        raise
+    with open(filePath, 'wb') as fh:
+        try:
+            resp = urlopen(req)
+            fh.write(resp.read())
+        except HTTPError as err:
+            if err.code == 304:
+                return None, None, 304
+            if is_py2:
+                with SSLCertVerificationDisabled():
+                    try:
+                        resp = urlopen(req)
+                        fh.write(resp.read())
+                        return
+                    except HTTPError as err2:
+                        log(DEBUG, err.read().decode())
+                        log(DEBUG, err2.read().decode())
+                        raise
+                    except IOError:
+                        raise
+            log(DEBUG, err.read().decode())
+            raise
+        except IOError:
+            if is_py2:
+                with SSLCertVerificationDisabled():
+                    try:
+                        resp = urlopen(url)
+                        fh.write(resp.read())
+                        return
+                    except HTTPError as err:
+                        log(DEBUG, err.read().decode())
+                        raise
+                    except IOError:
+                        raise
+            raise
 
 
 def is_symlink(path):
@@ -949,3 +964,13 @@ def createSymlink():
                 os.chmod(link, 509)  # 755
         except:
             log(traceback.format_exc())
+
+
+class SSLCertVerificationDisabled(object):
+
+    def __enter__(self):
+        self.original_context = ssl._create_default_https_context
+        ssl._create_default_https_context = ssl._create_unverified_context
+
+    def __exit__(self, *args, **kwargs):
+        ssl._create_default_https_context = self.original_context