From f2565a62da98879ac60fc17b633a88021f37faa9 Mon Sep 17 00:00:00 2001
From: "Evgeny Grin (Karlson2k)" <k2k@narod.ru>
Date: Sun, 13 Mar 2022 20:31:45 +0300
Subject: [PATCH] MHD_set_response_options(): check whether the new flags could
 be used

---
 src/microhttpd/response.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/microhttpd/response.c b/src/microhttpd/response.c
index e12b44a8..fbee6308 100644
--- a/src/microhttpd/response.c
+++ b/src/microhttpd/response.c
@@ -895,8 +895,15 @@ MHD_set_response_options (struct MHD_Response *response,
   enum MHD_Result ret;
   enum MHD_ResponseOptions ro;
 
+  if ( (0 != (response->flags & MHD_RF_INSANITY_HEADER_CONTENT_LENGTH)) &&
+       (0 == (flags & MHD_RF_INSANITY_HEADER_CONTENT_LENGTH)))
+  { /* Request to remove MHD_RF_INSANITY_HEADER_CONTENT_LENGTH flag */
+    if (0 != (response->flags_auto & MHD_RAF_HAS_CONTENT_LENGTH))
+      return MHD_NO;
+  }
   ret = MHD_YES;
   response->flags = flags;
+
   va_start (ap, flags);
   while (MHD_RO_END != (ro = va_arg (ap, enum MHD_ResponseOptions)))
   {