pingpong: return error when trying to send without connection

When imap_done() got called before a connection is setup, it would try
to "finish up" and dereffed a NULL pointer.

Test case 1553 managed to reproduce. I had to actually use a host name
to try to resolve to slow it down, as using the normal local server IP
will make libcurl get a connection in the first curl_multi_perform()
loop and then the bug doesn't trigger.

Fixes #1953
Assisted-by: Max Dymond

2 files changed, 113 insertions, 1 deletions

diff --git a/tests/libtest/Makefile.inc b/tests/libtest/Makefile.inc
index 59e3b281d..fe0433813 100644
--- a/tests/libtest/Makefile.inc
+++ b/tests/libtest/Makefile.inc
@@ -27,7 +27,7 @@ noinst_PROGRAMS = chkhostname libauthretry libntlmconnect                \
  lib1525 lib1526 lib1527 lib1528 lib1529 lib1530 lib1531 lib1532 lib1533 \
  lib1534 lib1535 lib1536 lib1537 lib1538 \
  lib1540 \
- lib1550 lib1551 lib1552 \
+ lib1550 lib1551 lib1552 lib1553 \
  lib1900 \
  lib2033
 
@@ -457,6 +457,9 @@ lib1551_CPPFLAGS = $(AM_CPPFLAGS)
 lib1552_SOURCES = lib1552.c $(SUPPORTFILES) $(TESTUTIL)
 lib1552_CPPFLAGS = $(AM_CPPFLAGS)
 
+lib1553_SOURCES = lib1553.c $(SUPPORTFILES) $(TESTUTIL)
+lib1553_CPPFLAGS = $(AM_CPPFLAGS)
+
 lib1900_SOURCES = lib1900.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
 lib1900_LDADD = $(TESTUTIL_LIBS)
 lib1900_CPPFLAGS = $(AM_CPPFLAGS)
diff --git a/tests/libtest/lib1553.c b/tests/libtest/lib1553.c
new file mode 100644
index 000000000..60be7c1a7
--- /dev/null
+++ b/tests/libtest/lib1553.c
@@ -0,0 +1,109 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2017, 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 "testutil.h"
+#include "warnless.h"
+#include "memdebug.h"
+
+#define TEST_HANG_TIMEOUT 60 * 1000
+
+static int xferinfo(void *p,
+                    curl_off_t dltotal, curl_off_t dlnow,
+                    curl_off_t ultotal, curl_off_t ulnow)
+{
+  (void)p;
+  (void)dlnow;
+  (void)dltotal;
+  (void)ulnow;
+  (void)ultotal;
+  fprintf(stderr, "xferinfo fail!\n");
+  return 1; /* fail as fast as we can */
+}
+
+int test(char *URL)
+{
+  CURL *curls = NULL;
+  CURLM *multi = NULL;
+  int still_running;
+  int i = 0;
+  int res = 0;
+  curl_mimepart *field = NULL;
+  curl_mime *mime = NULL;
+  int counter = 1;
+
+  start_test_timing();
+
+  global_init(CURL_GLOBAL_ALL);
+
+  multi_init(multi);
+
+  easy_init(curls);
+
+  mime = curl_mime_init(curls);
+  field = curl_mime_addpart(mime);
+  curl_mime_name(field, "name");
+  curl_mime_data(field, "value", CURL_ZERO_TERMINATED);
+
+  easy_setopt(curls, CURLOPT_URL, URL);
+  easy_setopt(curls, CURLOPT_HEADER, 1L);
+  easy_setopt(curls, CURLOPT_VERBOSE, 1L);
+  easy_setopt(curls, CURLOPT_MIMEPOST, mime);
+  easy_setopt(curls, CURLOPT_USERPWD, "u:s");
+  easy_setopt(curls, CURLOPT_XFERINFOFUNCTION, xferinfo);
+  easy_setopt(curls, CURLOPT_NOPROGRESS, 1L);
+
+  multi_add_handle(multi, curls);
+
+  multi_perform(multi, &still_running);
+
+  abort_on_test_timeout();
+
+  while(still_running && counter--) {
+    int num;
+    res = curl_multi_wait(multi, NULL, 0, TEST_HANG_TIMEOUT, &num);
+    if(res != CURLM_OK) {
+      printf("curl_multi_wait() returned %d\n", res);
+      res = TEST_ERR_MAJOR_BAD;
+      goto test_cleanup;
+    }
+
+    abort_on_test_timeout();
+
+    multi_perform(multi, &still_running);
+
+    abort_on_test_timeout();
+  }
+
+test_cleanup:
+
+  curl_mime_free(mime);
+  curl_multi_remove_handle(multi, curls);
+  curl_multi_cleanup(multi);
+  curl_easy_cleanup(curls);
+  curl_global_cleanup();
+
+  if(res)
+    i = res;
+
+  return i; /* return the final return code */
+}