From abc7f804218a983e88c3a00512697ddfd02ba075 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=A1clav=20Slav=C3=ADk?= <vaclav@slavik.io>
Date: Tue, 7 May 2024 19:28:57 +0200
Subject: [PATCH] Support gzip or deflate encoded responses

---
 src/download.cpp | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/download.cpp b/src/download.cpp
index 5c90e546..daffb9c3 100644
--- a/src/download.cpp
+++ b/src/download.cpp
@@ -40,6 +40,9 @@
 #ifndef HTTP_PROTOCOL_FLAG_HTTP2
     #define HTTP_PROTOCOL_FLAG_HTTP2 0x2
 #endif
+#ifndef INTERNET_OPTION_HTTP_DECODING
+	#define INTERNET_OPTION_HTTP_DECODING 65
+#endif
 
 
 namespace winsparkle
@@ -188,8 +191,9 @@ void WaitUntilSignaledWithTerminationCheck(Event& event, Thread *thread)
                                 public functions
  *--------------------------------------------------------------------------*/
 
-void DownloadFile(const std::string& url, IDownloadSink *sink, Thread *onThread, const std::string &headers, int flags)
+void DownloadFile(const std::string& url, IDownloadSink* sink, Thread* onThread, const std::string& headers_, int flags)
 {
+    std::string headers = headers_;
     char url_path[2048];
     URL_COMPONENTSA urlc;
     memset(&urlc, 0, sizeof(urlc));
@@ -214,6 +218,13 @@ void DownloadFile(const std::string& url, IDownloadSink *sink, Thread *onThread,
     DWORD dwOption = HTTP_PROTOCOL_FLAG_HTTP2;
     InternetSetOptionW(inet, INTERNET_OPTION_ENABLE_HTTP_PROTOCOL, &dwOption, sizeof(dwOption));
 
+    if (IsWindowsVistaOrGreater())
+    {
+        DWORD dwEnableHttpDecoding = TRUE;
+        InternetSetOptionW(inet, INTERNET_OPTION_HTTP_DECODING, &dwEnableHttpDecoding, sizeof(dwEnableHttpDecoding));
+        headers += "Accept-Encoding: gzip, deflate\r\n";
+    }
+
     // Never allow local caching, always contact the server for both
     // appcast feeds and downloads. This is useful in case of
     // misconfigured servers.