Description:
------------
I'm trying to fetch a gzipped item from a web server and inflate it using the zlib inflate filter.

This causes a segfault.

Reproduce code:
---------------
<?php
	echo "Registered filters: --- \n\n";
	print_r(stream_get_filters());
	
	$opts = array(
		'http'=>array(
			'method'=>"GET",
			'header' => "Accept-Encoding:gzip"
		)
  	);
	$ctx = stream_context_create($opts);
	$url = "http://www.vectrex.org.uk/mark/web/test.txt.gz";
	
	$f = fopen($url, "r", false, $ctx);
	echo "appending filter...\n";
	stream_filter_append($f, 'zlib.inflate', STREAM_FILTER_READ);
	echo "filter appended, getting data....\n";
	$data = stream_get_contents($f);
	$metadata = stream_get_meta_data($f);
	fclose($f);
	
	echo "METADATA: ----- \n\n";
	print_r($metadata);
	
	echo "DATA: ----- \n\n";
	print $data ;
?>

Expected result:
----------------
The file will be printed uncompressed. This is intended to use the CLI SAPI.

Actual result:
--------------
Registered filters: --- 

Array
(
    [0] => string.rot13
    [1] => string.toupper
    [2] => string.tolower
    [3] => string.strip_tags
    [4] => convert.*
    [5] => convert.iconv.*
    [6] => zlib.*
)
appending filter...

Then it crashes with a segfault, stack trace is:

#0  0x0828efb8 in php_stream_bucket_unlink (bucket=0x86bac94, tsrm_ls=0x859b018)
    at /home/mark/unpack/php-5.1.2/main/streams/filter.c:228
#1  0x0828f46d in _php_stream_filter_append (chain=0x86bad74, filter=0x86b9934, 
    tsrm_ls=0x859b018) at /home/mark/unpack/php-5.1.2/main/streams/filter.c:370
#2  0x0826729a in apply_filter_to_stream (append=1, ht=0, return_value=0x86b8894, 
    return_value_ptr=0x0, this_ptr=0x0, return_value_used=0, tsrm_ls=0x859b018)
    at /home/mark/unpack/php-5.1.2/ext/standard/streamsfuncs.c:1085
#3  0x0826739c in zif_stream_filter_append (ht=0, return_value=0x0, return_value_ptr=0x0, 
    this_ptr=0x0, return_value_used=0, tsrm_ls=0x0)
    at /home/mark/unpack/php-5.1.2/ext/standard/streamsfuncs.c:1123
#4  0x082d5fee in zend_do_fcall_common_helper_SPEC (execute_data=0xbfaa9910, tsrm_ls=0x859b018)
    at zend_vm_execute.h:192
#5  0x082d56ec in execute (op_array=0x86b5994, tsrm_ls=0x859b018) at zend_vm_execute.h:92
#6  0x082bb1fc in zend_execute_scripts (type=8, tsrm_ls=0x859b018, retval=0x0, file_count=3)
    at /home/mark/unpack/php-5.1.2/Zend/zend.c:1101
#7  0x0827a064 in php_execute_script (primary_file=0xbfaabd90, tsrm_ls=0x859b018)
    at /home/mark/unpack/php-5.1.2/main/main.c:1720
#8  0x0832cf73 in main (argc=2, argv=0xbfaabe54)
    at /home/mark/unpack/php-5.1.2/sapi/cli/php_cli.c:1077