ensure consistent headers and params ordering

Necessary to avoid being labeled a bot and getting a CAPTCHA response
after solving a Cloudflare challenge.

gallery_dl/cloudflare.py

@@ -11,6 +11,7 @@
 import re
 import time
 import operator
+import collections
 import urllib.parse
 from . import text, exception
 from .cache import memcache
@@ -32,11 +33,9 @@ def solve_challenge(session, response, kwargs):
     parsed = urllib.parse.urlsplit(response.url)
     root = parsed.scheme + "://" + parsed.netloc
 
-    cf_kwargs = kwargs.copy()
-    headers = cf_kwargs["headers"] = (
-        kwargs["headers"].copy() if "headers" in kwargs else {})
-    params = cf_kwargs["params"] = (
-        kwargs["params"].copy() if "params" in kwargs else {})
+    cf_kwargs = {}
+    headers = cf_kwargs["headers"] = collections.OrderedDict()
+    params = cf_kwargs["params"] = collections.OrderedDict()
 
     page = response.text
     params["s"] = text.extract(page, 'name="s" value="', '"')[0]
@@ -49,7 +48,7 @@ def solve_challenge(session, response, kwargs):
 
     url = root + "/cdn-cgi/l/chk_jschl"
     cf_kwargs["allow_redirects"] = False
-    cf_response = session.request(response.request.method, url, **cf_kwargs)
+    cf_response = session.request("GET", url, **cf_kwargs)
 
     location = cf_response.headers.get("Location")
     if not location:

gallery_dl/extractor/common.py

@@ -127,10 +127,17 @@ class Extractor():
 
     def _init_headers(self):
         """Set additional headers for the 'session' object"""
-        self.session.headers["Accept-Language"] = "en-US,en;q=0.5"
-        self.session.headers["User-Agent"] = self.config(
+        headers = self.session.headers
+        headers.clear()
+
+        headers["User-Agent"] = self.config(
             "user-agent", ("Mozilla/5.0 (X11; Linux x86_64; rv:62.0) "
                            "Gecko/20100101 Firefox/62.0"))
+        headers["Accept"] = "*/*"
+        headers["Accept-Language"] = "en-US,en;q=0.5"
+        headers["Accept-Encoding"] = "gzip, deflate"
+        headers["Connection"] = "keep-alive"
+        headers["Upgrade-Insecure-Requests"] = "1"
 
     def _init_proxies(self):
         """Update the session's proxy map"""