Description:
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---
From manual page: http://www.php.net/function.stream-filter-append
---
Page should include that the function only returns a resource on success and returns false on error (still - regarding v5.2 change).

Regarding section "Return Values

Returns a resource which can be used to refer to this filter instance during a call to stream_filter_remove()."

(I'm trying to follow instructions around documentation user notes.)

Test script:
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var_dump(stream_filter_append(fopen('/dev/null','rb'),'null'));
/*
Same for all my versions:
PHP 5.3.29 with Suhosin-Patch (cli) (built: Oct  3 2015 20:34:12) (DEBUG)
PHP 5.4.32 (cli) (built: Oct  3 2015 20:40:05) 
PHP 5.5.16 (cli) (built: Oct  3 2015 20:49:43) 
PHP 5.6.0 (cli) (built: Jan 10 2016 22:08:51) 
*/
// My real example was via mod_php v5.6 @ Apache v2.2 appending zlib.deflate to an https stream, giving E_WARNING: stream_filter_append(): Filter failed to process pre-buffered data

Expected result:
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false or resource

Actual result:
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false