Description:
------------
See below.

Reproduce code:
---------------
1?
<?php

$url = "http://localhost/";
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, array("Hello" => "World"));
curl_setopt($ch, CURLOPT_URL, $url);
$copy = curl_copy_handle($ch);
curl_close($ch);

2?
<?php

$url = "http://localhost/";
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, array("Hello" => "World"));
curl_setopt($ch, CURLOPT_URL, $url);
$copy = curl_copy_handle($ch);
curl_close($ch);
curl_exec($copy);
curl_close($copy);

Expected result:
----------------
No SIGSEGV.

Actual result:
--------------
1?
*** glibc detected *** sapi/cli/php: double free or corruption (fasttop): 0x0a663260 ***
======= Backtrace: =========
/lib/i686/cmov/libc.so.6[0xb65a81d4]
/lib/i686/cmov/libc.so.6(cfree+0x96)[0xb65aa186]
/usr/local/lib/libcurl.so.4(curl_formfree+0x8a)[0xb74533ca]
sapi/cli/php[0x819c1af]
sapi/cli/php(zend_llist_destroy+0x33)[0x8612f05]
sapi/cli/php(zend_llist_clean+0x11)[0x8612f71]
sapi/cli/php[0x81a0a40]
sapi/cli/php[0x81a0d81]
sapi/cli/php[0x86321e4]
sapi/cli/php(zend_hash_del_key_or_index+0x192)[0x862f5d9]
sapi/cli/php(_zend_list_delete+0xa0)[0x8631df4]
sapi/cli/php(_zval_dtor_func+0x198)[0x861cb28]
sapi/cli/php[0x860cfcc]
sapi/cli/php(_zval_ptr_dtor+0xb8)[0x860d3b1]
sapi/cli/php(_zval_ptr_dtor_wrapper+0x21)[0x861cf08]
sapi/cli/php[0x862fa96]
sapi/cli/php(zend_hash_graceful_reverse_destroy+0x3e)[0x862fc1a]
sapi/cli/php[0x860c5bb]
sapi/cli/php[0x861f79a]
sapi/cli/php(php_request_shutdown+0x682)[0x8590ac0]
sapi/cli/php[0x87035c7]
/lib/i686/cmov/libc.so.6(__libc_start_main+0xe5)[0xb654f775]
sapi/cli/php[0x8078a91]


2?
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb631a6f0 (LWP 4050)]
0xb74ef368 in curl_formfree () from /usr/local/lib/libcurl.so.4
Current language:  auto; currently asm
(gdb) bt
#0  0xb74ef368 in curl_formfree () from /usr/local/lib/libcurl.so.4
#1  0xb74ef37c in curl_formfree () from /usr/local/lib/libcurl.so.4
#2  0x0819c1af in curl_free_post (post=0xaa1741c) at /home/felipe/dev/php5/ext/curl/interface.c:1246
#3  0x08612f05 in zend_llist_destroy (l=0xaa17230) at /home/felipe/dev/php5/Zend/zend_llist.c:114
#4  0x08612f71 in zend_llist_clean (l=0xaa17230) at /home/felipe/dev/php5/Zend/zend_llist.c:126
#5  0x081a0a40 in _php_curl_close_ex (ch=0xaa17128, tsrm_ls=0xa7aa4b8) at /home/felipe/dev/php5/ext/curl/interface.c:2302
#6  0x081a0d81 in _php_curl_close (rsrc=0xaa174d8, tsrm_ls=0xa7aa4b8) at /home/felipe/dev/php5/ext/curl/interface.c:2343
#7  0x086321e4 in list_entry_destructor (ptr=0xaa174d8) at /home/felipe/dev/php5/Zend/zend_list.c:184
#8  0x0862f5d9 in zend_hash_del_key_or_index (ht=0xa7ac7d4, arKey=0x0, nKeyLength=0, h=5, flag=1) at /home/felipe/dev/php5/Zend/zend_hash.c:497
#9  0x08631df4 in _zend_list_delete (id=5, tsrm_ls=0xa7aa4b8) at /home/felipe/dev/php5/Zend/zend_list.c:58
#10 0x081a09b5 in zif_curl_close (ht=1, return_value=0xaa16fe8, return_value_ptr=0x0, this_ptr=0x0, return_value_used=0, tsrm_ls=0xa7aa4b8)
    at /home/felipe/dev/php5/ext/curl/interface.c:2279