fix #139

disallow cloning of MsgpackUnpacker instances to avoid crash when
attempted to do so

Author: m6w6

msgpack_class.c

@@ -512,6 +512,7 @@ void msgpack_init_class() /* {{{ */ {
     memcpy(&msgpack_unpacker_handlers, zend_get_std_object_handlers(),sizeof msgpack_unpacker_handlers);
     msgpack_unpacker_handlers.offset = XtOffsetOf(php_msgpack_unpacker_t, object);
     msgpack_unpacker_handlers.free_obj = php_msgpack_unpacker_free;
+    msgpack_unpacker_handlers.clone_obj = NULL;
 
 }
 /* }}} */

tests/issue139.phpt

@@ -0,0 +1,23 @@
+--TEST--
+Issue #139 (Segmentation fault when using cloned unpacker)
+--SKIPIF--
+<?php
+if (!extension_loaded("msgpack")) {
+   echo "skip"; 
+}
+--FILE--
+<?php
+try {
+	$unpacker = new \MessagePackUnpacker(true);
+	$unpacker = clone $unpacker; // <-- this line is causing the segmentation fault error
+	$unpacker->feed("\xc3");
+	$unpacker->execute();
+	$data = $unpacker->data();
+} catch (\Throwable $e) {
+	echo $e->getMessage(),"\n";
+}
+?>
+OK
+--EXPECT--
+Trying to clone an uncloneable object of class MessagePackUnpacker
+OK