mime: latch last read callback status.

In case a read callback returns a status (pause, abort, eof,
error) instead of a byte count, drain the bytes read so far but
remember this status for further processing.
Takes care of not losing data when pausing, and properly resume a
paused mime structure when requested.
New tests 670-673 check unpausing cases, with easy or multi
interface and mime or form api.

Fixes #4813
Reported-by: MrdUkk on github

13 files changed, 628 insertions, 13 deletions

diff --git a/lib/easy.c b/lib/easy.c
index d3a29f48b..b648e80c1 100644
--- a/lib/easy.c
+++ b/lib/easy.c
@@ -1003,6 +1003,14 @@ CURLcode curl_easy_pause(struct Curl_easy *data, int action)
     return CURLE_OK;
   }
 
+  /* Unpause parts in active mime tree. */
+  if((k->keepon & ~newstate & KEEP_SEND_PAUSE) &&
+     (data->mstate == CURLM_STATE_PERFORM ||
+      data->mstate == CURLM_STATE_TOOFAST) &&
+     data->state.fread_func == (curl_read_callback) Curl_mime_read) {
+    Curl_mime_unpause(data->state.in);
+  }
+
   /* put it back in the keepon */
   k->keepon = newstate;
 
diff --git a/lib/formdata.c b/lib/formdata.c
index 50a37e0e7..57ec6ad25 100644
--- a/lib/formdata.c
+++ b/lib/formdata.c
@@ -728,14 +728,10 @@ int curl_formget(struct curl_httppost *form, void *arg,
     if(!nread)
       break;
 
-    switch(nread) {
-    default:
-      if(append(arg, buffer, nread) != nread)
-        result = CURLE_READ_ERROR;
-      break;
-    case CURL_READFUNC_ABORT:
-    case CURL_READFUNC_PAUSE:
-      break;
+    if(nread > sizeof(buffer) || append(arg, buffer, nread) != nread) {
+      result = CURLE_READ_ERROR;
+      if(nread == CURL_READFUNC_ABORT)
+        result = CURLE_ABORTED_BY_CALLBACK;
     }
   }
 
diff --git a/lib/mime.c b/lib/mime.c
index 2571287c6..5f928a171 100644
--- a/lib/mime.c
+++ b/lib/mime.c
@@ -740,9 +740,19 @@ static size_t read_part_content(curl_mimepart *part,
 {
   size_t sz = 0;
 
-  if(part->readfunc)
-    sz = part->readfunc(buffer, 1, bufsize, part->arg);
-  return sz;
+  switch(part->lastreadstatus) {
+  case 0:
+  case CURL_READFUNC_ABORT:
+  case CURL_READFUNC_PAUSE:
+  case READ_ERROR:
+    break;
+  default:
+    if(part->readfunc)
+      sz = part->readfunc(buffer, 1, bufsize, part->arg);
+    part->lastreadstatus = sz;
+    break;
+  }
+  return part->lastreadstatus;
 }
 
 /* Read and encode part content. */
@@ -1031,6 +1041,7 @@ static int mime_part_rewind(curl_mimepart *part)
   if(res == CURL_SEEKFUNC_OK)
     mimesetstate(&part->state, targetstate, NULL);
 
+  part->lastreadstatus = 1; /* Successful read status. */
   return res;
 }
 
@@ -1073,6 +1084,7 @@ static void cleanup_part_content(curl_mimepart *part)
   part->datasize = (curl_off_t) 0;    /* No size yet. */
   cleanup_encoder_state(&part->encstate);
   part->kind = MIMEKIND_NONE;
+  part->lastreadstatus = 1; /* Successful read status. */
 }
 
 static void mime_subparts_free(void *ptr)
@@ -1238,6 +1250,7 @@ void Curl_mime_initpart(curl_mimepart *part, struct Curl_easy *easy)
 {
   memset((char *) part, 0, sizeof(*part));
   part->easy = easy;
+  part->lastreadstatus = 1; /* Successful read status. */
   mimesetstate(&part->state, MIMESTATE_BEGIN, NULL);
 }
 
@@ -1805,6 +1818,26 @@ CURLcode Curl_mime_prepare_headers(curl_mimepart *part,
   return ret;
 }
 
+/* Recursively reset paused status in the given part. */
+void Curl_mime_unpause(curl_mimepart *part)
+{
+  if(part) {
+    if(part->lastreadstatus == CURL_READFUNC_PAUSE)
+      part->lastreadstatus = 1; /* Successful read status. */
+    if(part->kind == MIMEKIND_MULTIPART) {
+      curl_mime *mime = (curl_mime *) part->arg;
+
+      if(mime) {
+        curl_mimepart *subpart;
+
+        for(subpart = mime->firstpart; subpart; subpart = subpart->nextpart)
+          Curl_mime_unpause(subpart);
+      }
+    }
+  }
+}
+
+
 #else /* !CURL_DISABLE_HTTP || !CURL_DISABLE_SMTP || !CURL_DISABLE_IMAP */
 
 /* Mime not compiled in: define stubs for externally-referenced functions. */
diff --git a/lib/mime.h b/lib/mime.h
index 431212579..c6d374ec1 100644
--- a/lib/mime.h
+++ b/lib/mime.h
@@ -125,6 +125,7 @@ struct curl_mimepart_s {
   mime_state state;                /* Current readback state. */
   const mime_encoder *encoder;     /* Content data encoder. */
   mime_encoder_state encstate;     /* Data encoder state. */
+  size_t lastreadstatus;           /* Last read callback returned status. */
 };
 
 CURLcode Curl_mime_add_header(struct curl_slist **slp, const char *fmt, ...);
@@ -147,6 +148,7 @@ size_t Curl_mime_read(char *buffer, size_t size, size_t nitems,
                       void *instream);
 CURLcode Curl_mime_rewind(curl_mimepart *part);
 const char *Curl_mime_contenttype(const char *filename);
+void Curl_mime_unpause(curl_mimepart *part);
 
 #else
 /* if disabled */
@@ -158,6 +160,7 @@ const char *Curl_mime_contenttype(const char *filename);
 #define Curl_mime_size(x) (curl_off_t) -1
 #define Curl_mime_read NULL
 #define Curl_mime_rewind(x) ((void)x, CURLE_NOT_BUILT_IN)
+#define Curl_mime_unpause(x)
 #endif
 
 
diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index 9afbf7437..99052007f 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -86,6 +86,7 @@ test635 test636 test637 test638 test639 test640 test641 test642 \
 test643 test644 test645 test646 test647 test648 test649 test650 test651 \
 test652 test653 test654 test655 test656 test658 test659 test660 test661 \
 test662 test663 test664 test665 \
+test670 test671 test672 test673 \
 \
 test700 test701 test702 test703 test704 test705 test706 test707 test708 \
 test709 test710 test711 test712 test713 test714 test715 test716 test717 \
diff --git a/tests/data/test644 b/tests/data/test644
index 4c9a501ed..256d3379a 100644
--- a/tests/data/test644
+++ b/tests/data/test644
@@ -50,6 +50,7 @@ Content-Type: multipart/form-data; boundary=----------------------------
 ------------------------------

 Content-Disposition: form-data; name="sendfile"; filename="postit2.c"

 

+
 </protocol>
 # CURLE_ABORTED_BY_CALLBACK (42)
 <errorcode>
diff --git a/tests/data/test670 b/tests/data/test670
new file mode 100644
index 000000000..19a51a4e0
--- /dev/null
+++ b/tests/data/test670
@@ -0,0 +1,72 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP POST
+MIME
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</data>
+<datacheck>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</datacheck>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+# tool is what to use instead of 'curl'
+<tool>
+lib670
+</tool>
+
+ <name>
+Request pause from mime read callback: multi
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/670
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strippart>
+s/^--------------------------[a-z0-9]*/------------------------------/
+s/boundary=------------------------[a-z0-9]*/boundary=----------------------------/
+</strippart>
+<protocol>
+POST /670 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Content-Length: 142

+Content-Type: multipart/form-data; boundary=----------------------------

+

+------------------------------

+Content-Disposition: form-data; name="field"

+

+AB

+--------------------------------

+</protocol>
+</verify>
+</testcase>
diff --git a/tests/data/test671 b/tests/data/test671
new file mode 100644
index 000000000..eada50a6e
--- /dev/null
+++ b/tests/data/test671
@@ -0,0 +1,72 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP POST
+MIME
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</data>
+<datacheck>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</datacheck>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+# tool is what to use instead of 'curl'
+<tool>
+lib671
+</tool>
+
+ <name>
+Request pause from mime read callback: easy
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/671
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strippart>
+s/^--------------------------[a-z0-9]*/------------------------------/
+s/boundary=------------------------[a-z0-9]*/boundary=----------------------------/
+</strippart>
+<protocol>
+POST /671 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Content-Length: 142

+Content-Type: multipart/form-data; boundary=----------------------------

+

+------------------------------

+Content-Disposition: form-data; name="field"

+

+AB

+--------------------------------

+</protocol>
+</verify>
+</testcase>
diff --git a/tests/data/test672 b/tests/data/test672
new file mode 100644
index 000000000..9c5f24556
--- /dev/null
+++ b/tests/data/test672
@@ -0,0 +1,72 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP POST
+FORM
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</data>
+<datacheck>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</datacheck>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+# tool is what to use instead of 'curl'
+<tool>
+lib672
+</tool>
+
+ <name>
+Request pause from form read callback: multi
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/672
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strippart>
+s/^--------------------------[a-z0-9]*/------------------------------/
+s/boundary=------------------------[a-z0-9]*/boundary=----------------------------/
+</strippart>
+<protocol>
+POST /672 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Content-Length: 142

+Content-Type: multipart/form-data; boundary=----------------------------

+

+------------------------------

+Content-Disposition: form-data; name="field"

+

+AB

+--------------------------------

+</protocol>
+</verify>
+</testcase>
diff --git a/tests/data/test673 b/tests/data/test673
new file mode 100644
index 000000000..efed2727b
--- /dev/null
+++ b/tests/data/test673
@@ -0,0 +1,72 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP POST
+FORM
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</data>
+<datacheck>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</datacheck>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+# tool is what to use instead of 'curl'
+<tool>
+lib673
+</tool>
+
+ <name>
+Request pause from form read callback: easy
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/673
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strippart>
+s/^--------------------------[a-z0-9]*/------------------------------/
+s/boundary=------------------------[a-z0-9]*/boundary=----------------------------/
+</strippart>
+<protocol>
+POST /673 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Content-Length: 142

+Content-Type: multipart/form-data; boundary=----------------------------

+

+------------------------------

+Content-Disposition: form-data; name="field"

+

+AB

+--------------------------------

+</protocol>
+</verify>
+</testcase>
diff --git a/tests/libtest/Makefile.inc b/tests/libtest/Makefile.inc
index 95ef8309b..9652f03fe 100644
--- a/tests/libtest/Makefile.inc
+++ b/tests/libtest/Makefile.inc
@@ -23,6 +23,7 @@ noinst_PROGRAMS = chkhostname libauthretry libntlmconnect                \
  lib583 lib585 lib586 lib587 lib589 lib590 lib591 lib597 lib598 lib599   \
  lib643 lib644 lib645 lib650 lib651 lib652 lib653 lib654 lib655 lib658   \
  lib659 lib661 \
+ lib670 lib671 lib672 lib673 \
  lib1156 \
  lib1500 lib1501 lib1502 lib1503 lib1504 lib1505 lib1506 lib1507 lib1508 \
  lib1509 lib1510 lib1511 lib1512 lib1513 lib1514 lib1515         lib1517 \
@@ -348,6 +349,22 @@ lib659_CPPFLAGS = $(AM_CPPFLAGS)
 lib661_SOURCES = lib661.c $(SUPPORTFILES)
 lib661_CPPFLAGS = $(AM_CPPFLAGS)
 
+lib670_SOURCES = lib670.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
+lib670_LDADD = $(TESTUTIL_LIBS)
+lib670_CPPFLAGS = $(AM_CPPFLAGS) -DLIB670
+
+lib671_SOURCES = lib670.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
+lib671_LDADD = $(TESTUTIL_LIBS)
+lib671_CPPFLAGS = $(AM_CPPFLAGS) -DLIB671
+
+lib672_SOURCES = lib670.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
+lib672_LDADD = $(TESTUTIL_LIBS)
+lib672_CPPFLAGS = $(AM_CPPFLAGS) -DLIB672
+
+lib673_SOURCES = lib670.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
+lib673_LDADD = $(TESTUTIL_LIBS)
+lib673_CPPFLAGS = $(AM_CPPFLAGS) -DLIB673
+
 lib1500_SOURCES = lib1500.c $(SUPPORTFILES) $(TESTUTIL)
 lib1500_LDADD = $(TESTUTIL_LIBS)
 lib1500_CPPFLAGS = $(AM_CPPFLAGS)
diff --git a/tests/libtest/lib643.c b/tests/libtest/lib643.c
index 7432dfce8..08c0f2e80 100644
--- a/tests/libtest/lib643.c
+++ b/tests/libtest/lib643.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, 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
@@ -41,11 +41,20 @@ struct WriteThis {
 static size_t read_callback(char *ptr, size_t size, size_t nmemb, void *userp)
 {
 #ifdef LIB644
+  static int count = 0;
   (void)ptr;
   (void)size;
   (void)nmemb;
   (void)userp;
-  return CURL_READFUNC_ABORT;
+  switch(count++) {
+  case 0: /* Return a single byte. */
+    *ptr = '\n';
+    return 1;
+  case 1: /* Request abort. */
+    return CURL_READFUNC_ABORT;
+  }
+  printf("Wrongly called >2 times\n");
+  exit(1); /* trigger major failure */
 #else
 
   struct WriteThis *pooh = (struct WriteThis *)userp;
diff --git a/tests/libtest/lib670.c b/tests/libtest/lib670.c
new file mode 100644
index 000000000..2e6040714
--- /dev/null
+++ b/tests/libtest/lib670.c
@@ -0,0 +1,259 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  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 <time.h>
+
+#include "test.h"
+
+#include "memdebug.h"
+
+#define PAUSE_TIME      2
+
+
+static const char name[] = "field";
+
+struct ReadThis {
+  CURL *easy;
+  time_t origin;
+  int count;
+};
+
+
+static size_t read_callback(char *ptr, size_t size, size_t nmemb, void *userp)
+{
+  struct ReadThis *pooh = (struct ReadThis *) userp;
+  time_t delta;
+
+  if(size * nmemb < 1)
+    return 0;
+
+  switch(pooh->count++) {
+  case 0:
+    *ptr = '\x41'; /* ASCII A. */
+    return 1;
+  case 1:
+    pooh->origin = time(NULL);
+    return CURL_READFUNC_PAUSE;
+  case 2:
+    delta = time(NULL) - pooh->origin;
+    *ptr = delta >= PAUSE_TIME? '\x42': '\x41'; /* ASCII A or B. */
+    return 1;
+  case 3:
+    return 0;
+  }
+  fprintf(stderr, "Read callback called after EOF\n");
+  exit(1);
+}
+
+#if !defined(LIB670) && !defined(LIB672)
+static int xferinfo(void *clientp, curl_off_t dltotal, curl_off_t dlnow,
+                    curl_off_t ultotal, curl_off_t ulnow)
+{
+  struct ReadThis *pooh = (struct ReadThis *) clientp;
+
+  (void) dltotal;
+  (void) dlnow;
+  (void) ultotal;
+  (void) ulnow;
+
+  if(pooh->origin) {
+    time_t delta = time(NULL) - pooh->origin;
+
+    if(delta >= 4 * PAUSE_TIME) {
+      fprintf(stderr, "unpausing failed: drain problem?\n");
+      return CURLE_ABORTED_BY_CALLBACK;
+    }
+
+    if(delta >= PAUSE_TIME)
+      curl_easy_pause(pooh->easy, CURLPAUSE_CONT);
+  }
+
+  return 0;
+}
+#endif
+
+int test(char *URL)
+{
+#if defined(LIB670) || defined(LIB671)
+  curl_mime *mime = NULL;
+  curl_mimepart *part;
+#else
+  CURLFORMcode formrc;
+  struct curl_httppost *formpost = NULL;
+  struct curl_httppost *lastptr = NULL;
+#endif
+#if defined(LIB670) || defined(LIB672)
+  CURLM *multi = NULL;
+  CURLMcode mres;
+  CURLMsg *msg;
+  int msgs_left;
+  int still_running = 0;
+#endif
+
+  struct ReadThis pooh;
+  CURLcode result;
+  int res = TEST_ERR_FAILURE;
+
+  /*
+   * Check proper pausing/unpausing from a mime or form read callback.
+   */
+
+  if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
+    fprintf(stderr, "curl_global_init() failed\n");
+    return TEST_ERR_MAJOR_BAD;
+  }
+
+  pooh.origin = (time_t) 0;
+  pooh.count = 0;
+  pooh.easy = curl_easy_init();
+
+  /* First set the URL that is about to receive our POST. */
+  test_setopt(pooh.easy, CURLOPT_URL, URL);
+
+  /* get verbose debug output please */
+  test_setopt(pooh.easy, CURLOPT_VERBOSE, 1L);
+
+  /* include headers in the output */
+  test_setopt(pooh.easy, CURLOPT_HEADER, 1L);
+
+#if defined(LIB670) || defined(LIB671)
+  /* Build the mime tree. */
+  mime = curl_mime_init(pooh.easy);
+  part = curl_mime_addpart(mime);
+  result = curl_mime_name(part, name);
+  if(!result)
+    res = curl_mime_data_cb(part, (curl_off_t) 2, read_callback,
+                            NULL, NULL, &pooh);
+
+  if(result) {
+    fprintf(stderr,
+            "Something went wrong when building the mime structure: %d\n",
+            (int) result);
+    goto test_cleanup;
+  }
+
+  /* Bind mime data to its easy handle. */
+  if(!res)
+    test_setopt(pooh.easy, CURLOPT_MIMEPOST, mime);
+#else
+  /* Build the form. */
+  formrc = curl_formadd(&formpost, &lastptr,
+                        CURLFORM_COPYNAME, name,
+                        CURLFORM_STREAM, &pooh,
+                        CURLFORM_CONTENTLEN, (curl_off_t) 2,
+                        CURLFORM_END);
+  if(formrc) {
+    fprintf(stderr, "curl_formadd() = %d\n", (int) formrc);
+    goto test_cleanup;
+  }
+
+  /* We want to use our own read function. */
+  test_setopt(pooh.easy, CURLOPT_READFUNCTION, read_callback);
+
+  /* Send a multi-part formpost. */
+  test_setopt(pooh.easy, CURLOPT_HTTPPOST, formpost);
+#endif
+
+#if defined(LIB670) || defined(LIB672)
+  /* Use the multi interface. */
+  multi = curl_multi_init();
+  mres = curl_multi_add_handle(multi, pooh.easy);
+  while(!mres) {
+    struct timeval timeout;
+    int rc = 0;
+    fd_set fdread;
+    fd_set fdwrite;
+    fd_set fdexcept;
+    int maxfd = -1;
+
+    mres = curl_multi_perform(multi, &still_running);
+    if(!still_running || mres != CURLM_OK)
+      break;
+
+    if(pooh.origin) {
+      time_t delta = time(NULL) - pooh.origin;
+
+      if(delta >= 4 * PAUSE_TIME) {
+        fprintf(stderr, "unpausing failed: drain problem?\n");
+        res = CURLE_OPERATION_TIMEDOUT;
+        break;
+      }
+
+      if(delta >= PAUSE_TIME)
+        curl_easy_pause(pooh.easy, CURLPAUSE_CONT);
+    }
+
+    FD_ZERO(&fdread);
+    FD_ZERO(&fdwrite);
+    FD_ZERO(&fdexcept);
+    timeout.tv_sec = 0;
+    timeout.tv_usec = 1000000 * PAUSE_TIME / 10;
+    mres = curl_multi_fdset(multi, &fdread, &fdwrite, &fdexcept, &maxfd);
+    if(mres)
+      break;
+#ifdef _WIN32
+    if(maxfd == -1)
+      Sleep(100);
+    else
+#endif
+    rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcept, &timeout);
+    if(rc == -1) {
+      fprintf(stderr, "Select error\n");
+      break;
+    }
+  }
+
+  if(mres != CURLM_OK)
+    for(;;) {
+      msg = curl_multi_info_read(multi, &msgs_left);
+      if(!msg)
+        break;
+      if(msg->msg == CURLMSG_DONE) {
+        result = msg->data.result;
+        res = (int) result;
+      }
+    }
+
+  curl_multi_remove_handle(multi, pooh.easy);
+  curl_multi_cleanup(multi);
+
+#else
+  /* Use the easy interface. */
+  test_setopt(pooh.easy, CURLOPT_XFERINFODATA, &pooh);
+  test_setopt(pooh.easy, CURLOPT_XFERINFOFUNCTION, xferinfo);
+  test_setopt(pooh.easy, CURLOPT_NOPROGRESS, 0L);
+  result = curl_easy_perform(pooh.easy);
+  res = (int) result;
+#endif
+
+
+test_cleanup:
+  curl_easy_cleanup(pooh.easy);
+#if defined(LIB670) || defined(LIB671)
+  curl_mime_free(mime);
+#else
+  curl_formfree(formpost);
+#endif
+
+  curl_global_cleanup();
+  return res;
+}