fixed memory leak: CURLOPT_RESOLVE with multi interface

DNS cache entries populated with CURLOPT_RESOLVE were not properly freed
again when done using the multi interface.

Test case 1502 added to verify.

Bug: http://curl.haxx.se/bug/view.cgi?id=3575448
Reported by: Alex Gruz

2 files changed, 141 insertions, 1 deletions

diff --git a/tests/libtest/Makefile.inc b/tests/libtest/Makefile.inc
index 3cbc45aad..b568e190e 100644
--- a/tests/libtest/Makefile.inc
+++ b/tests/libtest/Makefile.inc
@@ -20,7 +20,7 @@ noinst_PROGRAMS = chkhostname \
   lib556 lib539 lib557 lib560 lib562 lib564 lib565 lib566 lib567 lib568	\
   lib569 lib570 lib571 lib572 lib573 lib582 lib583 lib585 lib586 lib587 \
   lib590 lib591 lib597 lib598 lib599 libauthretry libntlmconnect \
-  lib1500 lib1501
+  lib1500 lib1501 lib1502
 
 chkhostname_SOURCES = chkhostname.c $(top_srcdir)/lib/curl_gethostname.c
 chkhostname_LDADD = @CURL_NETWORK_LIBS@
@@ -191,6 +191,8 @@ lib1500_SOURCES = lib1500.c $(SUPPORTFILES) $(TESTUTIL)
 
 lib1501_SOURCES = lib1501.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
 
+lib1502_SOURCES = lib1502.c $(SUPPORTFILES)
+
 libauthretry_SOURCES = libauthretry.c $(SUPPORTFILES)
 
 libntlmconnect_SOURCES = libntlmconnect.c $(SUPPORTFILES) $(TESTUTIL)
diff --git a/tests/libtest/lib1502.c b/tests/libtest/lib1502.c
new file mode 100644
index 000000000..ec1058826
--- /dev/null
+++ b/tests/libtest/lib1502.c
@@ -0,0 +1,138 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2012, 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 http://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.
+ *
+ ***************************************************************************/
+/*
+ * Test case converted from bug report #3575448, identifying a memory leak in
+ * the CURLOPT_RESOLVE handling with the multi interface.
+ */
+
+#include "test.h"
+
+#include <stdio.h>
+#include <string.h>
+
+/* somewhat unix-specific */
+#include <sys/time.h>
+#include <unistd.h>
+
+int test(char *URL)
+{
+  CURL *ehandle;
+  CURLM *multi_handle;
+  char redirect[160];
+  CURLcode result = CURLE_NOT_BUILT_IN;
+  int still_running; /* keep number of running handles */
+
+  CURLMsg *msg; /* for picking up messages with the transfer status */
+  int msgs_left; /* how many messages are left */
+
+  /* DNS cache injection */
+  struct curl_slist *dns_cache_list;
+
+  sprintf(redirect, "google.com:%s:%s", libtest_arg2, libtest_arg3);
+
+  fprintf(stderr, "Redirect: %s\n", redirect);
+
+  dns_cache_list = curl_slist_append(NULL, redirect);
+
+  /* Allocate one CURL handle per transfer */
+  ehandle = curl_easy_init();
+
+  /* set the options (I left out a few, you'll get the point anyway) */
+  curl_easy_setopt(ehandle, CURLOPT_URL, URL);
+  curl_easy_setopt(ehandle, CURLOPT_HEADER, 1L);
+
+  curl_easy_setopt(ehandle, CURLOPT_RESOLVE, dns_cache_list);
+
+  /* init a multi stack */
+  multi_handle = curl_multi_init();
+
+  /* add the individual transfers */
+  curl_multi_add_handle(multi_handle, ehandle);
+
+  /* we start some action by calling perform right away */
+  curl_multi_perform(multi_handle, &still_running);
+
+  do {
+    struct timeval timeout;
+    int rc; /* select() return code */
+
+    fd_set fdread;
+    fd_set fdwrite;
+    fd_set fdexcep;
+    int maxfd = -1;
+
+    long curl_timeo = -1;
+
+    FD_ZERO(&fdread);
+    FD_ZERO(&fdwrite);
+    FD_ZERO(&fdexcep);
+
+    /* set a suitable timeout to play around with */
+    timeout.tv_sec = 1;
+    timeout.tv_usec = 0;
+
+    curl_multi_timeout(multi_handle, &curl_timeo);
+    if(curl_timeo >= 0) {
+      timeout.tv_sec = curl_timeo / 1000;
+      if(timeout.tv_sec > 1)
+        timeout.tv_sec = 1;
+      else
+        timeout.tv_usec = (curl_timeo % 1000) * 1000;
+    }
+
+    /* get file descriptors from the transfers */
+    curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
+
+    /* In a real-world program you OF COURSE check the return code of the
+       function calls.  On success, the value of maxfd is guaranteed to be
+       greater or equal than -1.  We call select(maxfd + 1, ...), specially in
+       case of (maxfd == -1), we call select(0, ...), which is basically equal
+       to sleep. */
+
+    rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
+
+    switch(rc) {
+    case -1:
+      /* select error */
+      break;
+    case 0: /* timeout */
+    default: /* action */
+      curl_multi_perform(multi_handle, &still_running);
+      break;
+    }
+  } while(still_running);
+
+  /* See how the transfers went */
+  while ((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
+    if (msg->msg == CURLMSG_DONE)
+      result = msg->data.result;
+  }
+
+  curl_multi_cleanup(multi_handle);
+
+  /* Free the CURL handles */
+  curl_easy_cleanup(ehandle);
+
+  curl_slist_free_all(dns_cache_list);
+
+  return (int)result;
+}