1 files changed, 80 insertions, 1 deletions

diff --git a/lib/mime.c b/lib/mime.c
index 457000a..e0853a9 100644
--- a/lib/mime.c
+++ b/lib/mime.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -1140,6 +1140,78 @@ void curl_mime_free(curl_mime *mime)
   }
 }
 
+CURLcode Curl_mime_duppart(curl_mimepart *dst, const curl_mimepart *src)
+{
+  curl_mime *mime;
+  curl_mimepart *d;
+  const curl_mimepart *s;
+  CURLcode res = CURLE_OK;
+
+  /* Duplicate content. */
+  switch(src->kind) {
+  case MIMEKIND_NONE:
+    break;
+  case MIMEKIND_DATA:
+    res = curl_mime_data(dst, src->data, (size_t) src->datasize);
+    break;
+  case MIMEKIND_FILE:
+    res = curl_mime_filedata(dst, src->data);
+    /* Do not abort duplication if file is not readable. */
+    if(res == CURLE_READ_ERROR)
+      res = CURLE_OK;
+    break;
+  case MIMEKIND_CALLBACK:
+    res = curl_mime_data_cb(dst, src->datasize, src->readfunc,
+                            src->seekfunc, src->freefunc, src->arg);
+    break;
+  case MIMEKIND_MULTIPART:
+    /* No one knows about the cloned subparts, thus always attach ownership
+       to the part. */
+    mime = curl_mime_init(dst->easy);
+    res = mime? curl_mime_subparts(dst, mime): CURLE_OUT_OF_MEMORY;
+
+    /* Duplicate subparts. */
+    for(s = ((curl_mime *) src->arg)->firstpart; !res && s; s = s->nextpart) {
+      d = curl_mime_addpart(mime);
+      res = d? Curl_mime_duppart(d, s): CURLE_OUT_OF_MEMORY;
+    }
+    break;
+  default:  /* Invalid kind: should not occur. */
+    res = CURLE_BAD_FUNCTION_ARGUMENT;  /* Internal error? */
+    break;
+  }
+
+  /* Duplicate headers. */
+  if(!res && src->userheaders) {
+    struct curl_slist *hdrs = Curl_slist_duplicate(src->userheaders);
+
+    if(!hdrs)
+      res = CURLE_OUT_OF_MEMORY;
+    else {
+      /* No one but this procedure knows about the new header list,
+         so always take ownership. */
+      res = curl_mime_headers(dst, hdrs, TRUE);
+      if(res)
+        curl_slist_free_all(hdrs);
+    }
+  }
+
+  /* Duplicate other fields. */
+  dst->encoder = src->encoder;
+  if(!res)
+    res = curl_mime_type(dst, src->mimetype);
+  if(!res)
+    res = curl_mime_name(dst, src->name);
+  if(!res)
+    res = curl_mime_filename(dst, src->filename);
+
+  /* If an error occurred, rollback. */
+  if(res)
+    Curl_mime_cleanpart(dst);
+
+  return res;
+}
+
 /*
  * Mime build functions.
  */
@@ -1855,6 +1927,13 @@ void Curl_mime_cleanpart(curl_mimepart *part)
   (void) part;
 }
 
+CURLcode Curl_mime_duppart(curl_mimepart *dst, const curl_mimepart *src)
+{
+  (void) dst;
+  (void) src;
+  return CURLE_OK;    /* Nothing to duplicate: always succeed. */
+}
+
 CURLcode Curl_mime_set_subparts(curl_mimepart *part,
                                 curl_mime *subparts, int take_ownership)
 {