mime: fix the binary encoder to handle large data properly

New test 666 checks this is effective.
As upload buffer size is significant in this kind of tests, shorten it
in similar test 652.

Fixes #4860
Closes #4833
Reported-by: RuurdBeerstra on github

3 files changed, 128 insertions, 2 deletions

diff --git a/tests/libtest/Makefile.inc b/tests/libtest/Makefile.inc
index a8a148e66..ab2680c97 100644
--- a/tests/libtest/Makefile.inc
+++ b/tests/libtest/Makefile.inc
@@ -22,7 +22,7 @@ noinst_PROGRAMS = chkhostname libauthretry libntlmconnect                \
  lib571 lib572 lib573 lib574 lib575 lib576        lib578 lib579 lib582   \
  lib583 lib585 lib586 lib587 lib589 lib590 lib591 lib597 lib598 lib599   \
  lib643 lib644 lib645 lib650 lib651 lib652 lib653 lib654 lib655 lib658   \
- lib659 lib661 lib667 lib668 \
+ lib659 lib661 lib666 lib667 lib668 \
  lib670 lib671 lib672 lib673 \
  lib1156 \
  lib1500 lib1501 lib1502 lib1503 lib1504 lib1505 lib1506 lib1507 lib1508 \
@@ -349,6 +349,9 @@ lib659_CPPFLAGS = $(AM_CPPFLAGS)
 lib661_SOURCES = lib661.c $(SUPPORTFILES)
 lib661_CPPFLAGS = $(AM_CPPFLAGS)
 
+lib666_SOURCES = lib666.c $(SUPPORTFILES)
+lib666_CPPFLAGS = $(AM_CPPFLAGS)
+
 lib667_SOURCES = lib667.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
 lib667_LDADD = $(TESTUTIL_LIBS)
 lib667_CPPFLAGS = $(AM_CPPFLAGS)
diff --git a/tests/libtest/lib652.c b/tests/libtest/lib652.c
index 5c9cba5fb..3d247d27b 100644
--- a/tests/libtest/lib652.c
+++ b/tests/libtest/lib652.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2020, 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
@@ -105,6 +105,9 @@ int test(char *URL)
   /* send a multi-part mail */
   test_setopt(curl, CURLOPT_MIMEPOST, mime);
 
+  /* Shorten upload buffer. */
+  test_setopt(curl, CURLOPT_UPLOAD_BUFFERSIZE, 16411L);
+
   /* get verbose debug output please */
   test_setopt(curl, CURLOPT_VERBOSE, 1L);
 
diff --git a/tests/libtest/lib666.c b/tests/libtest/lib666.c
new file mode 100644
index 000000000..c75936eeb
--- /dev/null
+++ b/tests/libtest/lib666.c
@@ -0,0 +1,120 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2020, 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
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+#include "test.h"
+
+#include "memdebug.h"
+
+static char buffer[17000]; /* more than 16K */
+
+int test(char *URL)
+{
+  CURL *curl = NULL;
+  CURLcode res = CURLE_OK;
+  curl_mime *mime = NULL;
+  curl_mimepart *part;
+  size_t i;
+
+  /* Checks huge binary-encoded mime post. */
+
+  /* Create a buffer with pseudo-binary data. */
+  for(i = 0; i < sizeof(buffer); i++)
+    if(i % 77 == 76)
+      buffer[i] = '\n';
+    else
+      buffer[i] = (char) (0x41 + i % 26); /* A...Z */
+
+  if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
+    fprintf(stderr, "curl_global_init() failed\n");
+    return TEST_ERR_MAJOR_BAD;
+  }
+
+  curl = curl_easy_init();
+  if(!curl) {
+    fprintf(stderr, "curl_easy_init() failed\n");
+    res = (CURLcode) TEST_ERR_MAJOR_BAD;
+    goto test_cleanup;
+  }
+
+  /* Build mime structure. */
+  mime = curl_mime_init(curl);
+  if(!mime) {
+    fprintf(stderr, "curl_mime_init() failed\n");
+    res = (CURLcode) TEST_ERR_MAJOR_BAD;
+    goto test_cleanup;
+  }
+  part = curl_mime_addpart(mime);
+  if(!part) {
+    fprintf(stderr, "curl_mime_addpart() failed\n");
+    res = (CURLcode) TEST_ERR_MAJOR_BAD;
+    goto test_cleanup;
+  }
+  res = curl_mime_name(part, "upfile");
+  if(res) {
+    fprintf(stderr, "curl_mime_name() failed\n");
+    goto test_cleanup;
+  }
+  res = curl_mime_filename(part, "myfile.txt");
+  if(res) {
+    fprintf(stderr, "curl_mime_filename() failed\n");
+    goto test_cleanup;
+  }
+  res = curl_mime_data(part, buffer, sizeof(buffer));
+  if(res) {
+    fprintf(stderr, "curl_mime_data() failed\n");
+    goto test_cleanup;
+  }
+  res = curl_mime_encoder(part, "binary");
+  if(res) {
+    fprintf(stderr, "curl_mime_encoder() failed\n");
+    goto test_cleanup;
+  }
+
+  /* First set the URL that is about to receive our mime mail. */
+  test_setopt(curl, CURLOPT_URL, URL);
+
+  /* Post form */
+  test_setopt(curl, CURLOPT_MIMEPOST, mime);
+
+  /* Shorten upload buffer. */
+  test_setopt(curl, CURLOPT_UPLOAD_BUFFERSIZE, 16411L);
+
+  /* get verbose debug output please */
+  test_setopt(curl, CURLOPT_VERBOSE, 1L);
+
+  /* include headers in the output */
+  test_setopt(curl, CURLOPT_HEADER, 1L);
+
+  /* Perform the request, res will get the return code */
+  res = curl_easy_perform(curl);
+
+test_cleanup:
+
+  /* always cleanup */
+  curl_easy_cleanup(curl);
+
+  /* now cleanup the mime structure */
+  curl_mime_free(mime);
+
+  curl_global_cleanup();
+
+  return res;
+}