From: Patrick Monnerat <patrick@monnerat.net>
Date: Sun, 8 Oct 2017 15:20:13 +0000 (+0100)
Subject: mime: be tolerant about setting twice the same header list in a part.
X-Git-Tag: curl-7_56_1~52
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=93e62adde88b6ae29767d977b6a813df21c32f02;p=curl

mime: be tolerant about setting twice the same header list in a part.
---

diff --git a/lib/mime.c b/lib/mime.c
index 496f5e6fb..7cfce6ae8 100644
--- a/lib/mime.c
+++ b/lib/mime.c
@@ -1356,7 +1356,8 @@ CURLcode curl_mime_headers(curl_mimepart *part,
     return CURLE_BAD_FUNCTION_ARGUMENT;
 
   if(part->flags & MIME_USERHEADERS_OWNER) {
-    curl_slist_free_all(part->userheaders);
+    if(part->userheaders != headers)  /* Allow setting twice the same list. */
+      curl_slist_free_all(part->userheaders);
     part->flags &= ~MIME_USERHEADERS_OWNER;
   }
   part->userheaders = headers;