[networking] Add `keep_header_casing` extension (#11652)

Authored by: coletdjnz, Grub4K

Co-authored-by: coletdjnz <coletdjnz@protonmail.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/yt_dlp/networking/_websockets.py b/yt_dlp/networking/_websockets.py
index ec55567da..7e5ab4600 100644
--- a/yt_dlp/networking/_websockets.py
+++ b/yt_dlp/networking/_websockets.py
@@ -116,6 +116,7 @@ class WebsocketsRH(WebSocketRequestHandler):
         extensions.pop('timeout', None)
         extensions.pop('cookiejar', None)
         extensions.pop('legacy_ssl', None)
+        extensions.pop('keep_header_casing', None)
 
     def close(self):
         # Remove the logging handler that contains a reference to our logger
@@ -123,15 +124,16 @@ class WebsocketsRH(WebSocketRequestHandler):
         for name, handler in self.__logging_handlers.items():
             logging.getLogger(name).removeHandler(handler)
 
-    def _send(self, request):
-        timeout = self._calculate_timeout(request)
-        headers = self._merge_headers(request.headers)
+    def _prepare_headers(self, request, headers):
         if 'cookie' not in headers:
             cookiejar = self._get_cookiejar(request)
             cookie_header = cookiejar.get_cookie_header(request.url)
             if cookie_header:
                 headers['cookie'] = cookie_header
 
+    def _send(self, request):
+        timeout = self._calculate_timeout(request)
+        headers = self._get_headers(request)
         wsuri = parse_uri(request.url)
         create_conn_kwargs = {
             'source_address': (self.source_address, 0) if self.source_address else None,